PRODUCTION WELL CASING INTEGRITY
VERIFICATION TO PREVENT LEAKS
Dexon’s Production Well Casing In-line
Inspection (ILI) program utilizes
ultrasonic technology to offer
comprehensive anomaly detection and
sizing capabilities. Advanced sensors
provide direct wall thickness data for
precision measurement of corrosion and
other metal loss anomalies to 1.3 mm
remaining wall thickness. Bi-directional
tool operation guarantees high-density
sampling rates for each casing, ensuring
100% probability of detection of critical
defects and extremely thin piping.
On-site field reporting of thin and
corroded piping provides actionable
information, reducing the risk of
downtime. Detailed final reporting
provides data for continued operations
and scheduled maintenance, to ensure
efficient, profitable, and safe operation.
Dexon’s ultrasonic multi-channel
transducer configurations offer quick
inspection speed, reducing downtime
and resulting in increased productivity.
THREATS TO PRODUCTION
WELL CASING STRINGS
Leaking Produced Water
Water used in hydraulic fracturing (produced water)
contains potentially dangerous chemicals such as naturally
occurring hydrocarbons, radioactive materials, metal ions,
and additives that pose threats to the environment. Leaks
in the intermediate casing zone allow these chemicals to
enter and contaminate groundwater.
Leaks may occur when groundwater seeps through the
cement lining and settles on production casing strings,
resulting in critical defects forming between the
production casing and the cement lining, with the
potential to contaminate groundwater. Dexon’s Production
Well In-Line Inspection program offers comprehensive
inspection and detection of defects and anomalies in
casing strings that can lead to leaks.
Corrosion and Pitting
Production wells are generally susceptible to the following
anomalies occurring within the pipe wall:
General Corrosion
Uneven metal loss over a large area
of the pipe wall.
Pitting
Localized corrosion producing holes
(pits) in the pipe wall. Detection of
pitting can be difficult with other
technologies in providing correct
and concise sizing of individual
anomalies (pits).
COMPREHENSIVE THREE-TIER REPORTING
Dexon’s Production Well Casing In-Line Inspection program guarantees asset integrity with
a three-tiered reporting system adhering to POF recommendations:
On-Site Field Reporting
Summary of important operational information
o Immediate interpretation of inspection data
o Identification of critical defects for immediate review
o Immediate clarification of well conditions, allowing for the safe continuation of product delivery or rapid
intervention by client if critical anomalies are identified
o Automated software detection of high consequence areas
o
Preliminary Reporting
o Reporting
o Reporting
of all anomalies with an Estimated Repair Factor (ERF) greater than or equal to 1
of all defects with a depth greater than or equal to 50% of nominal wall thickness
Final Reporting
o Top
Level assessment of well casing integrity including immediate threats to continued safe
operation
o Full listing of all anomalies detected with a wall loss greater than or equal to 1 mm with pressure
sentenced Estimated Repair Factor (ERF)
o Detailed Anomaly Sheets on all anomalies identified exhibiting dimensions exceeding
pre-determined severity criteria
Groundwater Zone
The groundwater zone includes
all geologic formations of soil,
sand and rock containing
groundwater that are
susceptible to groundwater
contamination.
Production Zone
The production zone is the
section of casing that is
intentionally perforated to
allow gases and liquids to flow
through the intermediate
casing to the surface for
extraction. For this reason, the
production zone does not
require inspection.
Inspection Zone
The zone under inspection
includes the entire casing string
from the ‘Christmas Tree’ on the
surface to the production zone.
HIGH-RESOLUTION PRODUCTION
WELL IN-LINE INSPECTION FLEET
Dexon’s ultrasonic multi-channel well inspection fleet features eight rows of off-set
ultrasonic transducers oriented around the circumference of the tool. Probability of
anomaly detection is based on sampling density, with higher resolution inspection data
resulting in a higher probability of detection. Dexon’s production well inspection tools
achieve a minimum of 190,476 samples per m2 of pipe wall at 0.34 m/s, providing highly
accurate inspection data. Capable of inspecting 500m of pipe every 24.5 minutes, allowing
for the inspection of up to five wells per day per team. These higher inspection speeds
lead to less well downtime, resulting in reduced inspection costs and increased well
productivity.
Key Inspection Figures
• 1.5mm Axial Ultrasonic Sampling Resolution @ 0.34m/s
• 1.5mm Circumferential Ultrasonic Sampling Resolution
• 190,476 Raw Direct Measurement Data Samples Per m2
• Bi-directional Inspection
• 24.5 Minute Inspection Time Per 500m
• 160 Ultrasonic Transducers
• Tool Speed: 60m/min
DEFECT DETECTION VERIFICATION
Ultrasonic inspection data provides direct measurement of defects including defect size,
location, remaining wall thickness, and metal loss percentage. This data is used to
accurately determine pipeline condition and to provide a calculated Estimated Repair
Factor (ERF) of each individual defect, ensuring asset integrity. The data set below shows
artificial defect detection verification samples, taken from Dexon’s test yard facilities.
DEFECT SIZE
MULTI-CHANNEL UT-MC (0.34M/S)
3 mm
80%
4 mm
95%
5 mm
99%
HIGH-RESOLUTION
PRODUCTION WELL
IN-LINE INSPECTION
1.5mm
Axial Ultrasonic Sampling
Resolution @ 0.34m/s
1.5 mm
Circumferential
Sampling Resolution
3.24mm
3.24mm
Ultrasonic Beam
Diameter
Ultrasonic Inspection
Data Sample
190,476
190,476 Raw
Data Samples
2
Per m
Bidirectional
Inspection
PHONE: +66 33 012484-7
INFO@DEXON-TECHNOLOGY.COM
WWW.DEXON-TECHNOLOGY.COM