Study – Geothermal Asset
Management –
Guideline/Plan Template
Prepared for:
Kennisagenda Aardwarmte
Doc Ref:
J001916-01-PM-REP-001
Rev:
04
Date:
April 2018
Report
Study – Geothermal Asset Management – Guideline/Plan Template
Report
Client
Kennisagenda Aardwarmte
Document Title
Study – Geothermal Asset Management – Guideline/Plan Template
WG Reference Number
Client Reference Number (if applicable)
J001916-01-PM-REP-001
N/A
Contact
Arnaud Barré, Integrity Operation Manager
Arnaud.Barre@woodplc.com
Tel: +47 (0) 51 37 25 26
Wood
Kanalsletta 2,
NORWAY, 4033 Stavanger
Tel +47 (0) 51 37 25 00
www.woodplc.com
Revision
Date
Reason for Issue
Prepared
Checked
Approved
05
17/04/2018
Final for workshop
ABA
PW
OI
04
27/02/2018
Issued for client review
ABA
PW
OI
03
05/10/2017
Issued for client review
ABA
PW
OI
02
11/09/17
Re- Issue for Internal review
accounting for Strand A
ABA
OI
01
04/01/17
Issue for Internal review
ABA
IMC
INTELLECTUAL PROPERTY RIGHTS NOTICE AND DISCLAIMER
Wood Group Kenny Norge ASWood Group Kenny Norge AS, is the owner or the licensee of all intellectual property rights in this document (unless, and to the extent, we have agreed otherwise in a written contract with
our client). The content of the document is protected by confidentiality and copyright laws. All such rights are reserved. You may not modify or copy the document or any part of it unless we (or our client, as the case
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express written consent for such purposes. This document has been prepared for our client and not for any other person. Only our client may rely upon the contents of this document and then only for such purposes as
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Executive Summary
The first geothermal wells in the Netherlands were completed in 2007. In recent years, 11
geothermal doublets have been drilled. Kennisagenda’ and ‘the Dutch Geothermal Industry’
have identified a need to improve the asset management of their wells and surface facilities
based upon a review of current practice and consideration of improvements. The benefits of
proactive asset management can include, but are not limited to the following: improved
financial performance; informed asset investment decisions; managed risk; improved
services and outputs; demonstrated social responsibility; demonstrated compliance;
enhanced reputation; improved organisational sustainability; improved efficiency and
effectiveness, and last but not least management of technical and operation integrity ref./
6.
This report forms Kennisagenda Aardwarmte output from Corrosion Assessment, Wells
Materials Selection and Life Cycle Asset Management for Geothermal Energy Systems in
the Netherlands, which ran from 2016 through to 2017. This is Strand B; Strand A has
already been completed ref./ 9.
The objective of the study is to provide a draft Asset Management Guideline (AMG)
enabling the Dutch Geothermal Industry to develop asset management plan for geothermal
low enthalpy asset plants. The subset objectives are to define and standardise good asset
management practice covering the full life cycle, define the content of asset management
plans for geothermal energy systems, cover the entire asset life cycle from concept to
abandonment, create lean asset management plans which maximise production and safety
whilst optimising cost. Geothermal Asset Operators will develop or produce the plan from
the AM Guideline/AMP template.
The scope of the study includes surface infrastructure for both production and injection
wells. The primary loop includes booster and Injection pumps, heat exchanger, gas/water
separator and Piping.
The Study Introduction, section 1.0 presents the background, scope and objectives of the
study. The methodology used to develop the AM Guideline/AMP template is detailed in
section 2 and Appendix A. It includes the information collected through site visit, discussion
with DAGO representative and survey conducted.
The AM Guideline/Template is addressed in 3.0 and includes Appendix B to Appendix D.
Section 3.0 is further divided in the following sub –sections:
o
Section 3.1 is an introduction to the guideline;
o
Section 3.2 describes key regulation elements required for exploration, development
of licences and operation for Low Enthalpy Geothermal Asset in the Netherlands.
Relevant EU directive is also discussed.
o
Section 3.3 describes the overall Asset Management Process life cycle and
provides activity details for each phase of the Asset life cycle. Key engineering,
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construction, procurement activities best practices are presented as check list or
bullet list. Typical project risks (prior operation) are presented in section 3.3.2 and
3.3.3. Section 3.4 describes Risk Management prior operation, i.e. CAPEX phase.
o
Section 3.3.5 Present Asset integrity management best practice and requirements
during the Operational phase. It covers Integrity and Risk Assessment, Operational
philosophy and Requalification.
o
Section 3.3.6 addresses the abandonment phase best practices and requirements.
o
Having presented the process and the different phases, the development
requirement of the AMP phase by phase using the guideline is described in section
3.4.

The AMP requirements are addressed in section 3.5 Operational and Organisational
Asset Management system, in section 3.6 Reliability Management, and in section
3.7 Technical Asset Integrity management. It includes:
o
Inspection, Monitoring, Test, and Maintenance; design and operational data,
parameter to be monitored, performance indicator, typical Threats/Risk and
a generic Risk Assessment for the equipment, including when possible
mitigations.
o
Indicative frequency of inspection / maintenance,
o
Long term Historical & Planning
Through the study, activities have been identified which could potentially enable
deployment of a guideline and improvement of geothermal asset management in general.
These are detailed below:
1. Develop a common Asset database to collect Integrity and Reliability data,
including design information. The database should also contain a means for
sharing information among stakeholders in suitable formats. It will contribute
to have a better understanding of failures and their impact on current and
future LEGE Asset (see preliminary approach in section 3.6).
2. Continue to develop the existing collaborative platforms and forums to share
geothermal data from project development and operation. A Joint Industry
Project (JIP) collaboration format as in Oil & Gas Experience could be used.
3. Adapt Value Improvement Practices (VIP) as used in the Oil & Gas industry
to geothermal projects. VIP is underutilized in capital investment &
construction projects. Typical VIP methods include Setting Business
Priorities, Design to Capacity, Technology Selection, Constructability, etc.
this in particularly relevant for The Exploration & Development phase.
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Revision History (Optional)
Revision
Date
Comments
HOLDS
No.
Section
Comment
Signatory Legend
Revision
Role
Comments
04
Prepared
Arnaud Barre
Checked
Paul Wood
Approved
Ogo Ikenwilo
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Table of Contents
1.0
Introduction ..................................................................................................................... 10
2.0
Study Methodology ......................................................................................................... 12
2.1
Abbreviations .......................................................................................................................... 13
3.0
Asset Management Guideline ......................................................................................... 16
3.1
Introduction ............................................................................................................................. 16
3.2
Asset Management: Objectives and Regulation .................................................................... 17
Objectives.......................................................................................................................... 17
Regulatory ......................................................................................................................... 18
Guidelines and Standards ................................................................................................. 22
3.3
Asset Management Process & Phases during Life Cycle Phases .......................................... 23
Asset Management Process overview ............................................................................... 23
Exploration Phase/Global Study to Preparation for Drilling & Construction Phase
(“Voorbereidingsfase”) ....................................................................................................... 25
Drilling & Construction Phase ............................................................................................ 27
Risk Management Process - from Exploration until Drilling & Construction ........................ 28
Asset Integrity Management Plan During Production/Operation Phase ............................. 30
Geothermal Well Abandonment ......................................................................................... 35
3.4
Asset Management Plan - Development through the asset life cycle using the guideline ...... 37
Exploration Phase/Global Study to Preparation for Drilling & Construction Phase ............. 37
Drilling & Construction Phase ............................................................................................ 37
Production Phase to Abandonment ................................................................................... 38
3.5
Organisational and Operational Management Systems ......................................................... 39
Organisational Roles and Responsibilities ......................................................................... 39
Leadership Commitement and Policy ................................................................................ 40
Supply Chain Management and Knowledge Network ........................................................ 40
Competence and Training ................................................................................................. 42
HSE and Emergency Response ........................................................................................ 43
Management of Change .................................................................................................... 43
Incident, Preventive and Corrective Action Management System ...................................... 43
Lessons Learned ............................................................................................................... 44
Storage of Information – Documentation / Database ......................................................... 44
Performance Evaluation .................................................................................................... 47
Monitoring, Audit & Review ................................................................................................ 47
3.6
Reliability Studies.................................................................................................................... 48
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Reliability Prior to Operation/Production ............................................................................ 48
Reliability Data Collection during Operation/Production ..................................................... 48
Reliability, Availability and Maintainability (RAM) Analysis ................................................. 48
3.7
Technical Integrity Management............................................................................................. 50
Geothermal System Description ........................................................................................ 50
Design Information Per Equipment ................................................................................... 52
Monitoring Operation Data and Technical and Non-techncial Performance Indicators ....... 52
Generic Threats & Risk Assessment ................................................................................. 54
Christmas-tree and Well: Inspection, Testing & Maintenance Program .............................. 61
Surface Facilities : Inspection, Testing & Maintenance Program ........................................ 63
Periodic review : Integrity Assessment and Analysis ......................................................... 69
Indicative Inspection, Testing & Maintenance Frequencies ................................................ 70
Long Term Historical & Planning : Inspection, Testing & Maintenance ............................. 73
4.0
References ....................................................................................................................... 74
Methodology to develop the Asset Management Guideline ............................ A-1
A.1
General ................................................................................................................ A-1
A.2
Guideline contents rationale ................................................................................. A-1
A.3
Literature review................................................................................................... A-3
A.1
Asset Integrity Management Definitions ............................................................... A-4
Risk Assessment Methodology & Risk Matrices ............................................. B-6
Detailed Information on Standards ................................................................... C-1
Inspection, Testing, Monitoring Techniques .................................................... D-2
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List of Figures
Figure 1 Typical schematic sketch of a low enthalpy geothermal plant (source ref./ 36) ............... 13
Figure 2 Establishing Asset Management Process Prior to Operation/Production Phase .............. 24
Figure 3 Asset Management Process during Operation ................................................................ 25
Figure 4 Deliverables of an RBI Assessment for Inspection (ref./ 35) ........................................... 33
Figure 5 Maintenance Management System Cycle ....................................................................... 34
Figure 6 Basic P&A Plug ............................................................................................................... 36
Figure 7 Illustration Production Assurance terms (ref./ 24) ........................................................... 49
Figure 8 Diagram of Typical Production Low Enthalpy Dutch Geothermal Well ............................. 51
Figure 9 Hierarchy of elements of sustainable asset integrity management programme. (ref./ 19) A3
List of Tables
Table 3-1 Objectives ..................................................................................................................... 18
Table 3-2 Minimum checklist of tasks to be addressed during these phases................................. 26
Table 3-3 Risk Template ............................................................................................................... 29
Table 3-4 Minimum Maintenance & Inspection activities requirements.......................................... 32
Table 3-5 Role & Responsibilities ................................................................................................. 39
Table 3-6 Stakeholder List: Suppliers, Public, Client, etc. ............................................................. 40
Table 3-7 Leadership and Policy Item List .................................................................................... 40
Table 3-8 Supplier’s Qualifications ................................................................................................ 41
Table 3-9 Network......................................................................................................................... 41
Table 3-10 Organisation Competence and Training ...................................................................... 42
Table 3-11 Organisation Competence and Training – Planning .................................................... 42
Table 3-12 Technical Authority List ............................................................................................... 42
Table 3-13 List of Courses ............................................................................................................ 42
Table 3-14 List of Plan .................................................................................................................. 43
Table 3-15 MoC List for all phases ................................................................................................ 43
Table 3-16 Incident, Preventive and Corrective Action List for all phases ..................................... 44
Table 3-17 Lessons Learned List for all Phases ............................................................................ 44
Table 3-18 Minimum Documentation Management System Requirements ................................... 45
Table 3-19 Document& Data Storage System and Content .......................................................... 46
Table 3-20 Typical Master Document Register Content ................................................................ 47
Table 3-21 Minimum Audit and Review Plan ................................................................................. 47
Table 3-22 Reliability Data Collection............................................................................................ 48
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Table 3-23 Design data per equipment ......................................................................................... 52
Table 3-24 Typical Design Data For Well ...................................................................................... 52
Table 3-25 Production and Injection Well Integrity PI .................................................................... 53
Table 3-26 Production and Injection Surface Integrity Operating Window & Minimum KPI ............ 53
Table 3-27 Overall Geothermal Asset System Threats ................................................................. 55
Table 3-28 Well Threat Risk Assessment ..................................................................................... 57
Table 3-29 Threats, Risk Assessment and Mitigation for Surface Equipment................................ 59
Table 3-30: Frequencies ............................................................................................................... 71
Table 3-31 Basic Corrosion Monitoring Regime/Frequencies ........................................................ 72
Table 3-32: Inspection & Maintenance Planning template ............................................................. 73
Table 4-1 Risk = CoF x PoF (Quality) ......................................................................................... B-2
Table 4-2 Risk = CoF x PoF (Health) .......................................................................................... B-3
Table 4-3 Risk = CoF x PoF (Safety) .......................................................................................... B-3
Table 4-4 Risk = CoF x PoF (Environment) ................................................................................. B-4
Table 4-5 Risk = CoF x PoF (Public Acceptance) ....................................................................... B-4
Table 4-6 Risk Matrix .................................................................................................................. B-5
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1.0
Introduction
The first geothermal wells in the Netherlands were completed in 2007. In recent years, 11
geothermal doublets have been drilled. Client has identified a need to improve the asset
management of geothermal wells and surface facilities based upon a review of current
practice and consideration of improvements.
There is a need to define and standardise asset management practice covering the full life
cycle, and to transfer this knowledge effectively within the Industry to spread good practice.
An Asset Management plan should detail the HSSE management framework as well as the
economical delivery target and requirements. Furthermore, in addition to bringing good
practice to operational projects, the framework should ensure that knowledge relating to
HSSE, production and economic requirements are transferred to new geothermal projects.
The benefits of asset management can include, but are not limited to the following:

Improved financial performance

Informed asset investment decisions

Managed risk

Improved services and outputs

Demonstrated social responsibility

Demonstrated compliance

Enhanced reputation

Improved organizational sustainability

Improved efficiency and effectiveness
The objective of the study is to provide an Asset Management Guideline (AMG) enabling
the Dutch Geothermal Industry to develop lean, control and practical asset management
plan for their assets.
The guideline covers the entire asset life cycle and includes Concept and Drilling phase,
Surface Equipment, Well Construction and Design, Operation, Integrity, Inspection,
Maintenance and Safety.
The study also aims to facilitate knowledge–sharing and knowledge transfer in the area of
asset management for geothermal energy systems in the Netherlands through a workshop.
By providing tools to help deliver reliable and safe long-term operation of geothermal
systems, the study will increase asset performance, integrity and reliability within the HSE
framework prepared in another study. That includes maximising effective use of geothermal
energy (as opposed to non-renewable sources), maximising reliability and optimizing
maintenance, repair and other operating costs.
The Target Groups are the Dutch geothermal industry, asset operators, well designers,
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drilling contractors, surface facilities contractors and relevant institutions linked to the
geothermal industry in Netherlands.
The rest of the document is divided as follows;

Section 2 and Appendix A details the methodology

While section 3 is the actual Asset Management Guideline/Plan template. The
intention is that section 3 and Appendices B, C and D are easily extractable to make
an Asset Management plan.
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2.0
Study Methodology
The methodology that was utilised to develop the AMG is summarised below, more details
can be found in Appendix A.


Kick off meeting to agree deliverables and align expectations
A brief review of geothermal literature and risk approach

Review of asset management standards related to O&G and ISO 55000
covering Integrity and reliability of Asset

Incorporate and link relevant aspects from the past completed studies “Well
Integrity Management Guideline for Geothermal Wells” and “Geothermal
Corrosion study report” (Strand A of this proposal) to ensure the link between
design and operation

Review of available DAGO Integrity & Operation data (done via a survey and
also during a visit to select Operators facilities)

Risk assessment of relevant system threats to define appropriate inspection
methodologies, monitoring and integrity requirements on a generic basis (every
asset is different)
Development of the geothermal AM guideline including a set of tools & methods
to guide geothermal operators
A best practice and knowledge sharing workshop with Stakeholders


The guideline has been developed based on the following:

Oil & Gas standards and good practices, general Asset Management standards and
a web based literature review, all adapted to suit the Dutch geothermal industry;

The Hazid report ref./
threats;

Risk Assessment: Identification of Threat & Risk is covered from a Generic point of
view as it is asset dependent.

Visit and interview of two Operators, including working meeting with DAGO Rep
showed the diversity of asset size, asset complexity in term of production threats
and operation, diversity of business model (e.g. single owner, multi owner).
1 has been used to discuss and present key risks and
It is planned to conduct a Workshop after the study delivery. This will be presented at the
Workshop.
The AMG covers production and injection well and surface infrastructure primary loops only
for shallow geothermal sources as found in the Dutch geothermal context.
The guideline covers the usual set of systems and equipment in LEGE assets. The primary
loop includes Booster and Injection pumps, Heat Exchanger, Gas/Water Separator and
Piping (but. not the transport system to final user – e.g. Greenhouse) as shown in Figure 1.
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Development of the practical measures for asset management for the downhole part of the
system are based on the existing Project (ref./ 9).
Figure 1 Typical schematic sketch of a low enthalpy geothermal plant (source ref./ 36)
Details on the methodology and approach to develop the guideline are presented in
Appendix A.
2.1
Abbreviations
ALARP
As Low As Reasonably Practicable
AM
Asset Management or Asset Integrity Management
AMG
Asset Management Guideline/Plan template
AMP
Asset Management Plan
BARMM
Besluit Algemene Regels Milieu Mijnbouw).
BOP
Blowout Preventer
CAPEX
Capital Expenditure
CHP
Combined Heat and Power
CMMS
Computerized Maintenance Management System
CoF
Consequence of Failure
CVI
Close Visual Inspection
DAGO
Dutch Association of Geothermal Operators
DG
Decision Gate
DPI
Dye Penetrant Inspection
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EIS
Electrochemical Impedance Spectroscopy
ENM
Electrochemical Noise Measurements
ET
Eddy Current Testing
EU
European Union
FEED
Front End
Loading
FFS
Fitness for Service
GA
Geothermal Asset
GVI
Global Visual Inspection
HAZID
Hazard Identification
HSE
Health, Safety, and Environment
IMR
Inspection, Maintenance and Repair
IRIS
Internal Rotary Inspection System
IMT&M
Inspection, Monitoring, Test & Maintenance
KPI
Key Performance Indicator
LPR
Linear Polarization Resistance
LTE
Life Time Extension
MFL
Magnetic Flux Leakage
MIC
Microbial Induced Corrosion
MoC
Management of Change
MPI
Magnetic Particle Inspection
MTTF
Mean Time To Failure
NDE
Non Destructive Examination
NOGEPA
Netherlands Oil and Gas Exploration and Production
Association
O&G
Oil & Gas
OEM
Original Equipment Manufacturer
OPEX
Operational Expenditure
PI
Performance Indicator
PoF
Probability of Failure
RA
Risk Assessment
RAM
Reliability Availability and Maintainability
RBI
Risk Based Inspection
RBL
Radial Bond Log
Engineering
Development
or
Front-end
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RBM
Risk Based Maintenance
RCM
Risk Centred Maintenance
RFT
Remote Field Testing
RPN
Risk Priority Number
SCSSV
Surface-Controlled Subsurface Safety Valve
LEGE
SMART
SSM
TECOP
Low Enthalpy Geothermal Energy (also called Shallow
Geothermal Energy)
Specific, Measurable, Assignable, Realistic and Timerelated
State Supervision of Mines. Government body regulating
the Geothermal industry in the Netherlands
Technical, Economic, Commercial, Organisational,
Political
UT
Ultra Sonic
WG
Wood Group
WIM
Well Integrity Management
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3.0
Asset Management Guideline
3.1
Introduction
The factors which influence the type of assets that an organization requires to achieve its
objectives, and how the assets are managed, include the following:

The nature and purpose of the organization;

Its operating context;

Its financial/contractual constraints and regulatory requirements;

The needs and expectations of the organisation and its stakeholders.
These influencing factors need to be considered when establishing, implementing,
maintaining and continually improving asset management. Asset management translates
the organisation’s objectives into asset-related decisions, plans and activities, using a risk
based approach.
This Guideline provides guidance for the application of an Asset Management Plan and
system for a geothermal asset, referred to as an “Asset Management System”, in
accordance with the requirements of ISO 55001.
This LEGE guideline/plan template addresses:

Requirements and good practices in terms of the Asset Integrity Management plan
including key regulation references;

Covers LEGE Asset primary loop Surface Geothermal Plant and equipment, wells
equipment and Safety-Critical Elements associated with geothermal production
installations in the Netherlands;

Asset Integrity Management Requirements and Processes through the different
phases of the Asset Life Cycle. It specifically describe levels of information required
for the different phases as follows:
o
Business Asset Management systems requirements and processes such as
organisation, documentation, or training;
o
Reliability studies, Risk Management & Integrity Assessment process;
o
Primary loop systems threats & risk, Inspection Monitoring Testing &
Maintenance (IMT&T), Inspection and Frequency recommendation;
o
Risk Matrices and methodology.
The guideline is intended to be implemented by LEGE asset owners and personnel who are
involved in managing the asset lifecycle. The guideline is designed to inform and influence
operator's management systems in regard to Asset Integrity (AI) and Asset Management
(AM).
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3.2
Asset Management: Objectives and Regulation
Asset Management and Objectives shall be common to all assets owned by one operator.
Objectives
The Operator’s organisation shall consider the requirements of relevant stakeholders and of
other financial, technical, legal, regulatory and internal organisational requirements in the
asset management planning process.
The Assets of the Dutch geothermal operators varies from small to large and from simple to
complex in terms of operation, number of suppliers and services, production, technical
challenges and business models. As a result, the activities shall be sized according to the
business and asset as follows:
-
Perform a stakeholder management review and update it through the entire asset life
cycle.
-
Update objectives as per regulations.
-
Set objectives specific to assets - measurable, achievable within the timeframe, and
assignable to supplier or asset owner organisation (SMART1 principle good practice).
-
The objectives shall be communicated internally and externally as required and updated
when required.
The following objectives shall be set by Operator with their Stakeholder as a minimum. Until
the Operation phase only the Objective and Objectives Target shall be set:
1
SMART an acronym to set up objectives as follows: Specific – target a specific area for improvement. Measurable –
quantify or at least suggest an indicator of progress. Assignable – specify who will do it. Realistic – state what results can
realistically be achieved, given available resources. Time-related – specify when the result(s) can be achieved
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Table 3-1 Objectives
Objective
Objective Target
Measurement
Production
Flowrate
Production
Availability
Min and max flowrate
Flowrate
Hourly, Daily, monthly
etc.
- Based on yearly or
seasonal production
- Depending on client
needs
Number of days of
maintenance, of
production,
shutdown etc
Cost breakdown
structure plan vs
accrued
Cost breakdown
structure plan vs
accrued
Cost breakdown
structure plan vs
accrued
As per operational
parameters
Hourly, Daily, monthly
etc.
Operation Cost
Maintenance
Cost
Inspection Cost
Operational
Parameters
Training
Supplier
Performance
Improvement
Objectives
Typical
- Temperature min &
max to be delivered
Pressure
- Electrical power
consumption from grid
or CHP
- etc.
Type of training and
level
Quality of delivery,
delivery time, cost of
delivery
Once improvements
are identified, a target
is to be set
Number of course,
score achieved, etc.
Audit & review
evaluation
As per improvement
identified
Owner in
Organisation
Timeframe
Hourly, Daily, monthly
etc.
Hourly, Daily, monthly
etc.
Hourly, Daily, monthly
etc.
Hourly, Daily, monthly
etc.
As required
As required
Regulatory
The AMP shall address the social, cultural, political, legal, regulatory, technological, and
natural environment, whether these are international (i.e. relevant European Union
Directives for geothermal energy), national, regional or local; it shall also include
relationships with, and perceptions and values of, external stakeholders to understand the
requirement and the risk and opportunities.
Specific definitions for Low Enthalpy Geothermal Energy (LEGE) are implemented in the
Netherlands such as depth of geothermal resources, installed capacity & system size,
temperature and utilization of water or resources.
Geothermal Asset installations require a careful evaluation of the subsurface conditions and
environmental impact of the installations as part of the development process. Typical
project development steps include:

Early consultation or submission of an early application of the asset development;

Completion of a feasibility study demonstrating the proposed LEGE system
construction, system size and proposed operation modes (including required
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heating and cooling demands);

Full permit and application process including Environmental Impact Assessment this application process commonly includes the submission of detailed construction
drawings, detailed methodologies for the drilling and completion phase and the
confirmation of proposed selected contractors for the construction operations;

Detailed monitoring and data submission programme.
This is a non-exhaustive list.
A summary of the regulation requirement is provided here after ref./ 39:
Legal Framework:

Permitting procedures. Exploration and development of geothermal
resources under 500 meter depth are subject to licensing in accordance with
the Environmental Management Act and the Groundwater Act;
Exploration and development of deep geothermal resources (>500 meter depth) are subject
to licensing under the Mining Act and the Mining Regulation.
Application for Licenses
For both exploration and development licenses, the application file shall include:

General information such as the identification of the applicant;

Financial details such as the manner in which the applicant intends to
finance the intended exploration or possible production;

Technical details:

The local geological situation and subsurface description;

The area applied for with relevant map;

The period the license is applied for;

The proposed installations and operating methods during the drilling
activities including the safety precautions and methods to prevent
pollution and nuisance;

The effects on the sub-soil including risks of subsidence and
proposed measures to avoid them;

The expected timeframe of the proposed activities;

The potential interference with other applications;

The envisaged results.
Note : The completion of energy systems is based on the requirement of a system
achieving an energy balance where the volumes of water extracted and re-injected as well
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as the amount of energy extracted in the heating and cooling modes do not result in thermal
changes to the aquifer conditions.
For licences only, the application file for an exploration license shall include:

A program describing the reconnaissance and exploration activities the
applicant intends to carry out, the pertaining time schedule and techniques
that will be used;

A geological report detailing at least: the exploratory surveys used for the
support of the application and other geological data, the interpretation of this
data and the risk analysis used thereby as well as a description of the local
and regional geology.
As for the application file for a development license, it shall also include:

An estimate of the expected geothermal resource;

A multi-annual program describing the production activities to be performed,
techniques used thereby and an estimate of the annual production,
investment and operating costs;

The technical and financial capacity of the applicant;

The sense of responsibility for society that the applicant has demonstrated in
activities under previous licenses.
The competent authority and main steps of the process are summarised hereafter:


Exploration

The Minister of Economic Affairs is the competent authority;

Obtain a BARMM (Besluit Algemene Regels Milieu Mijnbouw) - a
notification that drilling is performed in a safe and environmentally
sound way.

Application is reviewed and advice is collected from TNO (GeoSciences Group), SODM (State Supervision of Mines) and the
Provincial executive of the province.
Development

The Minister of Economic Affairs is the competent authority;

A production license can be applied for once test drill has been done;

Advice from TNO, SODM, the Provincial executive and the Mining
Council.
Note that if a license for the production applies to an area in which a reservoir is present
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which can reasonably be expected to extend beyond the boundary of the license area, the
license holder is obliged to cooperate in reaching an agreement with the license holder of
the adjacent area.
A production plan is required. The plan shall address the following:

The expected geothermal resources and their location;

The commencement and duration of the production;

The manner of production and the activities relating thereto;

The expected annual production;

The annual cost of production;

The soil movement as a result of the production and the measures to prevent
such a soil movement.
A radioactivity baseline is recommended (see 3.5.5 HSE requirements framework.)
Operation phase and Abandonment

Annually, the licensee submits a report to the relevant Authority (e.g. the
Minister of Economic Affairs) on the progress of the execution of the
production plan and on any deviation from that plan.

In case of significant deviations, the licensee is required to submit an
update of the production plan, again to be approved by the Minister;

Report of water injected;

Environmental report (e.g. water from drain system);

Radioactivity.

Annually, the General Inspector of Mines shall issue an annual report to the
Minister on operations that took place during the year, including his
recommendations for the purpose of the efficient and dynamic handling of
future activities;

In the Netherlands, monitoring is implemented on larger scale systems only
as a measure to ensure the protection of groundwater resources and to
understand the hydraulic and thermal effects of the system on underground
aquifers. This monitoring process also includes annual reporting to authority;

LSA Norms. Radioactivity control is mandatory.
The abandonment of the wells will have to be carried out according to the Dutch rules and
regulations as described in the ‘Mijnbouwregeling’; Chapter 8.5. These regulations
prescribe the methods of abandonment for different well construction sections. These
methods dictate, in large, the work program and materials to be used and therefore the cost
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of the operation ref./ 41.
EU directives may impact the Netherlands geothermal asset. The Directive on Renewable
Energy Sources (2009/28/EC) has a binding definition of Geothermal Energy in the Article
2, which provides definition of geothermal systems. The rules protecting the environment in
geothermal regulatory frameworks cover principally water protection, control of emissions,
impact assessment and landscape assessment.
The following Directives are relevant for the geothermal industry:

Water Framework Directive, Directive 2000/60/EC

Natura 2000 Directive

Groundwater Directive

Surface Water Protection against Pollution under the Water Framework Directive

Environmental Impact Assessment Directive

Directive 2013/59/ Euratom, related to discharge of ionising radiation fluid
The requirement from these directives are summarised as follows:
o
Member States have the option to authorise the reinjection into the same
aquifer of water used for geothermal purposes;
o
Precautionary Principle

“Where there is scientific uncertainty as to the existence or extent of
risks to human health, the Community institutions may, by reason of
the precautionary principle, take protective measures without having
to wait until the reality and seriousness of those risks become fully
apparent”;
o
ALARP principle;
o
Monitoring of inlet and outlet temperatures, periodic monitoring of chemical,
composition of groundwater and/or surface water (including water quality).
Guidelines and Standards
Different Technical guidelines (ref./ 10) exist in the Netherlands related to LEGE systems
covering the following activities:

Distances for the completion of boreholes close to other third party properties

Design of groundwater wells

Technical drilling guidelines (under preparation)
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
Standards for Groundwater Protection
The good practice guideline documentation identified as fundamental to the support and
development of the LEGE sector into the mature regions like the Netherlands are further
detailed in Appendix C.
3.3
Asset Management Process & Phases during Life Cycle Phases
Asset Management Process overview
Asset management is based on a set of fundamentals.

Value: Assets exist to provide value to the organization and its stakeholders

Alignment: Asset management translates the organisational objectives into technical
and financial decisions, plans and activities.

Leadership: Leadership and workplace culture are key of realisation of value.

Assurance: Asset management gives assurance that asset will fulfil their required
purpose.
Figure 2 and Figure 3 aim to visualise the development of a geothermal well/surface system
AMP. It covers all phases from concept to decommissioning. The AM plan shall be
reviewed at least annually and updated as appropriate. An independent
verifier/auditor/examiner should review annually the day to day implementation of the AMP
in order to apply a “fresh set of eyes” to potential improvements.
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Figure 2 Establishing Asset Management Process Prior to Operation/Production Phase
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Figure 3 Asset Management Process during Operation
Kick off yearly process
Input data
Fit for service
Assessement
Yearly
- Inspection data
-Testing data
- Monitoring data
RBI
RA workshop
ITM plan/program
RA workshop
Maintenance plan/program
- Reliability data
Maintenance
data analysis
Maintenance
- Corrective data
- preventive data
RBM
Reliablity
assessement
Reliability plan/program
-Previous year data
- historical data
- earlier report
Output data
Reporting & Findings
- KPI
- failure report
- Database update
- procedured and
plans updates
- Etc
Analysis &
Assessment
Input/output
to/from Stakeholders
Yearly Periodic
Review
Continuous
Review
AM plan Update
Asset Integrity / Maintenance Management Process during geothermal operation/Production phase
The AMP shall gradually be developed as the geothermal asset project matures through
project phases; guidance is provided in section 3.4. One AMP shall be developed for each
asset.
The following section described in further details the key activities in each Asset life Cycle
phases. The following activities shall be executed by the operator together with contractor
and suppliers as part of the AM plan.
Exploration Phase/Global Study to Preparation for Drilling & Construction Phase
(“Voorbereidingsfase”)
This project phase focus will be on identification, selection and definition requirements. At
these stages the activities purposes are to support the decision processes of each project
gate.
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Table 3-2 Minimum checklist of tasks to be addressed during these phases
Define Design Basis
Design life of the asset, reservoir data, production target/requirements, etc.
Define preliminary Asset and Organisation philosophy
Define and describe information and philosophy such as production level, fluid composition, type of
wells, surface equipment’s, drilling information and constraints, reservoir information, Corrosion risk, etc.
Identify Risk & Opportunity and the show stoppers for each scenarios
Typical risk will be lack of information to take decision, uncertainty on data, nearby geothermal reservoir
data not available or confusing, drilling complex and costly, etc.
Material selection for geothermal wells and surface
Material selection for geothermal wells components and corrosion allowance according to design basis.
See WG INTETECH corrosion review and material selection for Geothermal systems and especially
wells for detail on how to select material (ref./ 9)
Define qualification testing required for the project and associated cost
List of test to be performed to validate technical solution according to design basis
Identify and describe different scenarios
List potential scenario, document changes of feasibility of the scenario to ease scenario selection
Establish Preliminary Integrity Management requirements by considering CAPEX
versus OPEX
that includes material selection, operation philosophy, equipment selection, consequences on
Maintenance Inspection, spare and repair workovers required for different options, etc
Seek and address lessons learnt from other projects to inform design decision
making
Use expert networks and geothermal organisation in general any source of information
Develop a list of specifications (to be included in contract) for next phase
List specification for suppliers and regulation requirements (see regulation section)
Identify resource requirements for the various project stages
Resource are personnel, engineering services, supplier, hardware, equipment (long lead item), access to
database, etc.
Address Economic viability of the assets for the key scenarios
Explain the business model, your client or market, the need and requirement from your client in term of
production target and availability
Recommended Minimum Functional Specification for wells (ref./ 40)
The well must be designed and constructed in a safe manner and account for the worse case such as:
Presence of gas and oil which is not detected and seismic activity, leading to explosion or
intoxication risks
Entry of free gas pocket while drilling
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Hereafter a non-exhaustive Risk list is presented. Large impact risks on project are
presented.

Reservoir condition (temperature, pressure, CO2 content, injection condition);

Heating or cooling capacity requirement and the ability to sustain these
requirements;

Uncertainty in geological situation and subsurface description, i.e. drilling risk;

Material Selection and Corrosion risk.
Drilling & Construction Phase
During this phase, the original design should align with the anticipated service life and be
factored into all design considerations. This means that:

Any deviations (see MoC in 3.5.6) to design during well construction; surface
equipment construction and commissioning should be recorded and addressed with
its impact on Operation, Workovers and Abandonment phase;

Control of change impact on OPEX, from CAPEX changes;

Update of Material selection;

Surface and Well Construction control (inspection & testing), including civil works;

Feed-back and lessons learned should be gathered, reviewed, and stored for future
/ new projects.
Hereafter a non-exhaustive Risk list is presented. Large impact risks (ref./ 1) on project are
presented:

Suppliers Cost and Delivery time overruns

Suppliers quality failure

o
Well construction (cementing, stuck pipe)
o
Surface construction
Drilling and well construction is one of the most expensive features of a geothermal
project. Drilling and well construction risks and any deviations shall be documented.
Safety equipment and procedure (e.g. BOP, Cementing job for isolation, etc.) shall
be addressed (ref./ 18).
Key risks will be:
o
Shallow Gas during drilling;
o
Existing geological characteristics and aquifer properties where systems are
proposed;
o
System size and suitability of the ground conditions;
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o
Flooding of asset during drilling;
o
Noise Pollution;
Other risks are:
o
Environmental pollution;
o
Impact on other sub surface users (nearby groundwater users or other sub
surface infrastructures);
o
Site preparation and restoration;
o
Temperature thresholds relating to re-injection or surface water discharge;
o
Thermal and hydrological effects with respect to the implications that the
system operation may have on sub-surface resource;
o
Guidelines specific to construction to prevent the cross contamination of
aquifers; Collector circulating fluid and leakage prevention measures and
borehole construction requirements;
o
Distances for the completion of boreholes neighbouring other third party
properties.
Risk Management Process - from Exploration until Drilling & Construction
Risk Management is paramount to understanding threats/risks related to geothermal
systems during the development phases or CAPEX phases. It may also reveal
opportunities. The risks and opportunities management allow the operator to:

Prevent, or reduce undesired effects;

Give assurance and demonstrate to others that the asset management system can
achieve its intended outcome(s);

Achieve continual improvement.
A risk register template (Table 3-3) to be regularly updated from Exploration until
Preparation Phase is presented hereafter. Risk assessment method & matrices are
described in Appendix A.

Regular Risk Review session should be held to keep the register and its
action/mitigation follow up, up-to date.

Risk shall cover Technical, Economic, Safety, Commercial, Organisational,
Regulation, and Community categories. Sufficient resources should be available to
address risks.
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Table 3-3 Risk Template
Category
Description
Risk/Opportunity ID
Number
Risk/Opportunity category
Technical, Economic, Safety, Commercial and Contract , Organisational,
Regulation, Community , Suppliers, ,etc
Risk/Opportunity description
“the Risk is …” add description ; the opportunity is ….” add description
Probability
Value from Risk matrix
Consequence Safety
Value from Risk matrix
Consequence Environment
Value from Risk matrix
Consequence Financial
Value from Risk matrix
Risk Rating
R=Probability x Consequence (highest of the 4, i.e. Quality, Safety,
Environment and Public opinion)
Mitigation and action
description
Can risk be transferred, reduced, eliminated- please describe the action
Mitigation and action status
Follow-up of the action
Risk Status
Open , closed
Risk Owner
Name
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Asset Integrity Management Plan During Production/Operation Phase
During the Production/Operational phase, a life cycle Asset Management process shall be
developed and maintained (see initiation in section 3.3.3), which describe how the asset will
be controlled and assessed during Production phase.
3.3.5.1 Integrity Assessment and Risk Assessment Steps
The AM plan shall describe when, how and why integrity assessment activities are to be
performed. Asset Integrity process during operation is summarised in Figure 3.
. The activities include:
1. Data and information collection gathering. These intend to provide information for
integrity and risk analysis and assessment. Inspection, monitoring and testing data
to be collected for each equipment and systems shall be established.
o
In Section 3.5.9 data and information to be collected and set up are further
described.
o
Technical data to be collected are further discussed in 3.7 (Inspection &
Maintenance program including their frequencies) and
o
In section 3.6.2 specific requirements related to Reliability are described.
2. Integrity analysis and Assessment activities. Integrity is about compliance with
intended Design Limits and Standards of the equipment/systems. The objective of
the Integrity Assessment activity is to ensure a full assessment of the facilities and
systems based on inspection findings, monitoring and test results and reported
events. In principle all integrity assessments start by screening analysis. In case
more complex integrity assessments are performed, more quantifiable analysis is
used.
o
See Performance indication and monitored data in section 3.7.3 data to be
monitored, assessed and analysed.
3. Risk Based Assessment Inspection and Maintenance
An anomaly (e.g. defect, pressure peak, CO2 Corrosion, etc.) can be critical or could
become with time. While the risk assessment purpose is to establish the current
condition of the anomaly, the ranking will help to provide appropriate actions and
allocate resource in term of inspection, monitoring, testing; it will also provide
recommendation in term of mitigation (e.g. preventive maintenance, repair,
replacement).
o
Section 3.3.5.2 Detailed RBI and RBM method.
o
An overview of typical Threats & Risk for LEGE assets are discussed in
section 3.7. As all LEGE assets are different, RBI and RBM must be run
based on this generic assessment.
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4. Asset Management planning. Based on previous activity (2 and 3) frequency of
inspection, maintenance, monitoring or testing and associated assessment can be
updated from baseline.
o
See section 3.7 for Indicative frequencies per equipment.
5. Inspection, Monitoring & Testing Programs.
These are established during construction phase and revised according to Risk
Assessment and Integrity Assessment.
Inspections may reveal degradation or failures of equipment and in these cases,
corrective measures must be taken to rectify, re-instate, and maintain the integrity
level. For most of the geothermal plant equipment, fixed intervals are used for the
maintenance and inspection activities. These intervals can range from weeks up to
several years, which can be based either on calendar time or usage.
o
Minimum maintenance & inspection activity requirements to be established
for each equipment are listed in Table 3-4.
o
Inspection, monitoring, testing and maintenance generic
recommendations by equipment are presented in section 3.6.
o
More information relating to the main inspection & monitoring techniques are
further detailed in Appendix D.
technical
6. Long Term Plan: it is important to maintain an Inspection, Monitoring, Testing &
Maintenance plan.
o
Template of how to build one is provided in section 3.7.9.
7. Mitigation activity. These are maintenance, repair or replacement activities to be
performed to reinstate and improve the asset integrity.
o
See section 3.5.9 for required documentation
8. Fit for service activity will provide, on a yearly basis, the current status of associated
equipment or components. It is recommended to have regular review during the
year.
o
See section 3.5.9 for required documentation
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Table 3-4 Minimum Maintenance & Inspection activities requirements
Description of requirements
Inspection, monitoring, testing
Program
Define reporting and alert criteria
Information
Inspection
See section 3.7 for technical details per equipment
Reporting criteria are criteria when an anomaly must be
reported during Inspection
Alert criteria is a criteria providing an alert during Monitoring
of Parameters
Maintenance
Maintenance programme, technique
and procedure
Define Maintenance criteria
Note:
See section 3.7 for technical details. Program should be risk
based and set procedure for:
- Corrective maintenance: The unscheduled
maintenance or repair to return items/equipment*).
Preventive maintenance: All actions carried out on
a planned, periodic, and specific schedule to keep
an item/equipment in stated working condition
through the process of checking and reconditioning.
Preventive maintenance can be time based (e.g.
cleaning filter on regular basis) or Conditioned
Based **)
Workload and resource based
*) it is crucial that corrective maintenance is kept at a minimum, with typically only non-critical
equipment chosen to be in that category.
**) Predictive maintenance: The use of advanced measurement and signal processing methods to
accurately diagnose item / equipment condition during operation, and intervene to maintain
equipment on an as-required basis in advance of any significant degradation / failure
In addition to the Integrity Assessment routines described above, un-planned events should
also be assessed following a similar process described above.
When potentially unacceptable damage or an abnormality is detected, an integrity
assessment should be performed and should include a thorough evaluation including the
possible impact on the safety and operation of the Geothermal Asset. This means
quantification, Root Cause identification, additional inspection, monitoring and testing if
required to mitigate further degradation; identification of common failures across other
assets should be performed.
Note that a temporary damaged Asset system can potentially be operated (see 3.3.5.3).
3.3.5.2 Risk-Based Inspection & Risk-Based Maintenance
Risked Based Inspection
Whilst there are a range of risk assessment processes, an evidence based approach (ref./
22 ) should be used to screen out threat categories which are not relevant to the specific
Geothermal asset plant (e.g. seismic activity is not relevant for all asset) when developing
initial RBI.
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This avoids in-depth focus and assessment of threats which can be qualitatively assessed.
Risk can be evaluated qualitatively (expert Judgement) and/or quantitatively (i.e.
modelling), depending on availability of input data, and feasibility / cost efficiency. RBI
should be carried out for all elements of the geothermal installations.
Risk-Based Inspection (RBI) will be used as a key decision making technique for inspection
planning. Risk comprises the Consequence of Failure (CoF) and the Probability of Failure
(PoF). It is a formal approach designed to aid the development of an optimised inspection
regime. This evaluation will be carried out as per risk matrices and Methodology given in
Appendix B.
Figure 4 summarizes the principle and benefit of an RBI.
Figure 4 Deliverables of an RBI Assessment for Inspection (ref./ 35)
Risk-Based Maintenance
A Risk Based Maintenance assessment using risk assessment methodology and matrices
(see appendix A) (see ref./ 37) shall be used to prioritize maintenance in order to optimize
maintenance resources available. The outcome of the RBM will define priority and
frequency/interval of maintenance tasks. A typical maintenance process system is
presented in Figure 5. It is recommended to follow this process.
The scope of the RBM will encompass all systems in the geothermal plant. This evaluation
will be carried out as per risk matrices given in Appendix B.
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Figure 5 Maintenance Management System Cycle
3.3.5.3 Operation Philosophies and Integrity Management
Operation/Production Philosophy and integrity management are closely related. Asset
Integrity in normal operation is covered by the AMP. However, any change of operation
might impact the AMP and shall be addressed.
An asset system with damage / anomalies may be operated temporarily under certain
conditions. However, an integrity assessment shall be performed to define the temporary
operational conditions that the system can be operated in.
So long as the defect has not been removed or repairs have been carried out, it must be
documented that the asset integrity and the specific safety level is maintained, which may
include reduced/new operational conditions and/or temporary precautions/measures (see
section 3.5.6 Management of Change ).
Changes in operating conditions have the potential to impact the operability and technical
integrity of the geothermal systems. Problems that can result from changes in operating
conditions are addressed in further details as follows:

Design data and Operational Procedure are detailed in section 3.7.2
3.3.5.4 Requalification and Life Time Extension
Re-qualification is a re-assessment of the design and operation under changed design
basis conditions. A re-qualification may be triggered by a change in the original design
basis, including an extension to the original design life, by not fulfilling the design basis or
by mistakes or shortcomings discovered during normal or abnormal operation. The impact
of changes / updates to the original design code(s) or other relevant/ recognised design
codes should also be assessed when required.
AMP shall be revised according to changes to ensure engineering and operation continuity
until re-assessment is completed.
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Geothermal Well Abandonment
The abandonment of a well requires sealing it in a permanently safe manner that precludes
the possibility of any internal well flows from the reservoir to shallower formation or to
surface.
The law (see section 3.2.2) explains how different sections of the well will have to be
technically abandoned using cement, possibly in combination with (physical) plugs, and
how the quality of the shut-off has to be tested.
The construction of individual wells will vary with respect to casing design, cement depths,
cement quality and completion. As a result, the work programs to abandon wells will differ.
The following main items are included in the abandonment:
1. Production well
a. Including well head (X-mas tree), ESP, Production tubing
2. Injection well
a. Including. well head (X-mas tree)
b. Injection tubing
3. Production installation and pipelines
a. Including separator, filters, injection pump(s), metering, etc.
b. Cleaning equipment of Naturally Occurring Radioactive Material (NORM)
4. Well site area
The whole anticipated closure and removal process will have to be described in an
abandonment or Closure Plan. The plan should contain a detailed description of how the
abandonment will be executed from a technical and operational perspective.
A study performed for DAGO (ref./ 41) shows that up to 4 concrete plugs located at
different well location might be required. More details about abandonment plan and cost
estimate can be found in ref./ 41.
Despite disparities around the world, the intent of abandonment operations is to achieve the
following:

Isolate and protect all freshwater zones;

Isolate all potential future urban zones;

Prevent in perpetuity leaks from or into the well;

Following permanent abandonment, the elevation and plan location of the top of the
remaining casing shall be surveyed and all surface equipment removed.
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Figure 6 Basic P&A Plug
Typical P & A Requirements are as follows

All distinct permeable zones penetrated by the well must be isolated, both from each
other and from surface by a minimum of one permanent barrier

Two permanent barriers from surface are required if a permeable zone is
hydrocarbon bearing (if any) or over-pressured and water-bearing

The position of permanent barriers must be set based on the actual geological
setting
Note that the well should be monitored for losses or gas flows between stages and
pressure tests should be undertaken where practicable to determine the integrity of
cement plug and casing if identify as a risk.
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3.4
Asset Management Plan - Development through the asset life cycle using the
guideline
This section defines how AMP is developed and contents of each phase using the
guideline.
Exploration Phase/Global Study to Preparation for Drilling & Construction Phase
During this phase the Asset Management Plan requires:
o
Initiate AM plan development,

Specifically address requirement in section 3.2.2,

Project risk as per section 3.3.4,

Organisational & Operational Asset Management as 3.5. Note the
plan shall contain the data available at the time.
o
Reliability study 3.6.1 shall be initiated
o
Need for Reliability study section 3.6.3 shall be decided
o
Address regulation as per requirements in section 3.2.2.
Drilling & Construction Phase
During this phase the Asset Management Plan requires to be further detailed.
o
Address regulation as per requirements in section 3.2.2,
o
Continue to develop Organisational & Operational Asset Management systems as
per 3.5. Specifically develop and establish Asset Management Plan for Operational
phase needs such as Asset Management documentation and data amongst others.
o
Technical Integrity Asset Management as per section 3.7, including:
o
Failure Mode and Effect Cause Analysis (FMECA) per equipment to Address
critical failure mode into the design
o
Develop an initial Risk Based Inspection (RBI) and Risk Based Maintenance
(RBM);
o
Acceptance Design criteria
o
Inspection, Test, Monitoring and Maintenance (IMT&M ) program and plan
per equipment
o
Equipment initial condition status baseline such as wall thickness of piping
(see details in section 3.7.6)
o
Detailed plans for hand-over including check-sheets of handover requirements for
Production & Operation shall be prepared;
o
Transfer of documents and databases relevant for the operational phase;
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o
Identification and cooperation with the project organisation to resolve any
engineering and/or technical concerns and issues;
In addition, specific Production/Operation activity shall be transferred:

Training of personnel on equipment’s maintenance, inspection and operation.
The following shall be considered depending of the geothermal asset risk profile:

Online methods and tools to support diagnostics and failure analysis to improve
maintenance and reliability growth shall be defined and implemented such as:
o
Seismic monitoring
o
Radioactivity monitoring
Production Phase to Abandonment
At this phase, the Asset Management Plan shall be fully completed:
o
Organisational & Operational Asset Management Systems section
completed and updated;
o
Technical Integrity Asset Management section 3.7 shall be completed and updated
with supplier information;
o
Reliability data collection system section 3.6.2 shall be set up and data to be
collected during Operation specified;

Integrity Management activities during Operation described in section 3.3.5.1 and
risk assessment, i.e. RBI & RBM (see section 3.3.5.2) further detailed in section 3.7.
shall be performed continuously;
3.5 shall be
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3.5
Organisational and Operational Management Systems
Equally important to Technical Asset Management; Organisational and Operational
management systems aspects must also be addressed.
Organisational Roles and Responsibilities
For an organisation, the key is to ensure clear roles & responsibilities and interface with
stakeholders to close any gaps. Operators shall address in the following tables:

Role & responsibilities.
o
Experience and skills shall drive the selection of the individual;
o
Example is provided in Grey. Role and title can change from one
organisation to another. Role and responsibility for the function listed must
be addressed;

Stakeholders interfacing with internal organisation;

The interfaces between functions.
For small Dutch LEGE organisation, one employee may cover several function presented in
the table hereafter.
Table 3-5 Role & Responsibilities
Function
Operation/
production
Inspection
Maintenance
Commercial Supply
chain
HSE
Asset Integrity
Technical services
(Supply chain)
Internal /external
reporting
Technical Authority
Others
Job
Title
Role and responsibility description
Years of
Name of the
experience person
In charge of day to day operation and
delivery
In charge of leading or performing Inspection
function
In charge of leading or performing
Maintenance function
In charge of Contract and commercial
In charge of safety
In charge of ensuring fit for purpose well and
surface equipment
In charge of technical delivery follow up
Reporting Asset status internally and
externally
Decide best technical solution for surface
or/and well
To be added as required
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Table 3-6 Stakeholder List: Suppliers, Public, Client, etc.
Stakeholder:
Services and
Products
Inspection service
Maintenance
services
Drilling services
Consultant services
Network and
industry association
Service or reporting
Person in charge
internally (Job Title)
Additional information
All equipment & Service
All equipment & Service
All equipment & Service
e.g. Law. Project
management, technical
services, etc.
Any network and
Association supporting
asset management
Leadership Commitement and Policy
Asset management leadership is demonstrated by top management positively influencing
the organisation. In common with other aspects of responsible and prudent operatorship,
sound Asset Integrity Management (AIM) is largely shaped by effective leadership which
should be expressed in the operator's HSE policy and Asset management system (in
Dutch: 'Veiligheid en Gezondheids- zorgsysteem'/ 'VG- systeem').
Note that Leadership Engagement is usually included as part of Asset Management best
practice. However, considering that LEGE organisations in Netherlands are usually small,
the associated activity should be dimensioned according to the company size. Nevertheless
less, the Operator should have a policy statement on how they will manage their asset,
personnel and the environment.
Table 3-7 Leadership and Policy Item List
Item
Owner
HSE Objectives
Owner site visit and/or
town-hall meeting
Owner meeting with all
personnel
Policy statement
Description of information
Information
Name of owner/accountable person
List objectives
Once year is recommended
Any additional information
Any additional information
Any additional information
To address importance of operation objective, Inspection
and maintenance, and review of system in place
.Quarterly is advised
A short statement that sets out the principles, Vision, and
priority by which the organisation intends to apply asset
management to achieve its objectives, and improvement.
Any additional information
Any additional information
Supply Chain Management and Knowledge Network
Supply chain risks from Concept to Operation should be identified, with careful control and
planning of all activities. Physical and service interfaces should be identified, agreed and
documented.
For the Dutch Geothermal operator, it is particularly important as the industry is in infancy
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phase where different uncertainties, new technical issues, or different operational
philosophy are new.
For a LEGE asset, Supplier control & Supplier qualification records shall ensure control of
cost, delivery time, and quality of the scope delivered from Concept to
Construction/commissioning (see detailed requirements in 3.3.2, 3.3.3 & 3.3.4), and
Planning of Inspection, Monitoring, Testing and maintenance supplier during Operation.
Supplier qualifications are addressed in Table 3-8.
It is also important to maintain a network of national/international services, organisation and
different subject matter experts to answer potential new issues and challenges or bring
additional knowledge. This is addressed in Table 3-9.
Table 3-8 Supplier’s Qualifications
Supplier name and service/product
Description of information
Does the selected Supplier have a track
record?
Are the supplier’s personnel qualified?
HSE track record
Information
Delivery on time, Cost and quality
How the Operator/Supplier interface is
managed for risk and engineering delivery?
Is the supplier informed about operator HSE
and Production Objectives
How is the Supplier/Operator informed of
changes during concept design, fabrication,
commissioning, production phase?
Does Supplier understand Engineering
requirements of equipment defined by
Operator?
Does Supplier understand Integrity, Inspection
and Maintenance requirements of equipment
defined by Operator?
Is the supplier optimizing OPEX / Capex as
per Operator requirement and needs?
Does the Contract Terms and Condition cover
all risks identified
Check CV’s and qualification
HSE Statistic, Environmental incident if any while
drilling, etc.
Check and justify
Check and justify
Check and justify
Check and justify
Check and justify
Check and justify
Check and justify. see Risk sections 3.3.4 and 3.3.5.2
Table 3-9 Network
Name and service/product
Description of Product & Services
Contact details
Description of the information, knowledge sharing, product or
services that can be provided by the network organisation
Dutch Geothermal Platform Organisation – sharing forum
Operator and Contractor
DAGO – Geothermal Operator Network
Contact details
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Competence and Training
Management of competence and training is key to a successful asset management
program and control of technical risk. Staff must be suitably trained and coached as per
their job and function. Basic professional and technical competence should be
supplemented where necessary with training in the management of ageing assets. Training
can be applied in different forms such as via industry work groups, seminars and formal
training courses both within and outside the industry. Resources & manning levels shall be
managed and controlled accordingly.
With respect to contractors and external service providers, their responsibilities and the
competence requirements should be documented in the scope or elsewhere in contracts
document (See 3.5.3 training).
Table 3-10 Organisation Competence and Training
Employee
Name
Job
Required
Function Qualification for job
Employee
1; job title
List training, experience
on the job as per job
description for the job
title or function
Current
Planned
qualification Training to
close the gap
Task allowed
List training,
experience
As per current skills
vs required training
list the task allowed
Training plan ,
description to
close the gap
Employee
2
Table 3-11 Organisation Competence and Training – Planning
Employee
Name
Employee 1;
job title
Employee 2
Course title
Planned date
Status
Completion date
Not started, on-going,
competed
Table 3-12 Technical Authority List
Employee Name
Employee 1; job title
Subject matter
List technical authority subject matter covered by employee
Table 3-13 List of Courses
Course
Description
Course name, organisation, location
Describe the course and qualification it provided
DAGO Geothermal Courses
BodemenergieNL, Euroform &
Stichting PAO (Netherlands) (ref./ 4)
VIA University College, School of
Technology and Business
(Denmark) (ref./ 4)
Basic courses as well as several specialised courses for different
target group including drilling companies, advisors/consultants and
local authorities
Shallow geothermal energy system development and installation
focuses on the different aspects related to LEGE systems
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HSE and Emergency Response
ALARP principle shall be observed in day to day AMP activities. As a result, HSE
requirements shall be implemented as per DAGO Zorgsysteem.
The AM plan shall also address a number of emergency plans to cover various emergency,
incident and associated repairs. For a LEGE Asset, the following emergency response plan
should be in place to re-instate the asset integrity in addition to plan for HSE purpose (see
DAGO Zorgsysteem).
Table 3-14 List of Plan
Plan
Surface equipment
emergency repair
plan
Well emergency
repair plan
Description and ref
Describe the purpose of the plan and give reference to a plan document:
Proposed content : leakage repair for piping and pressure vessels, piping
blockage; Valves leaks, Exchanger leaks and pressure vessels, piping blockage;
Valves leaks, Exchanger leaks; other component, define spare strategy for long
lead items, identified supplier and repair supplier
Describe the purpose of the plan and give reference to a plan document:
Xmas tree failure, ESP failure repair/spare plan, identified supplier and repair
supplier
Management of Change
The primary objective of a Management of Change (MoC) process is to ensure that
sufficient rigour is applied in terms of planning, assessment, documentation,
implementation and monitoring of changes affecting an installation or operation so that any
potentially adverse effects on Asset Integrity are identified and managed effectively to
mitigate adverse effects.
The AM organisation plays a key role in ensuring that all changes are communicated and
managed in a systematic manner and that all required stake holders are aware of the
changes and approval of changes is known. Changes should be consistently recorded and
assessed in terms of risk for the life cycle of the asset.
Table 3-15 MoC List for all phases
Change
description
Compone
nt
Project
Phase
Who should be
consulted &
informed
Approver
Status
Deadline
Describe the
change
Relevant
component
Exploration
development,
Construction,
Commissioning,
Operation and
Abandonment
List who is
impacted and
should be
consulted and
informed
PM,
Technical
Authority
Open,
ongoing,
closed
Deadline to
complete or
to take
decision
Incident, Preventive and Corrective Action Management System
Arrangements should be in place to ensure that all relevant preventive and corrective
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improvement actions arising from monitoring, audit / review are recorded, documented and
tracked to closure.
For incidents; their investigation, root cause identification and the resulting action must also
be recorded for continuous improvement purposes. Other methods exist such as forensic
engineering report (ref./ 17) which complement usual integrity and risk assessment.
Table 3-16 Incident, Preventive and Corrective Action List for all phases
Incident,
description
Preventive
and
Corrective
Action
Measure
Project
Phase
Who should
be
consulted &
informed
Approver
Status
Deadline
Describe the
incident and
relevant
component
Describe the
action
Exploration
development,
Construction,
Commissioning,
Operation and
Abandonment
List who is
impacted and
should be
consulted and
informed
PM,
Technical
Authority
Open,
Ongoing,
Closed
Deadline to
complete
or to take
decision
Lessons Learned
Lessons learned from assurance activities or from incidents should be captured and
communicated within the operator's organisation and across the wider industry as
necessary (see section 3.5.5). Learning from problem and exchanging data and information
across developing industries are crucial to the overall long-term viability and efficiency of
the geothermal asset.
Table 3-17 Lessons Learned List for all Phases
Component
Lesson
Learned
description
Recommend
ed Action
Project Phase
Distribution
list
Status
Relevant
component
Describe the
change
Describe action
Exploration
development,
Construction,
Commissioning,
Operation and
Abandonment
List who should
be informed
Open,
ongoing,
closed
Storage of Information – Documentation / Database
All assets should have all project life-cycle documentation/data available and associated
change recorded. This activity is often referred to as Life Cycle Information management
systems (LCI). The documentation sets out the design criteria by which the asset meets
safety, operational and other performance requirements.
All changes should be controlled and documented. Operators should demonstrate that
relevant, up-to-date documentation is readily accessible by maintaining an effective
Document Management System (see requirement Table 3-18).
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Operator shall define and list IT information system to store the different data &
documentation related to the life cycle of the asset (see Table 3-19).
Table 3-18 Minimum Documentation Management System Requirements
Item #
1
2
Requirements & Recommendations
Maintainable and up-to- date
documentation and database system
3
Design and set a documentation
format and system easing retrieval
and analysis of data & information
Review by Technical Authority
4
Identify a document/data Controller
4
Documentation data systems account
for tracking of changes
Accessibility to technical personnel
and suppliers of relevant information
5
6
Security and back up of the Data
7
Ensure business continuity via a
business continuity plan
Information
The design documentation will be the primary means by
which engineers are informed of key requirements and
design assumptions
Clearly defined criteria to develop and revise
documents, to limit documentation and ease access to
information in the future
The design documentation should be reviewed and
endorsed by relevant technical authorities to ensure
that the design basis remains aligned with Objectives
Allocated responsibilities and authorities to review and
issue documents, to withdraw and retain obsolete
documents
Arrangements to ensure that documentation is revised
and updated according to MoC section 3.5.6
All engineering activity undertaken throughout the
anticipated service life of an asset should properly
address AI considerations.
Engineers should be kept informed of AM related
decisions and plans, and factor those into modifications
and other forms of engineering activity to achieve good
alignment.
Particular areas of focus will be modification interfaces
between new and ageing equipment and where
inspection has shown some degradation to the existing
systems compared to design assumptions
Security of the data shall also be considered against
ransomware or any other virus; a backup of the
information and system shall be set up.
IT system can be hacked, asset partly damaged (e.g.
fire, explosion), key personnel can leave company. As a
result, significant knowledge and experience can be
lost. Operation can be disrupted for several weeks or
months with significant impact. Operator should have a
business continuity plan to address such threats.
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Table 3-19 Document& Data Storage System and Content
Item
#
1
Type of Data/Information
Description of Content
Information/data
system
Verkenningsfase
(Exploration phase and
Global Study Phase)
2
Haalbaarheidsfase
(Detailled Phase)
Data/information
storage system name,
version, server location
or archive location,
back-up solution, data
format, type of data
stored, description
3
Voorbereidingsfase
(Development Phase).
4
Realisatiefase (Drilling &
Construction Phase).
5.0
Productiefase work-over
(Production and Workover Phase).
Asset Management
Documentation, plan and changes, including
Project management and administration
document (doc control, Project control, Minute
of meeting etc.
Documentation, plan and changes, including
Project management and administration
document (doc control, Project control, Minute
of meeting etc.
Documentation, plan and changes, including
Project management and administration
document (doc control, Project control, Minute
of meeting etc.
Documentation, plan, equipment specification,
user manuals and changes, including Project
management and administration document
(Doc control, Project control, Minute of meeting
etc.
Documentation for operation, procedures,
reporting to authorities, Integrity planning and
strategies
5.1
5.2
Operation
Documentation
5.3
5.4
5.5
Inspection Data
Inspection Monitoring
Maintenance Data
6
Abandonneren
(Abandonment).
KPI
7
Document: Minute of meeting, Emails,
Contract, Bid and Offers, Invoice
recommendation or action internally and
externally. Ensure that know-how and
information is documented for business
continuity
Database and documents register of
procedures, analysis report, supplier
documentation for equipment, etc.
Minute of meeting
Visual inspection, record, analysis and results
Data monitored. See also KPI section
Predictive and corrective maintenance records
A data collection system shall be in place to
perform maintenance risk assessment and
track maintenance performed e.g.
Computerized Maintenance Management
System CMMS
Documentation and plan for abandonment and
cessation of activity
The organisation shall retain appropriate
documented information as evidence of the
results of monitoring, measurement, analysis
and evaluation.
8
Management of Change
Register
Changes for all phases in terms of design
basis, engineering, operation conditions etc.
9
Incident Associated Root
Cause and Investigation
Register
Incidents for all phase and associated
investigation
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Table 3-20 Typical Master Document Register Content
Document type
Document
title
Procedure, Technical
note, Minute of meeting
Procedure
operation/maintenance ,
inspection , Monitoring,
etc.
Doc. number
Revision
Status
As per Numbering procedure, i.e.
Categorised by equipment, by
system, by supplier or other
relevant categorisation approach
As per
Numbering
procedure
Active,
superseded,
draft, etc.
Performance Evaluation
Asset performance shall be measured, analysed and evaluated. The KPI provides the basis
to review effectiveness of the asset management system and process and ultimately the
adjustment of mitigation and / or monitoring activities. KPI’s are often used to give a high
level status of an asset when measured against defined criteria.
A set of performance/target level of service measures should be developed to monitor the
effectiveness of implementation of the Asset Management. A minimum list of KPI is listed in
section 3.7.3; some of them are only relevant if equipment is part of the asset. Target and
acceptance criteria are to be defined for each asset.
Monitoring, Audit & Review
Operators should have monitoring, audit and review arrangements in place. This is to
ensure that the AMP is delivering according to objectives and performance. The audits
should be conducted by both internal and external parties.
Audits focus on procedural compliance with respect to objectives, policies and requirement
by stakeholders. Audit plans and procedures shall be developed and maintained by the
Asset Team.
Audit records should be kept and resulting actions should be added to the Action
Management systems to ensure they are tracked, managed, and suitably closed out.
Table 3-21 Minimum Audit and Review Plan
Item #
1
2
3
4
Description
Recommended minimum
frequency
Review and Audit of AMP effectiveness and
compliance
Review and Audit of Inspection, Monitoring,
Testing and Maintenance plan, records and
execution
Review and Audit of Operation and integrity
processes and procedure
Review and Audit of suppliers
Once a year during Operation,
Once per project phase
Once a year, Twice yearly for records
Once a year
Twice for key suppliers during project
duration; every year for supplier involved
in Operation
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3.6
Reliability Studies
Reliability Prior to Operation/Production
From Exploration until Preparation phase, component systems shall be designed for
reliability, meaning the following principles should be applied: Functional clarity, Simplicity
(minimum parts to provide function), No weak components and remove common cause
failures, Robustness and Materials selection to avoid degradation processes
A FMECA for components and systems is recommended to address reliability and integrity
in design and also to establish Asset Integrity & Maintenance program and associated RBI
and RBM.

FMECA enables Designer and Operators to identify and treat failures that can be
mitigated through design.

Remaining failures will be treated during operation and followed through RBI or
RBM.
It is recommended that if a component/system is ranked as critical for operations during the
risk assessment phase, that testing and evidence of reliability are required from the
Supplier. Reliability of components can be demonstrated by suppliers via field experience
data or testing data.
Reliability Data Collection during Operation/Production
Reliability data related to Equipment’s/Components shall be kept by each Geothermal
Operator. It is recommended that Operator should anonymize and share these data on a
regular basis through a specific Forum/Network.
The data to be collected as a minimum are as per Table 3-22 for each component.
Table 3-22 Reliability Data Collection
Component
Name and tag
Operation time in
service of Components
(hrs)
Non production time
(hrs)
Cumulated
Maintenance time (hrs)
From start to last update of
the data in days
Number of
failures
Number of
Maintenance
order
Failure type
Number of failures during time
in service
Short description
of failure types list
: corrosion,
mechanical
failure, etc.
Failure description
Repair time
Downtime
Describe if failure occur during
normal or abnormal operation,
describe failure mode, failure
cause, failure effect, failure
criticality n term of safety or
production
Only time to repair.
Time from failure to restart;
include supply of part time,
failure investigation, repair
time, time for re-testing and
commissioning.
Number of Maintenance tasks
during Operation
Any shutdown time during
production/ operation
Cumulated Maintenance
time during time in Service
in days
Reliability, Availability and Maintainability (RAM) Analysis
Geothermal plant Availability and Ability to produce is a critical parameter to achieve
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Production Assurance, i.e. Production target toward end-user(s), i.e. minimum, and max
flow rate or number of production days due to planned maintenance/ shutdown (e.g.
300days production yearly).
However, each Geothermal Asset operates under different Business Model/Contract Terms
& Conditions between Operator and end users. A RAM analysis is recommended:
-
Whenever no Terms & Conditions have been agreed between Operator and
Users; e.g. operator and energy buyer is the same company, Geothermal asset
is own by a group of buyer, etc.) and,
-
User’s requiring a production delivery target (flowrate, temperature,
pressure; etc.)
Reliability is the probability of survival after a unit/system operates for a certain period of
time (e.g. a unit has a 95% probability of survival after 8000 hours). Reliability defines the
failure frequency and determines the uptime patterns. Maintainability describes how soon
the unit/system can be repaired, which determines the downtime patterns. Availability is the
percentage of uptime over the time horizon, and is determined by reliability and
maintainability.
The Reliability and Availability is started by defining the methodology to achieve targets at
concept. That includes designing for reliability. The RAM model is used to demonstrate the
target when design is completed. Reliability Data collected from generic database or from
field data are used in the RAM model.
The goal is mainly to be able to identify cost life cycle impact (CAPEX versus OPEX) of
selected technology, material, Process, need for Spares and Operation philosophy
(shutdowns, maintenance requirements, and retention of spares, etc.) based on production
needs to achieve targets.
Figure 7 Illustration Production Assurance terms (ref./ 24)
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3.7
Technical Integrity Management
The section covers the following deliverable part of the AMP:

System description and Operational parameter;

Generic Threats and Risk assessment to Support RBI and RBM (see section
3.3.5.2)

The “what, how and when” related to Inspection/Monitoring/Testing & Maintenance
technical program; The Inspection tools are further detailed in Appendix D.

Indicative Inspection & Maintenance Frequencies

Long term & Inspection, Testing & Maintenance Frequencies Historical Plan

The Periodic Review content , i.e. compliance and Asset Integrity assessment
This technical information section address LEGE Asset equipment, i.e. surface facilities for
primary loop and wells; the equipment listed and their associated inspection and
maintenance is not exhaustive as it depends on the asset design features and technical
design and operational challenges.
Geothermal System Description
A typical schematic overview of the geothermal asset is underlined in Figure 1. The
wellhead and separators are usually located outside the main/processing building. Note:
gas drying plant (only in some geothermal asset) is located inside of the main processing
building.
Note: additional facilities are sometimes used on some LEGE asset depending of operation
conditions and constraints. These are for instance biocide injection system in production
well, combined Heat and Power Generation (CHP) Boiler, Nitrogen Installation water tank
buffer to deliver temperature. These equipment’s are not discussed hereafter but it is
recommended to add them in the AMP.
The key surface equipment / components have the following functions:

Booster Pump is used to bring the hot degassed formation water to the desired
process pressure;

Filters are used to remove solids from formation water prior to the heat exchanger,
or to prevent particles resulting from heat exchanger degradation from entering the
injection pump;
o
Solids may be internal particles entrained in the rock matrix by hydrodynamic
forces or suspended particle precipitates of induced scale (carbonates,
heavy metal sulphides, silica) species.
o
Note that particles of infra-micrometric/colloidal sizes (diameters below 0.45
μm) are present in all waters sampled in the Netherlands (ref./ 10).
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
Heat exchanger, typically plate – type: where heat transfer takes place from primary
to secondary without mixing.

Injection Pumps, typically centrifugal type.

Water gas/separator: use of a degasser in a geothermal system aids in preventing
the formation of free gas and potential gas clogging further on.

Monitoring and chemical treatment equipment.
The typical geothermal facility has one or more production wells and injection well doublets.
The well is constructed with a conductor casing and surface casing which are usually
cemented to the surface. Liners may be installed to reach reservoir depth with a slotted
liner or wire wrapped screen over the reservoir section. Except for the final production liner
over the reservoir, all liners are cemented from shoe to the liner hanger assembly.
The production well is completed with a tubing and downhole pump, typically an electrical
submersible pump (ESP), with a simple wellhead and Christmas tree assembly of valves.
The tubing and casing materials are carbon and low alloy steel in all existing wells. The
typical injection well is essentially similar but without the downhole pump. The Electrical
Submersible Pump (ESP) consist of a multistage down hole centrifugal pump, a down hole
motor, a seal and a cable going all the way to surface. A variable speed drive can be used
to regulate the flow rate.
Each Production and injection well (i.e. doublet) and Christmas tree shall be operated and
maintained according to design. When a potential defect is identified, additional monitoring
or remedial work required to maintain the well condition shall be planned and carried out as
soon as practicable, depending on the nature and the assessed risk resulting from that
defect. Monitoring shall continue at an appropriate frequency to allow for timely
identification of any change in well condition, until the defect is remedied.
Figure 8 Diagram of Typical Production Low Enthalpy Dutch Geothermal Well
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Design Information Per Equipment
Key Design Information which will be useful for day to day operation shall be collected and
structured in the AMP as per Table 3-23. The information shall be up to date and reflect any
changes and modification occurring after original design & construction as per requirement
3.5.6.
Table 3-23 Design data per equipment
Equipment
Description
Value and units
Name of equipment
and associated
equipment
Information on key Design Parameter, such as Pressure &
temperature, fluid compatibility, voltage, material, geometry &
length, etc.
In addition key Suppliers information shall be added for the
safety and the integrity of the systems
Data itself or reference
to database or
document
Table 3-24 Typical Design Data For Well
Information
Value
Information
Value
Validation date
Well Schematic Attached
Well name
Wellhead and Xmas tree rating, dimension, service trim
Well Type
(Function)
Identify any leaking or failed barrier components
Reservoir
name
Additional Notes:
Original
Completion
date
Any limitation on acceptable kill and completion fluids?
Latest
Completion
date
Any special monitoring requirements?
Well design
Life
Any other comments?
Monitoring Operation Data and Technical and Non-techncial Performance Indicators
Monitoring of Operational parameters and following up the trends of Performance Indicators
(PI) is a key activity of the geothermal Integrity systems. Monitoring can take place through
sensors in the primary process streams, or in bypasses and / or subsurface. Monitoring and
inspection provide essential information on condition and can be continuous or at regular
intervals. It also gives advance warning of possible problems to avoid unexpected failures
and establish relations between operating parameters and threat behaviour. Monitoring
confirms the effectiveness of the mitigation measures and informs the planning of
inspection and maintenance programmes.
The Performance Indicator for LEGE Well and surface facility shall be monitored. PI for
reservoir and well are addressed in Table 3-25. Surface and general additives monitoring,
physical parameter monitoring and non-technical KI are addressed in Table 3-26.
Note that performance indicator and monitoring of parameters shall be adjusted as per Risk
Assessment, i.e. added or removed.
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Table 3-25 Production and Injection Well Integrity PI
Performance Indicator description
Target / Acceptance criteria &
Anomaly Limits
Operational Limits
(enter value or NA)
Min / Normal/ Max
Maximum Injection Pressure (psi)
GWR (scf/bbl)
Reservoir Pressure (Bar)
Reservoir Temperature (C)
SITHP (Bar)
Maximum design production rate (m3/hr)
Maximum design injection rate (m3/hr)
ESP design rate (m3/hr)
Table 3-26 Production and Injection Surface Integrity Operating Window & Minimum KPI
Performance Indicator Description
Additives Monitoring
Corrosion inhibitor content
Corrosion inhibitor availability
H2S Scavenger (Residual H2S Concentration)
Scale inhibitor (continuous/intermittent)
Bactericide / Biocide (continuous/intermittent)
Fluid Parameter Monitoring
Iron Ion content
Oxygen Scavenger (Residual O2
concentration)
Fluid Additives
O2 in Water Injection (ppb Oxygen equivalent)
CO2 (mol% in gas phase)
H2S (ppm in gas phase)
Water Calcium (Ca) content
Water Sodium (Na) content
Water Chloride (Cl) content
Water pH Value
Bubble Point
Methane (CH4) mol%
Physical Parameters Monitoring
Gas/water Ratio
Gas production
Injection pressure
Injection temperature
Production Pressure
Production temperature
Production Flow
Electricity consumption per Phase
Degasser pressure
Degasser, Flow rate
Water/Oil/Gas Separator, pressure
Acceptance Criteria & Anomaly Limits
To be defined as per asset design, i.e. the following shall be
defined for each KPI whenever possible.
1) Upper Safe Design limit
2) Upper Safe Operating limit
3) Upper Normal Operating limit
4) Normal Operating Limit
5) Lower Normal Operating limit
6) Lower Safe Operating limit
7) Lower Safe Design limit
Note that beyond 1) or below 6) equipment will operate with
Design Margin / known safe then uncertain operating
conditions.
Between
zone
2/3 and 5/6, this is called the Troubleshooting
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Performance Indicator Description
Water/Oil/Gas Separator, Temperature
Usage of Gas - Preferred option - WKK
(capacity)
Usage of Gas - Alternative option - Heating
(capacity)
Usage of Gas - Alternative option - Flare
(capacity)
Heat Exchanger, Flow Capacity
Heat Exchanger, Temperature In
Heat Exchanger, Temperature Out
Non-technical PI
Number of Audit
Maintenance back log
Corrective maintenance
Shutdown
Non Conformances
Training
Inspection back log
Acceptance Criteria & Anomaly Limits
Audit performed during the year
Maintenance not done as per plan
Per equipment per year
Number of shutdown
Non Conformance trends
Training completed versus training plan
Inspection not done as per plan activities
Generic Threats & Risk Assessment
This section presents Risk Assessment of relevant system Integrity Threats/Risk for LEGE
System. Table 3 -27 provides high level list of Threats to be used to assess the LEGE
asset.
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Table 3-27 Overall Geothermal Asset System Threats
3.7.4.1 Well Specific
Well Integrity (WI) can be defined as the ability of the well(s) to perform its required function
effectively and efficiently whilst protecting Health, Safety and the Environment.
Well Integrity Management encompasses the physical condition of the well(s) as well as the
necessary organization and activities needed to avoid the possibility of failure, which
potentially can result in serious incidents.
Risk Assessment
The WG Corrosion Review and Materials Selection for Geothermal Wells report (ref./ 9)
summarises the most common forms of corrosion and metallurgical degradation
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mechanisms that are potential threats applicable to geothermal wells in the Netherlands.
The Well & Xmas tree risks are driven by corrosion and mechanical stresses. For Instance,
Corrosion can impact ESP (bearing/sleeves) and steel part of the well. When it comes to
material degradation threat, hardening versus corrosion for ESP or tubing is typical issue of
the Material selection phase (ref./ 40).
CO2 is the principal corrodent in many geothermal reservoir fluids. A wide range of CO2
content is possible in any geothermal wells, but probably relatively high, i.e. 5 – 50 mol% in
the gas phase (ref./ 9). Potential “hot-spots” for CO2 corrosion in the well system include:

Pump, pump inlet & outlet in producers;

Perforations and sand screens;

Below (upstream) of corrosion inhibitor injection point in producers (if applicable);

Wellhead and tree (due to bends, flow restrictions);
When the geothermal fluid is brought to the surface and the temperature, pressure and
chemical properties change, the potential for deposition of scale on the casing walls and
within the heat exchanger and topsides facilities exists. Scale can precipitate and coat the
surfaces of plant components which can cause blocking of flow and reduction of heat
transfer capability. Studies (ref./ 11) show that this is the primary suspected cause of
severe injectivity decline on several injector wells.
H2S is not currently present in Dutch geothermal assets (ref./ 9), the potential for the future
presence of H2S should be considered and not be ruled out from Risk Assessment.
High quantities of particles in the geothermal loop as a result of degassing (if any) of the
water, which leads for instance to the precipitation of carbonates.
Review of other LEGE asset operational data and fluid include threats such as presence of
lead and erosion of the systems due to particles cannot be excluded. On some occasions,
scale removal and disposal methods extend the uptime however it may impact operational
cost (e.g. turbine washing).
Radioactivity levels (see LSA norm) are due to be monitored and baseline must be
established to measure evolution. The threat is mandatory by the law to be monitored.
The risk of cement degradation or bad cement may have large consequences whether
pollution of an aquifer or the presence of a gas pocket is identified.
Mechanically, the Risk of a stuck tool is possible and side track is not uncommon while
drilling.
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Table 3-28 Well Threat Risk Assessment
Threats/Risk
Mitigation
Material degradation;
Material yield
Corrosion program , Calliper inspection to assess deformation
Seal fails
Material selection , stop process fluid in seal
Design at Well construction phase
Component mechanical
stress
Cement degradation
Log and proper cementing job
Corrosion - internal &
external
Injection tubing 50m deeper than the free level in the well
Injection of N2 in well annuli to avoid air
Test water each month to detect trend
Scale & deposit
Stuck Tool
Drilling plan and corrective action
Material threats
Risk mitigation related to annuli behaviour,
Well barriers for drilling and workover operations,
Barriers on completed wells, or
Periodical tests/maintenance of surface wellhead/Xmas tree valves and subsurface
safety valves should be addressed
Operational risks

Pressure and temperature are important parameters for all equipment. If brine
boils, releasing gaseous water, then there is a risk of deposition of salt, eventually
causing blockages. If the temperature is lower than the solubility equilibrium, brine
can deposit its salt and cause solid accumulation in low temperature parts. This
can be critical depending on type of process and design (ref./ 10).

Low pumping efficiencies. Optimisation of pumping system design and operation
should be a focus in order to boost efficiencies and control OPEX costs;
3.7.4.2 Surface
Corrosion Risk Assessment
The surface facilities are continuous with the wells; CO2 is the main corrosive species and
forms of CO2 corrosion are the major internal corrosion threat in the surface facilities.
Due to the nature of the surface equipment, preferential weld corrosion and galvanic
corrosion are both more significant than downhole. Enhanced corrosion due to flow
conditions is possible at several locations. The process piping, pumps and valves are
subject to similar external damage mechanisms.
Externally, the systems operate in the temperature range where, if insulated, corrosion
under insulation is a significant threat.
Geothermal waters are often highly saline, and even small leaks will create salt deposits on
the external of equipment. Combined with the temperature, this creates potential conditions
for pitting corrosion and/or chloride stress corrosion cracking of austenitic stainless steels.
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This is particularly an issue with plate heat exchangers due to the thin plate thickness and
the greater potential for leaks. The same situation applies when stainless steel equipment is
opened, for example at filter changes.
Scaling is a threat, especially after separators, and scale could affect the heat exchangers
and filters operation in particular.
Mechanical Risk Assessment
Failures may occur as a result of surface breaking cracks from a pre-existing defect or
incorrect fastener preload on steel part such as piping, valves. There are different causes of
thermal fatigue failure, for instance, general temperature cycling or localised drips of
atmospheric condensation onto hot piping.
This probability is expected to be low (equipment within the buildings, low fluid temperature
variation).
Valves are subject to the same threats as the process piping. However the underlying
cause of the valve problems can be divided into two main groups. The first group is when
there is a design fault or problem with the valve itself. The second group is when the valve
problem is due to ‘other causes’ or to progressive deterioration, such as incorrectly
installed, incorrectly specified, operating conditions have changed from the original
conditions, or a faulty operating procedure.
GRE requires more frequent piping support than steel piping. It has much less ductility than
carbon steel, and therefore is much less tolerant of poor fit-up and of thermal strains that
would be no issue with steel construction.
Separators mechanical threats are expected to be limited with suitable inspection and
design.
Typical heat exchanger risk are the accumulation of debris i.e. foreign material in plate can
lead to under deposit corrosion, leaks/cracks, leaks/seeps at flanged joints. Additional
threats may impact the heat function delivery, i.e. the production availability, without
necessary damage to the equipment. The failure of heat exchange is highly probable on
most of the current LEGE installation.
Pump casing rupture due to thermal fatigue due to frequent restarts, low ambient
temperature, high fluid temperature, insulation, operational procedures has been reported.
Only few vibration cases have been reported on Netherlands LEGE asset. Motor vibration
can occur due to misalignment of pumps (Booster and Injection) and / or dampers. These
can induce vibration in piping/welds inducing leaks. Gas content in fluid may also induce
cavitation and erosion of impellers of pumps.
Process fluid in seal may reduce lubrication, increased temperature of the seal, and
generate fatigue. Probability of fluid in seal is highly probable (several report of white salt
precipitation as a result of fluid leak at seals).
Finally, the filters are a key element of the LEGE Asset process as the debris can lead to
the cause of other threats to the system such as accumulation of debris leading to under
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deposit corrosion, leaks/cracks or leaks at the joints. Maintenance and inspection of the
filters combined with lessons learned should limit the failure of other part of the systems
due to debris.
Table 3-29 contains Threats which shall be reviewed as per above Risk Assessment of
LEGE Asset during RBI and RBM. It also proposes mitigation options than can be used in
RBI and RBM.
Table 3-29 Threats, Risk Assessment and Mitigation for Surface Equipment
Equipment
Threats
Mitigation Options
Corrosion
All piping and
Scaling
Scale inhibitor;
equipment
Piping
pH control (controlling outgassing of CO2)
CO2 Corrosion
Steel piping with corrosion allowance +
(including preferential weld corrosion, flow assisted
inhibitor treatment
corrosion)
Or GRE piping
Galvanic corrosion (to major stainless steel
Isolation joints or flange isolation kits at key
equipment)
locations
Or GRE piping ( excellent material to handle
corrosive saline water and eliminates the major
internal and external corrosion threats
Atmospheric corrosion
External coating; inspection and maintenance
Corrosion under insulation
regime
Or GRE piping
Dead Leg Corrosion in piping
Remove /reduce during design. Planned
access to inspect
Pipe Supports
Corrosion caused by the common combination of
Preventive Maintenance
water and dirt accumulating in the crevice between
the pipe and support
All stainless
Internal pitting and/or Cl-SCC
steel equipment
Operating procedures for shut-downs to avoid
exposure to hot saline water + oxygen (air)
Vessels
CO2 corrosion
(separator ,
External coating system breakdown
Stainless steel ( minimum 316 / 316L)
filters)
Pumps
CO2 corrosion (flow assisted corrosion)¨
Stainless steel ( minimum 316 / 316L)
Corrosion / erosion
Heat
CO2 Corrosion
Stainless steel
External pitting and/or Cl-SCC
Higher grade stainless steel, e.g. 22Cr duplex
External coating system breakdown and corrosion
(e.g. UNS S31803), or 6Mo stainless steel
(Plate and nozzles),
(e.g. UNS S31254)
Flange corrosion
Design details to minimise leaks
CO2 Corrosion
Stainless steel (316 / 316L minimum)
Crevice corrosion
Avoid threaded small bore connections in
exchangers
(plate type)
Instrumentation
tubing and
equipment
carbon steel. Use welded or flange
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Equipment
Threats
Mitigation Options
connections for preference.
Chemical
Chemicals (corrosion inhibitor, scale inhibitor,
Stainless steel (316 / 316L) and non-metallic
treatment
biocide)
are standard for cleanness. Check Supplier’s
equipment
recommendations.
Note that neat chemicals (including corrosion
inhibitors) can be corrosive to carbon steel.
Filters
The following are typical damage mechanisms
Inspection and preventive maintenance
applying to Filters:
 Internal coating breakdown.
 Chloride Stress Corrosion Cracking.
 Wet CO2 Corrosion.
 Crevice Corrosion.
 Erosion Corrosion.
 External coating system breakdown.
 Corrosion under insulation as a result of operating
and environmental conditions.
 Leaks at the joints.
 Microbiologically Induced Corrosion (MIC).
Surface valves
Atmospheric / External corrosion of uninsulated
Inspection and preventive maintenance
All piping and
equipment
carbon steel
Mechanical Fatigue - internal or external cracking of
cyclically-stressed components. Failure may occur as
a result of surface breaking cracks from a preexisting defect or incorrect fastener preload etc.
Monitor and protect system from thermal,
vibration, and any impact

Thermal Fatigue - caused by general
temperature cycling or localised drips of
atmospheric condensation onto hot piping,

Vibration induced Fatigue,

Mechanical hazard - pipe hit by car / truck, etc.,
install appropriate mechanical protection on
piping,
Mechanical
All piping and
equipment
Mechanical Fatigue - internal or external cracking of
cyclically-stressed components : Thermal Fatigue
and Vibration induced
Mitigate Mechanical hazard - pipe hit by car /
truck, etc., install appropriate mechanical
protection on piping,
GRE piping
Ductility and sensitive Thermal strains
The piping layout and supports should be
designed with these characteristics in mind.
Separators will
be treated as
large pressure
vessels
Heat Exchanger

Accumulation of debris i.e. foreign material,

Leaks/cracks,

Structural support failure,

Leaks at the joints.

Blockage of the tubes, Flow Blockage

Leaks/cracks

Leaks/seeps at flanged joints,

External tube fretting
Filter debris, inspection and set up proper
support , verify
Daily regulation, repair procedure for failure
mode, select equipment with high reliability
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Equipment
Surface valves
Pumps (Booster
and Injection)
Filters
Threats
Mitigation Options

Loss of thermal power,

Closed loop fluid losses,

Contamination of "clean fluid" (i.e. secondary
loop),

External tube fouling,

Reduction of U (heat transfer coefficient) value.
Typical damage mechanisms apply to valves:

Erosion and Corrosion-Erosion - occurs
when there are high fluid flow rates, sands
or other solids present. Commonly found in
sand washing operations.

Packing damage / loosening - valves leak
through valve packing gland, damage to the
gland packing area will result, requiring
valve to be replaced or repaired.

Mechanical Fatigue - internal or external
cracking of cyclically-stressed components.
Surface breaking crack from external
surface or from a pre-existing defect

Thermal Fatigue: caused by general
temperature cycling or localised drips onto
hot valve casings.
Key damage mechanisms affecting the pumps:

Vibration

Erosion

Gas content in water

Fatigue

Process fluid in seal

Pump casing rupture due to hermal fatigue.
Early Damage of filters
Filtering of debris,
use the Quench,
monitor potential vibration and limit operation
condition if need
Avoid frequent restarts (usually LEGE practice
Support and operation procedure to avid
thermal change and vibration
Remove debris on regularly basis
Christmas-tree and Well: Inspection, Testing & Maintenance Program
3.7.5.1 Inspection and Test
Inspection, Monitoring of operational parameters optimises well management and gives
cost-benefits by proactively identifying issues that can be addressed before they become
serious. A well monitoring and inspection plan shall be established and maintained for both
the downhole and surface components of all wells, taking into account subsurface
conditions, well operating range; well history, changes observed in other wells in the field,
ground subsidence, and well configuration.
The well monitoring plan shall specify the inspection and monitoring frequency for both
downhole and surface components. In addition to the well monitoring plan, each wellhead
shall have a documented annual inspection. Typical information to be recorded are
wellhead pressure, well status (for example, shut-in, bleed, production, injection), operating
condition and leakage of wellhead valves, condition of protective paint systems, condition of
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the anchor casing, condition of the site and cellar drainage or changes in the vertical
position of the wellhead measured relative to other casings. Compilation and upkeep of
detailed records of the above activities in a chronological log shall be kept.
Inspection and Monitoring frequencies will differ from components to component and
integrity level resulting from risk assessment (see section 3.3.5). Recommendation and
indicative frequencies for various threats and equipment items are:

Regular inspection and testing of Xmas Trees / valves to provide confirmation of the
integrity of the outer envelope of the well.

Regular scheduled collection and analysis of data to be used in predictive model
whenever possible to re-define frequencies (e.g. corrosion modelling).

Scheduled (6 or 12 months) sampling of the gas and water or any other determined
frequency based on risk assessment.

Install corrosion coupons of same material as the casing and determine corrosion
rates at set intervals.

Pressure and Temperature recording for producer and injector reinjection wells.

Recovered tubing to be inspected after retrieval to check for corrosion/scaling etc.

Wall thickness or ID measurement of the casing during any well interventions.

Regular in service valve integrity testing should be carried out on all wellhead /
Xmas tree valves at up to yearly intervals.

Frequent inspection of wellheads can give a first indication of potential corrosion
problems in the system as a whole, and an indirect pointer to problems in the well.

Inspection of the Producer and Injection well is practical; a multi-finger calliper tool
can be run in the casing string while the tubing is out. The tubing can be inspected
visually at the surface. A suggested inspection interval is approximately 5-yearly
(ref./ 9). Longer intervals may be appropriate for systems with very low CO 2 and
very mildly corrosive conditions. The interval can be adjusted based on experience
or on any indication of corrosion problems from the monitoring data.

Ultrasonic inspection of wellheads at specific datum locations is recommended for
carbon / low alloy wellheads on an annual basis.
Inspection initially on an annual basis is suggested due to the criticality of the wellheads.
This frequency can be modified based on experience using a risk-based approach.
Basic Corrosion monitoring program is described in Table 3-31.
3.7.5.2 Maintenance
The wellhead is considered to be a barrier together with the production casing, the tubing
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hanger seals in the wellhead and the Xmas tree. The integrity of these barriers shall be
maintained at all times by the following means:

Weekly routine visual inspection to detect any signs of leaks or damage.

Routine valve function and pressure testing where feasible.

Routine maintenance (lubrication).

Any valve, which fails to meet the defined test requirements, must be replaced or
repaired as soon as operationally convenient.

Maintenance and testing frequency of the wellhead should reflect changes in the
equipment condition.

Although the recommended frequency is yearly, Operators can carry out a risk
assessment to justify deferring the maintenance if the valves have shown no failures
over a certain period of time.
Testing and maintenance should be carried out in accordance with Manufacturer
instructions (ref./ 9 ).
Surface Facilities : Inspection, Testing & Maintenance Program
3.7.6.1 Inspection and Test
Corrosion Monitoring basic program is discussed in section 3.7.5.1 as per ref./ 9.
Piping
Piping inspection may be divided into two categories:
External Examination: General Visual Examination of all features and Close Visual
Inspection (CVI) of accessible features will be carried out. The inspection will include pipe
supports and hangers and the integrity of flanged connections (for evidence of flange face
corrosion and nut/bolt tightness and deterioration). NDE of selected features will also be
undertaken based on the respective damage mechanism(s) for the section of piping. In
instances where there is deemed to be a threat from discrete random internal damage,
pipework screening tools should be used as large sections may be screened quickly and
where features are detected, these may be sized using more appropriate methods (such as
UT).
Internal Examination (Invasive): CVI of flanges and visible sections of pipe bore will be
carried out. A boroscope may be used to extend the coverage of inspection as appropriate.
NDE of selected pipe bore may be carried out in order to measure remaining wall
thicknesses and to determine the extent of any corrosion which may have occurred. Where
NDE is deployed, specific features such as bends, elbows, tees and welds should be
included as these areas may potentially be more vulnerable especially in high/turbulent flow
conditions.
Inspection Techniques and Frequency
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Pipework inspections should be carried out using the most appropriate inspection
technique(s) that will provide the highest likelihood of detection and quantification of the
prevailing mechanism(s) of deterioration; there are a variety of inspection methods that are
available for use however typical inspections would be expected to include any number of
the following: visual examination, borescope, UT, MPI, DPI or Radiography. The frequency
of inspections should be based on the assessed risk profile of the pipework items or
pipework systems that are in use.
Water & Gas Separator
The inspection of the separator pressure vessel will be defined generally by the RBI and
specifically by the written scheme of examination of the vessel. Particular attention will be
given to following areas: External Shell / Dome Ends, Shell Internals, Nozzles and joint
faces, Bridles, Welds, Bolting, Mounting, Paint system, Insulation and Vortex Breaker.
The inspection may comprise general and/or close visual inspection supplemented with
NDE as appropriate, although the choice of NDE method will depend on the failure threat(s)
that are prevalent in the specific system. A typical risk based scheme would comprise
invasive and non-invasive inspection cycles (where an invasive inspection would warrant
the removal of the separator vessel from service and the breaking of containment to effect
the inspection; non-invasive inspections can be performed whilst the separator is on-line
and relies on the deployment of NDE). The inspection intervals will be dependent upon
prevailing risk profile.
A typical (non-comprehensive) list of test, inspection and monitoring includes:

Corrosion probes, periodic internal inspections,

Monitoring : pressure and level transmitters
Heat Exchanger
Internal Inspection is used to establish the suitability of a heat exchanger for continued
operation. The internal inspection may involve a complete visual inspection, supplemented
by NDE techniques, on all components. Special inspection techniques may be used to
evaluate the mechanical integrity of this type of equipment, specifically the condition of the
plate.

IRIS (Internal Rotary Inspection System)

ET (Eddy Current Testing)

RFT (Remote Field Testing)

MFL (Magnetic Field Leakage)

Callipers

Temperature monitoring and control, periodic inspection (Fouling)
External Inspection – The inspection will be performed on the external surface to determine
if leaks, mechanical or structural damage is present. Generally, much of the inspection will
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be done while the heat exchanger is in service.
A typical risk based scheme would comprise of invasive and non-invasive inspection cycles
(where the terms invasive and non-invasive inspections were defined above). The
inspection intervals will be dependent upon prevailing risk profile. Evaluation of all
inspection data will be performed in strict conformance with the latest editions of API-510
Code - “Pressure Vessel Inspection, Repair, Alteration, and Reconstruction” and API RP579 “Fitness for Service”.
Valves on Surface
API 598 provides guidance on inspection and testing of the valves however this is written
for new valves only. There is no specific guidance available for integrity management of
operating valves.
The general practice for process valve integrity management is to set an
inspection/overhaul frequency based on risk; guidance from the OEM should also be
considered, if available. A typical inspection/overhaul will involve the removal from service,
typically during a plant shutdown or process train outage, and the stripping down/
dismantling of the valve(s) in a workshop environment.
Visual inspection and NDE is carried out on the critical components of the valve to look for
any signs of wear or deterioration. The design clearances are recorded during dismantling
and rebuilding of the valve on a workshop bench. If the recorded clearances are within the
tolerance specified by the manufacturer then the valve is rebuilt and put back in to service.
Should there be any component with significant deterioration or metal loss, the decision is
made to replace the component or replace the whole valve.
Alternatively, valves are removed from the process plant and sent to OEM for overhaul and
refurbishment. The inspection of a valve and its components may be carried out using
visual examination, borescope, UT, MPI, DPI or radiography to establish the condition. The
choice of specific technique will be based on the type of suspected damage mechanism
and may also be restricted by the access limitations. The inspection intervals will be
dependent upon prevailing risk profile.
Pumps (Booster and Injection)
The failure modes in pumps cannot all be measured directly without taking the pump out of
service and therefore secondary effects often need to be monitored instead. Once again,
operational experience can provide a useful guide to the early symptoms of failure modes.
This is an important part of Condition Based Monitoring (CBM) and it is important to have
processes in place that ensure small changes can be tracked and used to identify potential
issues in the future. Some of the most useful parameters that can be monitored on a pump
are detailed below.

Vibration e.g. check vibration of pump body, Thermography

Ultrasound, Pressure/Flow, Current, Contamination
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
Visual
o
Leaks (product, oil, grease), Contamination sources (dirt),
o
Loose components Corrosion, Effectiveness of instrumentation, Oil level,
o
Abnormal noises, Change in environment, Condition of bolts
ISO10816 Part 7 provides 4 vibration level zones specifically for roto-dynamic pumps,
according to the associated risk of continuous operation.
Filters
The inspection techniques will be similar to piping. Particular attention should be given to
the following areas.

External Shell / Dome Ends, Shell Internals, Nozzles and joint faces

Welds, Bolting, Mounting, Paint system, Insulation.
The inspection shall comprise Visual General Visual Inspection (GVI), Close Visual
Inspection (CVI), supplemented with NDE depending on the failure threat assessment as
deemed necessary. A typical risk based scheme would comprise invasive and non-invasive
inspections. The inspection intervals will be dependent upon prevailing risk profile.
3.7.6.2 Maintenance
Piping
Piping systems and pipework can fail in a number of ways. The most commonly
experienced failures are associated with either internal or external corrosion of the pipe
wall. Other failures may involve alternate metal loss mechanisms, such as erosion, fretting
or gouging. Repairs may be effected on-line using clamps or composite reinforcement
‘wrap’ systems; or alternatively may involve the replacement of the affected section of
pipework. There are a number of proprietary repair components/systems in existence,
involving both metallic and composite materials, but these systems may have certain
limitations regarding their applicability against a range of repair scenarios. There are three
main repair scenarios,

Pipe subject to external metal loss (caused by corrosion or mechanical damage),

Pipe subject to internal
erosion/corrosion), and

Pipe components that are leaking.
metal
loss
(caused
by
corrosion,
erosion
or
In addition, the extent of the deterioration or damage (i.e. localised or extensive) will also be
considered when choosing the repair methods and repair components.
Usually the most economical repair solution will involve the replacement of the damaged
section of pipework. This may be straight forward where existing flanged connections are
available to facilitate the replacement of a section of damaged pipework. Alternatively the
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repair could simply involve welding in place a replacement section of pipe. Other repair
methods are also available (e.g. clamp, “self-seal”).
For safety critical piping systems, the adopted repair philosophy will therefore be:

Suitable temporary repair (if feasible) until replacement can be carried out;

Permanent repair where replacement is not practical.
The guidelines above generally apply to the repair of carbon steel pipework. Other metallic
pipework, such as stainless steel, duplex stainless steel, copper, nickel etc., may present
other factors for consideration (e.g. weldability, surface treatment/preparation agents for
composite materials etc.), and may be considered on a case by case basis.
Water & Gas Separator
Maintenance of the separators is mainly related to inspection, and cleaning typically carried
out once a year apart from cycling level control valves, which have a tendency to stick.
Before any repairs are made to a vessel, the applicable codes and standards under which it
is rated will be considered to assure that the method of repair does not violate appropriate
code requirements. API 510 sets forth minimum petroleum and chemical process industry
repair requirements and is recognized by several jurisdictions as the proper code for repair
or alteration of pressure vessels.
If and where defects/anomalies are detected, they will be subject to Fitness for Service
(FFS) assessment in accordance with API 579-1/ASME FFS-1, Part 9. The source of the
problem requiring the repair will also be determined. Treating the source of the condition
causing damage will, in many cases, prevent future reoccurrence. The repair solution will
be dependent on the defect type and location on the vessel.
In the event that a temporary repair is being applied whilst the vessel is in operation (such
as in the installation of composite reinforcement wrap systems), there will be no
requirement for pressure testing, as the pressure containment envelope would not have
been breached. However, if the repairs warrant the removal of the vessel from service and
the breaking of containment, this shall require leak testing to be performed on completion of
the repairs (to 1.1 x design pressure). In the event that the repair solution requires welding
to be done on the vessel, this shall require a ‘strength test’ be performed on completion of
the works (to 1.5 x design pressure); in either case (i.e. leak testing or strength testing) this
shall be performed using treated water as the test medium (i.e. hydro-testing shall be used;
pneumatic testing is permissible but only providing the appropriate additional safety
measures are undertaken).
API 510 provides additional details on pressure test requirements. ASME PTB-2-2009 may
be referred to as an additional guide for lifecycle management of the pressure vessels.
Heat Exchanger
Before any repairs are made to a heat exchanger, the applicable codes and standards
under which it is to be rated will be considered to assure that the method of repair does not
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violate appropriate requirements. API 510 sets forth minimum petroleum and chemical
process industry repair requirements and is recognized by several jurisdictions as the
proper code for repair or alteration of pressure vessels.
If and where defects/anomalies are detected, they will be subject to Fitness for Service
(FFS) assessment in accordance with API 579-1/ASME FFS-1, Part 9. The source of the
problem requiring the repair will be determined. Treating the source of the condition causing
damage will, in many cases, prevent future reoccurrence. The repair solution will be
dependent on the defect type and location on the equipment. Repairs to the heat exchanger
bundles can fall into the following categories:
Minor Repairs:

Minor weld metal build-up of gasket surfaces and machining.

Minor welding

Replacing worn or damaged part.
These minor repairs would be relatively low cost if carried out during a planned
maintenance outage. Often minor damage is not repaired but is subject to periodic
monitoring in order to ensure that the damage does not progressively worsen to the extent
that it compromises the integrity of the heat exchanger.
In the event that a temporary repair is being affected whilst the vessel is in operation, there
will be no requirement for pressure testing, as the containment envelope would not have
been breached. However, if the repairs warrant the removal of the vessel from service and
the breaking of containment, this shall require leak testing be performed on completion of
the repairs (to 1.1 x design pressure).
In the event that the repair solution requires welding to be done on the vessel, this shall
require a ‘strength test’ be performed on completion of the works (to 1.5 x design pressure);
in either case (i.e. leak testing or strength testing) this shall be performed using treated
water as the test medium (i.e. hydro-testing shall be used; pneumatic testing is permissible
but only providing the appropriate additional safety measures are undertaken). Whereas, if
the type of temporary repair is to be carried out that requires a shut-down of vessel and
breaking of containment, then the pressure test requirements will apply and vessel will be
pressure tested to 1.1 x design pressure.
API 510 provides additional details on pressure test requirements. ASME PTB-2-2009 may
be referred to as an additional guide for lifecycle management of the pressure vessels.
Valves on Surface
Valves should be kept in good condition through routine greasing, cycling and function
testing in alignment with valve type and OEM recommendations. The valve packing glands
(where applicable) should be checked and repacked as necessary.
Pumps (Booster and Injection)
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The general practice for pump integrity management is to set an inspection/overhaul
frequency based on the advice from the manufacturer. The pump is removed from the plant
during a shut down and the individual components are dismantled in a workshop
environment.
Visual inspection and NDE is carried out on the critical components of the pump to look for
any signs of wear or deterioration. The design clearances are recorded during dismantle
and rebuild of the pump on a workshop bench. If the recorded clearances are within the
tolerance specified by the manufacturer then the pump is rebuilt and put back to service.
Should there be any component with significant deterioration or metal loss, the decision is
made to replace the component or replace the whole pump.
The inspection of the pump and its components may be carried out using visual
examination, borescope, UT, MPI, DPI or Radiography to establish the condition. The
choice of specific technique will be based on the type of suspected damage mechanism
and may also be restricted by the access limitations. A typical risk based scheme would
comprise invasive and non-invasive inspections. The inspection intervals will be dependent
upon prevailing risk profile.
Filters
If and where defects/anomalies are detected, they will be subject to FFS assessment in
accordance with API 579-1/ASME FFS-1, Part 9. It is important that the source of the
problem requiring the repair is determined. Treating the source of the condition causing
damage will, in many cases, prevent future problems. The repair solution will be dependent
on the defect type and location on the vessel.
In the event that a temporary repair is being affected whilst the vessel is in operation, there
will be no requirement for pressure testing, as the containment envelope would not have
been breached. However, if the repairs warrant the removal of the vessel from service and
the breaking of containment, this shall require leak testing be performed on completion of
the repairs (to 1.1 x design pressure). In the event that the repair solution requires welding
to be done on the vessel, this shall require a ‘strength test’ be performed on completion of
the works (to 1.5 x design pressure); in either case (i.e. leak testing or strength testing) this
shall be performed using treated water as the test medium (i.e. hydro-testing shall be used;
pneumatic testing is permissible but only providing the appropriate additional safety
measures are undertaken).
ASME PTB-2-2009 may be referred to as an additional guide for lifecycle management of
the pressure vessels.
Periodic review : Integrity Assessment and Analysis
The data monitored in section 3.7.3 are used to perform daily, monthly, yearly analysis of
the Asset to define its level of integrity, i.e. Integrity Assessment.
The Periodic Review shall provide a yearly overview of the Asset Integrity. It shall assess
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and discuss the following:


Compliance with AMP with:
o
Inspection, testing, monitoring & maintenance program requirements;
o
Business asset management system requirements (section 3.4).
Address as a minimum, the following assessment or analysis:
o
Corrosion assessments covering internal and external corrosion;
o
Scale formation assessment by means of fluid composition monitoring and
Well/tubing pressure monitoring;
o
Scaling Erosion assessment;
o
Mechanical assessments e.g. fatigue, cracks, displacement causing
overstress, third party damage causing extreme strains, etc.
o
Other Assessment (e.g. vibration or blockage).

Top 5 Risks and Threats

Recommendation for ITM&M program for the year to come and for the RBI and
RBM
Indicative Inspection, Testing & Maintenance Frequencies
The inspection intervals will be dependent upon prevailing risk profile and this will be
regularly reviewed and update as per the Integrity life Cycle process. Inspection intervals
depend on historical record, analysis of failure, reliability statistic or analysis, or any other
prediction model. Maintenance depends on supplier recommendation and historical record
based on RBM.
With regards to AMP, hereafter indicative Intervals/ Frequency are provided as guidance for
defining Long Term planning for Inspection, Testing and planning accounting for RBI and
RBM outcome (see 3.7.9).
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Table 3-30: Frequencies
Equipment
Inspection Frequency
Reference/
Source
DAGO Practice
Inspection
Separator
Pressure relieve
design
Piping & Valves
Booster Pump &
Injection Pump
Heat Exchanger
Filters
Producer and
Injection well
API 510 – May 2014
Max 12 months for GVI/CVI
Max one-half the remaining life of the
vessel or 10 years for thickness
measurement and on stream inspection
Max inspection intervals for pressurerelieving devices in typical process
services should not exceed:
a) 5 years for typical process services,
and
b) 10 years for clean (non-fouling) and
noncorrosive services.
12 months for GVI/CVI
Max 48 months for Maintenance
Depending
API 510 – May 2014
API 570 – February Wall thickness 2 time
2016
year
Routinely CVI (read gauges, leak,
Typical Manufacturer
vibration etc.)
specification
Maintenance monthly/annually/by hours of
service depending on parts
GVI
DAGO
Max 3 months for inspection/Maintenance
approximately 5-yearly
6 times per year
Daily check
Typical Manufacturer Every 4 time to take a
specification
sample
1 to 4 weeks
depending of filter
redundancy
arrangement
ref./ 9).
Testing
Xmas Trees /
valves
6 or 12 months
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Table 3-31 Basic Corrosion Monitoring Regime/Frequencies
Technique
Notes
Corrosion Monitoring
LPR corrosion probe
pH monitoring
At a convenient location in the surface piping or on a bypass loops. Ideally,
real-time connection to control room. Otherwise, manual reading or
download of data daily.
Acts as an alert for problems with the inhibition system.
Corrosion coupon
Process measurements
(pressure, flow rates ,
temperature)
At a convenient location in the surface piping. Typically retrieved 6-monthy.
Standard process measurements
Sampling
Inhibitor residuals (biocide
residual, scale inhibitor
residuals etc. if applicable)
Measure at commissioning of the system to set initial dose rates. Review at
6 or 12 monthly intervals.
Sampling point should be as far downstream as practical, e.g. at injection
wellhead.
For systems with Separator, measure the off-gas. May be by on-line
monitor or by sampling (e.g. 6-monthly). It is important that a consistent
sampling location and technique is used.
CO2
LEGE Asset Practice : monthly assessment
Water chemistry
Sampling and laboratory analysis , e.g. 6 or 12 monthly
(see Appendix D)
LEGE Asset Practice : monthly
Bacteriological sampling and
analysis
Only required as routine with lower salinity waters able to support microbial
activity.
Monitoring of Inhibition systems
Check level of chemical in the
storage tank
Record daily, confirms that inhibitor is being used, ensures re-supply on
time etc.
Pumps and equipment
operational
Check and record daily. On-line alerts may be used, but manual check
should still be made.
Chemical dose rate
Daily. Check versus target and record.
Adjust or re-set rate if necessary.
Note:
-
Reference (ref./ 18) provides practical information on data gathering such as
retaining samples of fluids and contaminants, taking pairs of water samples
upstream of the separator and at the injector wellhead, a pressurized sample
from the producer wellhead, etc.
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-
Note that data gathering should be designed to meet study/interpretation needs,
rather than studies having to adapt to whatever is delivered.
Long Term Historical & Planning : Inspection, Testing & Maintenance
Long term and Historical Inspection & Maintenance plan should be kept and maintained.
The document aims to provide an overview of past, present and future activities for each
equipment item. It also provides input to plan resources. Table 3-32 is a template showing
how the plan is built for piping systems. Information is provided in section 3.7.6 to build the
table for other equipment.
This plan is revised a minimum once a year during operation after the Assessment/
Analysis and Risk Assessment are performed (see 3.3.5.1). Indicative frequencies are
provided in section 3.7.8 to build the planning together with Risk Assessment, i.e. RBI and
RBM (as per section 3.3.5.2).
Table 3-32: Inspection & Maintenance Planning template
System
s
Component
or part
Description
Procedure
reference
M. 1
M. 2
Doc number
S
S
S
Inspection
M. 3 M. 4
M. 5
M. n
P
P
P
Inspection
Piping
All piping
flanges
As per
Assessment
findings
Piping section,
Wels, etc.
All piping
Corrosion
under Isolation
Piping
Internal
Piping
all
Flanges
General GVI
CVI
NDE
F
P
P
Internal
Examination
Wall thickness
NDE
Testing
Pressure
Maintenance
Painting
Seal
Note:

S: Done and successful; F: Done and failed; P: Planned. New Abbreviation to be
added as required.

Time line can be Month, Year, or Week depending on equipment. First two lines for
piping system are an example.

It is suggested to develop an Excel Spreadsheet to keep historical recording and
show planned activities.

Additional equipment to be added as per LEGE Asset.
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4.0
References
ref./ 1 DAGO WIM HAZID Report Final - 20-05812-001-16 –
ref./ 2 NZS 2403:2015 - Code of practice for deep geothermal wells
ref./ 3 NOGEPA, Industry Guideline No.50 Asset Integrity, revision 4.1 ; 31-001-2014
ref./ 4 EU Project REGEOCITIES; Best Practices related to regulation of Shallow
Geothermal Energy; viewed December 2013;
https://ec.europa.eu/energy/intelligent/projects/sites/ieeprojects/files/projects/documents/report_of_the_best_practices_related_to_regulation_of_s
ge_systems.pdf
ref./ 5 DNV RP F-116 Integrity management of submarine pipeline systems
ref./ 6 ISO 55000 - Asset Management - Overview, principles and terminology
ref./ 7 ISO 55001 - Asset Management - Requirements
ref./ 8 ISO 55002 - Asset Management - Guidelines
ref./ 9 DAGO, “Corrosion Review and Materials Selection for Geothermal Wells”; Wood
Group Intetech, June 2017; rev.03
ref./ 10 Report Assessment of Injectivity problems in Geothermal Greenhouses Heating
wells, funded by Kas als Energiebrom program, 5/01/2015
ref./ 11 Lead deposition in Geothermal Installations, TNO, 2014 R11416
ref./ 12 Alaref O. & Co.; Comprehensive Well integrity Solutions in Challenging
Environments using latest Technology innovations, 2016, OTC-26560-MS
ref./ 13 Drilling and Well Construction; Chapter 6, Geo-Heat Center viewed December
2016; http://www.oit.edu/docs/default-source/geoheat-centerdocuments/publications/geothermal-resources/tp65.pdf?sfvrsn=2
ref./ 14 Corrosion in Dutch Geothermal Systems, TNO 2015 R10160, 2016
ref./ 15 Review of Current State of the Geothermal Industry with a focus on The
Netherlands, August 2015, MSc Thesis
ref./ 16 Geothermal Investment Guide, project deliverable 3.4; Serjujuk M. & Co; 2013;
www.geolec.eu
ref./ 17 Technology cluster Forensic Engineering; Sponsors: Aardwarmte Vogelaer BV,
AMT International BV, Geopower Holding BV, V.o.f.; Geothermie De Lier, Nature’s Heat BV
TNO reference: 060.17160
ref./ 18 TNO 2012 R10719- BIA Geothermal – TNO Umbrella Report into the Causes and
Solutions to Poor Well Performance in Dutch Geothermal Projects -2012 October
ref./ 19 Chinedu I. Ossai, Brian Boswell*, Ian J. Davies; 2014; Sustainable asset integrity
management: Strategic imperatives for economic renewable energy generation; Renewable
Energy 67 ; p 143-152
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ref./ 20 Lichti K. & Co., 2013, The Application of Risk Based Assessment to Geothermal
Energy Plant, NACE international Corrosion Conference & Expo 2013, paper 2438
ref./ 21 John Finger J., Blankenship D., 2010, Handbook of Best Practices for Geothermal
Drilling, SAND2010-6048
ref./ 22 Loizzo M., Bois, A., Etcheverry P., Linn M.; 2014; An evidence-based Approach to
Well integrity Risk Management, SPE Annual Technical Conference and Exhibition, 27-29
October, Amsterdam, The Netherlands SPE- 170867
ref./ 23 BS EN ISO 17776:2002, Petroleum and natural gas industries. Offshore production
installations. Guidance on tools and techniques for hazard identification and risk
assessment, Edition February 2001.
ref./ 24 ISO 20815:2008, Petroleum, petrochemical and natural gas industries - Production
assurance and reliability management.
ref./ 25 VDI 4640 (parts 1 to 4) in Germany
ref./ 26 VDI 4650 (parts 1 & 2) in Germany
ref./ 27 NORMBRUNN – 07 in Sweden
ref./ 28 “Geothermal heat pump borehole heat exchanger fields : guideline for design and
implementation” (BRGM and ADEME, 2012) in France
ref./ 29 Geothermal energy and heat networks. Guideline for operators (BRGM and
ADEME, 2010) - France
ref./ 30 BRL SIKB 2100: Mechanical drilling - The Netherlands
ref./ 31 BRL SIKB 11000: Design, realisation, management and maintenance of the
subsurface part of SGE systems - The Netherlands
ref./ 32 ISSO-publications 39, 72, 73, 80 en 81: For the technical implementations of the
above ground part of an SGE system - The Netherlands
ref./ 33 NEN 7120: for calculating the EPC of a building - The Netherlands
ref./ 34 API RP14E for calculating erosional velocity limits
ref./ 35 DNV RP G-101 Risk Based Inspection of Offshore Topside Static Mechanical
Equipment
ref./ 36 Data sheet GEO-process ECW , Data sheet GEO-process ECW. 27/10/2016
ref./ 37 QHSEP Risc Matrix (rev02).xlss ; provided by Dio Verbiest, DAGO Operation
Secretary, email 14/02/2018
ref./ 38 Offshore Installations and Wells (Design and Construction, etc.) Regulations 1996,
DCR – regulations 13, 15 and 16
ref./ 39 Report presenting proposals for improving the regulatory framework
for geothermal electricity - Appendix 1; Deliverable 4.1, S Fraser; 2013;
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http://www.geoelec.eu/wp-content/uploads/2011/09/D4.1-A.1-Overview-of-National-Rulesof-Licencing.pdf
ref./ 40 Recommended Minimum Functional Specification and Standards for geothermal
Wells in the Netherlands V.5, Well Engineering Partners BV, http://wellengineering.nl/wpcontent/uploads/2012/01/Minimum-Functional-Specifications-and-Standards-forGeothermal-wells-v5-beveiligd.pdf, viewed January 2018.
ref./ 41 Abandonment Coast Estimation Geothermal Installation, DAGO, May 2016,
D7276R00.5608
-o0o-
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Methodology to develop the Asset
Management Guideline
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A.1
General
The guideline has been developed on the basis of Oil & Gas standards; good practices,
general asset management standards and a web based literature review, but adapted to
suit the Dutch geothermal industry.
The guideline is aiming to provide guidance on procedures, plan, program, database,
management systems needed to ensure an optimum Asset Management. However, the
guideline is developed to keep the documentation requirements and activities to be
performed to the size of typical Dutch Geothermal Industry asset. The ALARP principle has
been followed to ensure risks are managed to a level that is as low as reasonably
practicable, including HSE risk and Security.
This guideline provides guidance on procedures, plan, program, database, and
management systems needed to ensure optimum Asset Management. The aim has been to
formulate the general requirement and principles of the ISO 55000 series, including other
standards and codes, into a more specific AM guideline.
A.2
Guideline contents rationale
Information relating to regulation are extracted from ref./ 4 . The lack of good practices in
the different European regions/countries has been identified as barriers in the geothermal
asset assessments. As stated in ref./ 18, “the lack of actual industry experience has been
often compounded by lack of understanding of non-geological technical/organisational
risks, absence of minimum or good practice standards, lack of knowledge transfer from
other subsurface knowledge areas (oil and gas industry), in terms of maximizing knowledge
flow and setting minimum standards”. The strand B report focused on making a guideline
so that Dutch Geothermal Industry can create AMP’s for their assets.
Guidance on the economical investment decisions for geothermal wells / plant is not part of
the scope. The geothermal investment guide ref./ 16 indicates that plant availability,
lifetime of the plant, competence and experience of risk mitigation are key requirements to
be addressed in the Plan. (ref./ 16). The GEOLEC Investment Guide on Geothermal
Electricity also provides background about existing technologies and analyses the factors
for the success of geothermal project, the different level of risks involved in the various
phases and the options to finance each of these phases. Though all these recommendation
do not apply to LEGE asset (no electricity, smaller Business) some points were relevant. As
a result, the guideline is including Reliability Maintainability and availability Analysis (RAM)
section. However, RAM is not mandatory when business is small and the operator and the
end user is the same owner.
Existing standards and recommended practices have been used to structure this guideline
(see Section 2.1). These standards / RP’s are typically from the Oil & Gas industries in
Norway and Netherlands. The key references are ref./ 3 , ref./ 5 , ref./ 2 , ref./ 6 , ref./
7 , and ref./ 8 . The general ISO 55000 series have been used to structure and address
the fundamentals content of an Asset Management plan & systems.
The application of the ISO 55000 series requirements has been simplified and adapted to
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Dutch Geothermal Industry business size and LEGE asset Characteristics. The asset
management system requirements described in ISO 55001 are grouped in a way that is
consistent with the fundamentals of asset management:

context of the organisation

leadership

planning

support

operation

performance evaluation

improvement
The Dutch geothermal industry does not adopt a particular ISO, API or NORSOK standard
but rather uses specific elements of these where applicable, such as defining a basis of
Design, performing a hydrocarbon risk assessment and the development of a Risk Register
(as per ISO16530) that carries through the entire well lifecycle (ref./ 9 ).
Asset Management is performed using a risked based approach. During the HAZID
preparation (ref./ 1) risk matrices were proposed based on Hazid Project stakeholders and
various operators across the Dutch Geothermal Industry. The risk matrices developed are
consistent with the guidance provided by EN ISO 17776:2002 (ref./ 23) and comprise a
summary 6x5 consequence versus probability matrix supported by five further matrices in
which consequences are rated more explicitly in terms of People, Environment, Assets,
Reputation and Social impacts. The same matrices are therefore proposed to perform any
risk assessment at different phase of the geothermal asset life and for RBI and RBM. This
is presented in ref./ 37.
Geothermal Asset Operator shall demonstrate their compliance with regulatory bodies
including HSE and demonstrate good Asset Management practice to their various
stakeholder and shareholders. QHSE section referred to QSHE program currently on going
(see Section 3.5.5).
No Information on Dutch regulation has been received at the date of issue of this report
revision from the project. However information has been taken from an EU project (ref./ 4
). Regulation, standards, and relevant EU directives are therefore discussed as they should
apply to Dutch operations.
A specific section on systems / equipment / components is included within Section 3.6 of
this guideline. The aim is to provide practical information regarding degradation threats, and
a general check list for the risk assessment methodology, i.e. risk based scenarios to
support the development of RBI and RBM programs. Based on Wood Group experience
and expertise; typical threats, inspection, testing, monitoring and maintenance requirements
are described. Similarly, specific operational philosophies and asset integrity information
are presented and further developed in the appendices. Finally, AM plan development and
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contents through the asset life cycle is also described based both on Wood Group
experiences, international standards and additional literature listed in Reference section
3.7.7.
A.3
Literature review
A brief literature review was performed related to asset management activities, including
risk document, maintenance, and deep geothermal activity in Iceland and New Zealand.
Note that literature review related to Netherland and Europe are limited.
NZS 2403:2015 - Code of practice for deep geothermal well has been reviewed for well
maintenance (ref./ 2 ) This New Zealand good practice covers the techniques and
procedures to be adopted throughout the life of a well. This includes monitoring, inspecting,
and repairing the well and wellhead components, and the production/injection well.
However, it focuses on high enthalpy geothermal assets and as such not all information are
relevant to LEGE. Wood Group Intetech report (ref./ 9 ) has been manly used to develop
Well and piping equipment IMT&M in section 3.6.
When it comes to Risk Management, Loizzo (ref./ 22) proposed to use “evidence-based
scenario” to screen out threats from check list when evidence can be shown that the threat
is not really relevant to the asset the purpose is to avoid detailed analysis. It screens out
Risk/threats from detailed analysis threats which are rare and focus on relevant possible
threats, while still identifying them. Typical example will be seismic threats.
Litchi (ref./ 20 ) recommends the use of RBI for Geothermal plant, and also refers to
pressure vessel standards for inspection AS/NZS 3788:2006 standard.
Chinedu (ref./ 19) has proposed Asset Integrity Management Framework for Renewable
Energy generation, including geothermal Asset. The procedure for sustainable asset
integrity management broadly comprises of three operations, namely, mitigation, control
and regulatory programmes in his framework as shown in Figure 9.
Figure 9 Hierarchy of elements of sustainable asset integrity management programme.
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(ref./ 19)
The article is providing interaction with stakeholders for feedback mechanism, plant
performance and Interaction of asset integrity indicators and plant management team. This
article AM framework aligns with the overall framework developed in this document. The
article concludes that implementation of the outlined strategies have “the potential to
improve the integrity of assets used in renewable energy plants due to the integrated
organisational function interfaced mitigation approach that makes fault dictation timely.
Mitigation strategies provide a holistic asset integrity performance measurement through a
systematic feedback mechanism and by weighted balancing of social, economic and
environmental KPIs”.
Chinedu further stated that “adoption of sustainable AM improvement performance
principles of control, competence, communication, coordination and compliance will not
only reduce downtime, ageing deterioration, accidents, pollution and incidents but will also
aid in improved lifecycle performance of the assets via a feedback modulated framework.
This conclusion has been used to develop the AM guideline.
Other references used to build up the guideline are listed in Reference section 3.7.7.
A list of remedial and mitigation/ activities to geothermal asset threats have been used (ref./
10 , ref./ 9 and ref./ 11 to be applied both at the design and operational phases.
Guidelines for improving well injectivity presented in ref./ 10 have been reviewed.
A.1
Asset Integrity Management Definitions
Definition related to asset management might differ slightly from standard to standard.
Therefore, for the sake of clarity, definitions are recapped hereafter; the following definitions
are extracted from standard reference in section 3.7.7. ISO 55000 1, 2 & 3 series has
mainly been used whenever relevant and available.
Asset Integrity: Ability of an asset to perform its required function effectively and efficiently
whilst protecting HSE.
Asset life: Period from asset creation to asset end-of-life.
Asset management plan: Documented information that specifies the activities, resources
and timescales required for an individual asset or a grouping of assets, to achieve the
organisation’s asset management objectives
Asset Management System: Management system for asset management which function is
to establish the Asset Management policies and objectives.
Asset Management: Coordinated activity of an organisation to realise value from assets.
Asset: Item or entity that has potential or actual value to an Organisation.
Audit: Systematic, independent and documented process for obtaining audit evidence and
evaluating it objectively to determine the extent to which the audit criteria are fulfilled.
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Incident: Unplanned event or occurrence resulting in damage or other loss.
Inspection: Appraisal involving examination, measurement, testing, gauging, and
comparison of materials or items.
Integrity: State of a system performing its intended functions without being degraded or
impaired by changes or disruptions in its internal or external environments.
Life cycle: Stages involved in the management of an asset.
Maintenance: A combination of all technical, administrative and managerial actions during
the life cycle of an item intended to retain it in, or restore it to, a state in which it can perform
the required function.
Monitoring: Determining the status of a system, a process or an activity.
Performance indicator: Monitoring and measurement of the effectiveness of Asset Integrity
Management as per SMART principle. Performance indicators can be Leading or Lagging.
Policy: Intentions and direction of an organization as formally expressed by its top
management.
Process: Set of interrelated or interacting activities which transform inputs into outputs.
RBI: Process of developing an inspection plan based on knowledge of the risk of failure of
the equipment.
RBM: Prioritizing maintenance resources towards assets carrying the most risk in case of
failure.
Reliability: Ability of a system to consistently perform its intended or required function or
mission, on demand and without degradation or failure.
SMART objectives: Goals that are characterised by being Specific, Measurable,
Assignable, Realistic and Time-related.
Supply Chain Management: Ensures that reliability, integrity, obsolescence risks and
technical risk management goals, requirements, achievements and lessons learned are
communicated between all organisations.
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Risk Assessment Methodology & Risk
Matrices
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Risk Assessment - General
A Risk Based Assessment is used to identify component degradation mechanisms,
inspection and maintenance programs. This provides assurance on the operational
integrity of the assets, with rating and review of all systems being the responsibility of the
Asset Integrity Team. Risk Assessment (RA), either qualitative and/or quantitative, are
performed to define threats to the asset and its components with regards to Integrity, HSE,
and business perspective. The objectives of the RA are:

Identify potential risk of failure or degradation for system and components.

Identify the main hazards and operability consequences.

Use relevant standard, models for assessing, which are crosschecked against real
data / experience in other operating units.

Recommend measures suitable to mitigate the threat.
Note that:
1. The RA form the basis of the Project Risk Management prior Production,
2. The RA form the basis of the Risk Based Inspection (RBI) and Risk Based
Maintenance (RBM) scheme during Production.
The risk Matrices are extracted from QHSE Framework ref./ 37.
Risk Methodology
The risk assessment study should involve the input from a multi-disciplined team, with team
members representing, at a minimum, the following groups or disciplines: Reliability
engineer, Integrity engineer, production engineer, maintenance engineer, well / reservoir
engineer.
All Life Cycle phase shall be risk assessed. It is recommended to use an “evidence-based
scenario” to screen out threats from check list when evidence can be shown that the threat
is not really relevant to the asset the purpose is to avoid detailed analysis. It screens out
Risk/threats from detailed analysis threats which are rare and focus on relevant possible
threats, while still identifying them.
Typical example will be seismic threats. This approach is recommended from Concept to
Operation phases. The purpose of the “evidence-based scenario” method is to ensure that
appropriate effort is made on each threat based on the expert judgment and inspection,
monitoring, testing and maintenance information available.
1) At Concept and Design phase, RA shall focus on identifying Risk & Opportunity related
to selection of specific equipment and specific functions required to deliver Asset
Performance. CAPEX cost and OPEX life cycle Cost and HSE Requirement to comply
with Regulation and policies shall be considered.
2) During the Operational phase, RA is performed either through RBI and RBM activities
with the objectives to use a risk based approach to address inspection and
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maintenance priorities account for risk and resource available.
Risk Assessment frequency
Good and time efficient practice is to prepare these RA and review them with relevance in a
workshop. The focus will be on key identified risks, while keeping other risks reviewed by
the risk assessment team.
Risk Assessment frequency should be performed as follows:
1) Prior to Operations, RA should be perform on a regular basis, Prior to any subcontracts
being awarded, prior to key milestones for the project
2) During Operation, RA shall be performed for unplanned anomaly and a yearly workshop
should be planned with all stakeholders as a minimum.
Quarterly / continuous review of anomalies found might be required for Critical Risk
identified for Asset Operation.
Probability of Failure (PoF) & Consequence of Failure (CoF)
Probability of failure is estimated based upon the types of damage expected to occur in a
component and is assessed utilising the design information, operating history, inspection
findings and engineering judgements based on industry experience and any other relevant
literature.
The CoF is dependent on the failure mode and physical location, where the latter is affected
by factors such as Quality, Health, Safety Technical, Environmental and Public Acceptance.
Table 4-1 Risk = CoF x PoF (Quality)
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Table 4-2 Risk = CoF x PoF (Health)
Table 4-3 Risk = CoF x PoF (Safety)
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Table 4-4 Risk = CoF x PoF (Environment)
Table 4-5 Risk = CoF x PoF (Public Acceptance)
Risk Matrix
Risk is defined as: 𝑅𝑖𝑠𝑘=𝑃𝑜𝐹 ×𝐶𝑜𝑓
For both the internal and external threats, the risk will be calculated based on the above
definition, where PoF and CoF shall be combined to give a risk rating.
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Table 4-6 Risk Matrix
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Detailed Information on Standards
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The good practice guidelines identified to the support and development of the LEGE sector
into the mature regions like the Netherlands are included hereafter:

Netherlands
o
BRL SIKB 2100: Mechanical drilling - The Netherlands ;
o
BRL SIKB 11000: Design, realisation, management and maintenance of the
subsurface part of LEGE systems - The Netherlands ;
o
ISSO-publications 39, 72, 73, 80 en 81: For the technical implementations of
the above ground part of an LEGE system - The Netherlands ;
o
NEN 7120: for calculating the EPC of a building - The Netherlands

API RP14E for calculating erosional velocity limits

VDI 4640 (parts 1 to 4) in Germany ; VDI 4650 (parts 1 & 2) in Germany

NORMBRUNN – 07 in Sweden

“Geothermal heat pump borehole heat exchanger fields: guideline for design and
implementation” (BRGM and ADEME, 2012) in France; Geothermal energy and
heat networks. Guideline for operators (BRGM and ADEME, 2010) - France
This list is non exhaustive.
Hereafter, general requirements from ISO 55000 series are described:
o
data management;
o
non-destructive testing;
o
condition monitoring;
o
pressure equipment;
o
risk management;
o
financial management;
o
quality management;
o
value management;
o
environmental management;
o
shock and vibration;
o
systems and software
engineering;
o
acoustics;
o
qualification and assessment
of personnel;
o
life cycle costing;
o
dependability (availability,
reliability, maintainability,
maintenance support);
o
project management;
o
property and property
management;
o
configuration management;
o
facilities management;
o
technology;
o
equipment management;
o
sustainable development;
o
commissioning process;
o
inspection;
o
energy management
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Inspection, Testing, Monitoring Techniques
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This appendix describes some of the inspection, Monitoring and testing method available.
The list is non-exhaustive; the list focuses on key methods. List of element to be analysed
in Water & Gas analysis is listed at the end of this section.
Coupons (ref./ 11 and ref./ 9)
Coupons can predict the following types of corrosion when correctly placed to ensure
appropriate exposure: general corrosion, crevice corrosion, pitting, stress corrosion
cracking, embrittlement, galvanic corrosion, and metallurgical structure-related corrosion.
Monitoring with coupons is relatively simple and cheap. Coupons are small pieces of metal,
usually of a rectangular or circular shape, which are inserted in the process stream and
removed after a period of time for assessment. The most common and basic use of
coupons is to determine average corrosion rate over the period of exposure. The average
corrosion rate can easily be calculated from the weight loss, the initial surface area of the
coupon and the time exposed.
However, coupons have several limitations. An extended period of time is required to
produce useful data, and coupons can only be used to determine average corrosion rates.
Corrosion coupons can also be used to investigate the lead deposition rate and/or scaling.
It is advisable to leave a coupon exposed for at least 30 days to obtain valid corrosion rate
information, and a longer period (e.g. 6 months) is typical. There are two reasons for this
recommended practice. First, a clean coupon generally corrodes much faster than one
which has reached equilibrium with its environment. This will cause a higher corrosion rate
to be reported on the coupon than is actually being experienced on the pipe or vessel.
Second, there is an unavoidable potential for error as a result of the cleaning operation.
Another benefit of coupons is to provide information about the type of corrosion. Unlike
electrochemical probes, which only detect the corrosion rate, coupons can be examined for
evidence of scaling, pitting and other localized forms of attack.
Corrosion Probes (ref./ 9)
The major advantage of probes compared to coupons is that measurements can be
obtained on a far more frequent basis - essentially continuous. Also, readings do not
require removal of the probe.
Electrical resistance (ER) systems work by measuring the electrical resistance of a thin
metal probe. As corrosion causes metal to be removed from the probe, its resistance
increases.
Electrochemical probes consist of several individual electrodes and allow one or more
electrochemical methods to be used to measure corrosion rate. Typical methods include
Linear Polarisation Resistance (LPR), Electrochemical Noise and Electrochemical
Impedance. In favourable conditions, electrochemical probes can provide detailed and rapid
information. Electrochemical (LPR) probes are a standard technology for water systems
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generally, and are suitable for geothermal applications.
According to DAGO (2016), several operators use continuous inline measurements in the
brine flow, either in the main flow, or through a bypass with a comparable flow rate.
Measurements techniques include both LPR and ER.
Corrosion loops/bypass (ref./ 11 and ref./ 9)
A corrosion loop is a section of tubing that some of the flow is passed through a pipe
running parallel to the main piping. As the Material and piping size is similar it can more
easily be monitored on corrosion, scale or lead deposits.
Corrosion probes can be installed in the loop to provide facilities for on-line investigation of
the use of new inhibitors or process parameters.
Several Dutch operators have installed corrosion loops in collaboration with chemical
suppliers for the purposes of on-line monitoring of inhibitor performance.
In-situ inspection tools (ref./ 11 )
There is an extensive list of in-situ inspection tools called logs.

Calliper logs, also known as multi-finger callipers, measure the internal radius of the
casing in several directions by using multi-finger feeler arms of the tool. The multifinger calliper survey can measure anomalies only on the inner surfaces of the
tubing or casing. Output reports can provide the average wall thickness loss and
also some indication of the maximum local wall thickness loss. The Multi-Finger
Calliper may also be used to measure the build-up of scale, paraffin or other mineral
deposits in the wellbore.

Electromagnetic thickness logs are one of two available electromagnetic measuring
methods for corrosion monitoring. These logs are carried out by electromagnetic
induction tools. Electromagnetic (eddy current) logs can give information on the total
wall thickness of up to three strings, with some indication as to whether loss of
thickness is on the inner or outer strings.

Magnetic flux logs make use of magnetic flux leakage (MFL) technology to
determine the location, extent and severity of corrosion and other metal loss defects
in the inner tubular string.

Near locations of defects such as corrosion or pitting, some of the flux leaks out of
the pipe, and these leaks are detected by the tools sensor arrays.

Ultrasonic corrosion logs employ a very high transducer frequency to measure
anomalies in the tubing or casing. The emitter sends out sound waves and the
detector measures the reflected response. It is able to provide information about
casing thickness, surface condition and small defects on both internal and external
casing surfaces.

Using a gamma-ray (GR) measurement log, it is possible to detect scaling of
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radioactive material.
Corrosion Detection in well

Note that corrosion can be assessed by monitoring the production rate, pressure,
temperature, and fluid corrosivity at the well-head, and their change in time. During
shut down and maintenance of the well equipment, downhole camera and casing
integrity inspection logs can be applied to verify the degree of corrosion. However,
these latter methods are relatively expensive. On technical and financial grounds, it
is unnecessary and undesirable that they are executed on a high frequency basis.

Electrochemical noise measurements (ENM), electrochemical
spectroscopy (EIS) and linear polarization resistance (LPR)
impedance
Electromagnetic technology (EM) (ref./ 12 )
The technique used is called Pulsed Eddy Current (PEC) where a short high-energy EM
pulse from a transmitter coil “charges” the surrounding concentric pipes. Immediately after
the excitation pulse, a co-located receiver coil measures the collapsing eddy currents.
Embedded within this received “decay” curve is a complex signature, which is a function of
the surrounding pipe’s geometry and EM properties. The advantage of this technique is that
the source of the problems can be located without the need to “pull the completion” as the
slim PEC tool can be run through tubing. Another application is the evaluation of surface
casing behind the cemented production string.
Cement Evaluation Using Radial Bond Log (RBL) (ref./ 12 )
“The Radial Bond Log (RBL) simultaneously evaluates the quality of cement bonding as
well as the condition and integrity of both the pipe and formation by calculating the
measurements of the cement bond amplitude through near receivers, variable density log,
and far receivers.”
“The primary use of this technology is to guarantee the integrity of the well by ensuring that
the cement is effectively placed between the casing strings and the formation. Poor cement
placement can typically result in unwanted situations such as water or gas production and
fluid migration. With RBL, it is possible to get an accurate insight into the quality of the
cement, which is extremely important, as a correct diagnosis and assessment of the
problem is essential to understanding the remedial work required for gas and water wells.”
Combining Technologies
“In many cases when an operator would like to evaluate the integrity of the well to check if it
is fit for production or injection, multiple sensors are required in order to give a complete
assessment. However, the financial aspect is an important factor when doing so”.
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Water & Gas Analysis Monitoring
Element to be analysed
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