Guidelines & Recommended Practices
Selection of Artificial Lift Systems
for Deliquifying Gas Wells
4.2 Know and practice pertinent guidelines and recommended practices for
automation, surveillance, and optimization of each form of artificial lift
This section provides information, guidelines, and recommended practices
for automation, surveillance, and optimization of artificial lift systems for gas
well deliquification.
Rather than repeat information here that is covered in other documents, the
primary purpose here is to provide references to locations where automation
information can be found. Two specific references and some specific comments are given.
4.2.1 Outline of Chapter 15 of Gas Well Deliquification, Production Automation
There is a comprehensive discussion of production automation for gas well
deliquification in Chapter 15 of “Gas Well Deliquification, Second Edition,” by James F. Lea, Henry V. Nickens, and Mike R. Wells. This book is
available from “Gulf Drilling Guides” published by Elsevier Press. Chapter
15, entitled “Production Automation” is written by Cleon Dunham and
Greg Stephenson. An outline of the chapter is presented below so the
reader can see the breadth and depth of coverage of automaton for gas
well deliquification.
15.1
Introduction
Surveillance
Control
Optimization
15.1.1
Gas Well Deliquification
15.1.2
Gas Well Dewatering
15.2 Brief History
15.2.1
Well-Site Intelligence
15.2.2
Communications
15.2.3
System Architecture
15.3 Automation Equipment
15.3.1
Instrumentation
Pressure Transmitter
Differential Pressure Transmitter
Temperature Transmitter
Multivariable Transmitter for P, DP, and T
Selection of Artificial Lift Systems for Deliquifying Gas Wells
15.3.2
15.3.3
15.3.4
15.3.5
15.3.6
15.3.7
Page 2
Table 15-1 --- Types of Signal Outputs
Types of Signal Outputs from Transmitters
Electronic Flow Measurement
System Description
Algorithms
Sampling Frequency
Data Availability
Audit and reporting Requirements
Equipment Installation
Equipment Calibration/Verification
Security
Controls
Automatically Controlled Valves and Accessories
Fluid Controlled Valves
Electrically Controlled Valves
Production Safety Controls
Motor Controllers
Switchboards
Variable Frequency Drives
RTUs and PLCs
RTUs
PLCs
Host Systems
General Automation Systems
Equipment Specific Systems
Home Grown Systems
Generic Oil and Gas Systems
Communications
Instrument to RTU
RTU to Host
Table 15-2 --- Methods of Communication between
RTUs and Host
Table 15-3 --- Communication Standards
Host to Users
Table 15-4 --- Communication Protocols
Table 15-5 --- Methods of Data Security
Host to Computer Systems
Computer Systems to Users
Database
Overview
Database Models and Schema
Storage
Indexing
Real-Time Databases
FIFO
Historians
Selection of Artificial Lift Systems for Deliquifying Gas Wells
15.3.8
Other
15.4 General Applications
15.4.1
User Interface
15.4.2
Scanning
15.4.3
Alarming
Class I Alarms
Class II Alarms
Class III Alarms
15.4.4
Reporting
Current Reports
Daily Reports
Historical Reports
Special Reports
Unique Application Reports
15.4.5
Trending and Plotting
Trend Plot of Two Variables
15.4.6
Displays
Unique
Generic
Static
Dynamic
Interactive
15.4.7
Data Historians
15.5 Unique Applications for Gas Well Deliquification
15.5.1
Plunger Lift
Measurements
Control
Unique Hardware
Unique Software
On Pressure Limit Control
Off Pressure Limit Control
Specialized Alarms
Surveillance
Analysis
Design
Optimization
15.5.2
Sucker Rod Pumping
Measurements
Control
Unique Hardware
Unique Software
Specialized Alarms
Surveillance
Analysis
Page 3
Selection of Artificial Lift Systems for Deliquifying Gas Wells
15.5.3
15.5.4
15.5.5
15.5.6
15.5.7
15.5.8
15.5.9
15.5.10
Design
Optimization
PCP Pumping
Measurements
Control
Unique Hardware
Unique Software
Specialized Alarms
Analysis
Design and Optimization
ESP Pumping
Measurements
Control
Start, Stop, and Safety Shutdown
Control of Wells with FSD’s
Control of Wells with VSD’s
Control of Wells on Start-Up
Unique Hardware
Unique Software
Specialized Alarms
Surveillance
Analysis
Design and Optimization
Hydraulic Pumping
Surveillance
Control
Chemical Injection
Surveillance
Control
Gas-Lift
Measurements
Control
Unique Hardware
Unique Software
Specialized Alarms
Surveillance
Analysis
Design
Optimization
Wellhead Compression
Surveillance
Control
Heaters
Surveillance
Control
Cycling
Page 4
Selection of Artificial Lift Systems for Deliquifying Gas Wells
15.5.11
15.5.12
Surveillance
Control
Production Allocation
Other Unique Applications
15.6 Automation Issues
15.6.1
Typical Benefits
Tangible Benefits
Intangible Benefits
15.6.2
Potential Problem Areas
Automation System Design
Instrumentation Selection
Automation Hardware and Software Selection
Environmental Protection
Communications
Project Team
Integration into the Organization
15.6.3
Justification
The Impact of Time
Acceleration vs. Increased Recovery
The Role of Pilot Tests
15.6.4
CAPEX
15.6.5
OPEX
15.6.6
Design
People
Process
Technology
15.6.7
Installation
15.6.8
Security
Field Devices
Host Systems
15.6.9
Staffing
Table 15-6 --- Production Automation Teams
Steering Committee
Automation Team
Surveillance Team
15.6.10
Training
Aware
Table 15-7 --- Automation Trading Requirements
Knowledgeable
Skilled
15.6.11
Commercial vs. In-House
15.7 Case Histories
15.7.1
Success Stories
Rod Pump Controllers
Page 5
Selection of Artificial Lift Systems for Deliquifying Gas Wells
15.7.2
Page 6
Plunger Lift Automaton
Host System/Workflow Management
Failures
Beam Pump Optimization
15.8
Summary
15.9
References
4.2.2 Outline of API Recommended Practice 19G12 --- Gas-Lift Automation
Second, an API Recommended Practice (API RP 19G12) is being prepared to cover automation of gas-lift operations. This recommended practice focuses on automation of gas-lift wells and systems but many of the
principles also apply for automaton of other gas well deliquification processes. As of March 2011, this document is still being drafted. A copy of
the draft version can be obtained for use until the final version is printed by
the American Petroleum Institute. At that time it can be purchased from the
API. An outline of this document is provided below.
1
Scope
2
Normative References
3
Terms and Definitions
4
Symbols and Abbreviations
5
Requirements
5.1 Introduction to Gas-Lift Automation
5.1.1 Production Automation Defined
5.1.2 Overview of Gas-Lift Automation
5.1.3 Objectives of Gas-Lift Automation
5.1.4 Use of Data Collection and Processing Technology for Gas-Lift
Automation
5.15 Types of Field That Need to be Served by Gas-Lift Automation
5.2 The Business Side of Gas-Lift Automation
5.2.1 Gas-Lift Automation Business Drivers
5.2.2 Justification for Gas-Lift Automation
5.2.3 Gas-Lift Automation Risks
5.2.4 Gas-Lift Optimization
5.3 Gas-Lift Automation Hardware and Software
Selection of Artificial Lift Systems for Deliquifying Gas Wells
5.3.1
5.3.2
5.3.3
5.3.4
Page 7
Gas-Lift Automation Hardware Issues
Gas-lift Automation Software Issues
Gas-Lift Automation Applications
Gas-Lift Database Applications
5.4 Gas-Lift Automation Issues
5.4.1 Gas-Lift Automation People/Staffing Issues
5.4.2 Training Required for Gas-Lift Automation
5.4.3 Training Methods for Gas-Lift Automation
5.5 Gas-Lift Automation Case Histories
5.5.1 Case Histories – Successful Gas-Lift Automation Systems
5.5.2 Case Histories – Unsuccessful Gas-Lift Automation Systems
6
Annexes
7
Bibliography
4.2.3 Specific Comments on Automation of Artificial Lift Systems for Gas
Well Deliquification
Some specific comments on automation for gas well deliquification are provided in this section. These comments pertain to specific examples of actual automation systems for artificial lift applications, and benefits that have
been realized by application of automation.
4.2.3.1
4.2.3.1.1
Sucker rod pumping
Automation examples
Thousands of sucker rod pumping wells have been automated,
both for oil and gas wells. A rod pump control (RPC) unit is installed at the well. It measures polished rod load and position.
It determines if the well is pumped off or not, and it checks on
loads to see if the pumping unit is overloaded or under loaded.
The RPC communicates with a “host” automation system to
send information on pumping time and parameters. From this
information, the host system can determine both surface and
downhole system and pump performance.
4.2.3.1.2
Benefits
Typical benefits of sucker rod pump automation have been determined by many studies. They include:
 5 – 10% production increase.
Selection of Artificial Lift Systems for Deliquifying Gas Wells


15 – 20% energy savings.
30 – 35% reduction in repair and maintenance costs.
4.2.3.2
Progressing cavity pumping
4.2.3.3
Electrical submersible pumping
4.2.3.4
Hydraulic pumping
4.2.3.5
Plungers
4.2.3.6
Soak sticks
4.2.3.7
Batch chemical treatment
4.2.3.8
Continuous chemical injection
4.2.3.9
Velocity strings
4.2.3.10 Surface compression
4.2.3.11 Continuous gas-lift
4.2.3.12 Intermittent gas-lift
4.2.3.13 Injection
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