IPTC 17465 A Comprehensive Approach of Well Integrity Surveillance
IPTC 17465 A Comprehensive Approach of Well Integrity Surveillance
IPTC 17465 A Comprehensive Approach of Well Integrity Surveillance
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Abstract
The well integrity surveillance program is a mechanism applied to oil, gas and water production/injection wells to
ensure the sound quality and healthiness of all their completion components. Currently, there are differences in
the well integrity surveillance programs applied by field operators worldwide due to the differences in the causes
of well integrity issues that are faced in every field or geographical location. Recognizing such differences, Saudi
Aramco formed a Well Integrity Surveillance Guidelines and Best Practices (WISG&BP) team to review and
establish a comprehensive well integrity surveillance program that can be applied corporate wide for all well types
(oil, water and gas).
The developed program not only ensures the identification of well problems at its infancy but also maintains the
healthiness and upkeep of Saudi Aramco asset. This surveillance program focuses on the following six primary
well integrity surveys: 1) Wellhead valves integrity inspection and greasing. 2) Surface and Subsurface Safety
Valves (SSV & SSSV) and Emergency Shut-Down (ESD) System functionality and integrity testing. 3) Annuli
survey. 4) Landing base inspection. 5) Temperature survey. 6) Corrosion logging.
An application has been developed to streamline and automate the planning, scheduling, execution, data
validation and data posting process to ensure compliance with these best practices. This application provides
tracking capability of the surveillance program and initiates alert, notification and escalation to the responsible
entity at every stage of the surveillance process. The wells with identified integrity issues are flagged on a Well
Watch List and closely monitored until their issue is resolved. This surveillance program is reviewed and updated
every 2 years to reflect the advancements in surveillance technologies and capture any necessary modifications
based on arising field observations.
This paper summarizes the well integrity surveillance program applied in Saudi Aramco. It provides a workflow
of the well surveillance process and describes the automation application used to capture and track the program
implementation. The comprehensive strategy provided in this paper can be used as guidelines for maintaining the
well integrity of all well types worldwide.
Introduction
Well integrity continues to be one of the top issues concerning the oil and gas industry. According to recent
reviews of the industry incidents, statistics showed that major losses of the hydrocarbon and petrochemical
industries, more than 80%, were associated with asset integrity (1). Hence, this continuous concern increased the
focus on well integrity standards, guidelines, specifications, and related tracking systems. In line with this, a Well
Integrity Surveillance Program (WISP) was developed by Well Integrity Surveillance Guidelines and Best
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Practices (WISG&BP) team to effectively manage and control risks associated with well integrity issues.
The developed Well Integrity Surveillance Program (WISP) expansively specifies the standards of well integrity
surveillance frequencies and preventive maintenance activities. In addition, it establishes a comprehensive well
integrity surveillance guidelines that can be applied corporate wide to ensure wells’ safety and healthiness.
Different thoughts were considered when developing this program by engaging the input of different expertise
such as production, drilling, facilities, and data processing disciplines. Indeed, WISG&BP team performed
thorough review of internal and international operating instruction manuals, standards, workshop-reports, and
published literature.
WISP accounts for the varying fields’ locations, fluid types, and well designs that Saudi Aramco is operating.
This challenging variety broadens the well integrity system and practices. Table-1 shows the different operating
environments, well types and designs in Saudi Aramco.
Literature Review:
Varying management systems for well integrity can be clearly observed in the different operating companies. All
of these systems are targeting same objectives; however, they have different scopes and strategies depending on
working environments and operating conditions.
Through investigation of several integrity systems, well integrity strategies must enhance the following:
Change of management
Continuous risk management and hazard evaluation
Protective systems
Incident investigation and prevention
Emergency management
Well integrity challenges to obtain a balanced scope of work between safety, reliability, and cost still exist in
many operating companies and organizations. Followings are the most encountered challenges and difficulties in
well integrity practices and operations:
Environment (rough weather, hurricanes, earthquakes, … etc.)
Human errors
Communication
Assets aging
Corrosion
Completion failures and errors
Solutions to overcome such challenges are proposed and can be achieved through following:
Management support at all stages
Risk analysis and assessment
Full awareness and involvement of every individual
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Above strategies, challenges and solutions are the result of different operating companies in the world. Several
companies stated above elements and considered them thoroughly when designing a well integrity management
system. WISG&BP team studided this carefuly to build and optimize the WISP.
WISG&BP team defines six (6) pillars for well integrity surveillance. The type of fluid (oil, water or gas) is the
primary dominant variable in WISP since it governs the level of operations and wells’ designs or specifications.
Frequencies of each pillar are proposed thoroughly to strike the right balance between safety, reliability,
efficiency and cost.
Wellhead Valves Integrity Testing and Greasing is an integral part of WISP, which is carried out on oil, water and
gas wells. This survey assures the integrity of the wellhead valves (i.e., Crown Valve, Master Valve and Wing
Valve) in addition to the Choke Valve, Plot Limit Valve and Isolation Valve.
Wellhead valves integrity testing has to be performed to guarantee the ability to control the well when required.
This survey should ensure that the valves are capable of isolating and holding the fluid flow and pressure at all
time.
Oil wells
Water wells
Gas wells
During Wellhead Valve Integrity Test, portable pump should be used for wells with zero pressures. In case of
finding a passing valve, the valve needs to be greased or replaced. This test should be conducted before any well
intervention job or workover operation.
The frequent maintenance of valves will reduce friction, corrosion induced damage, debris accumulation, sludge,
etc. by minimizing direct contact of valve components with the crossing fluid. Valves’ cycling is considered part
of the maintenance, because it moves valve components and break accumulations in the valve cavities. Excessive
cycling requires frequent greasing as it will wear the valves out relatively quickly. In addition, gears are the main
component of the valve and should be maintained in good condition to ease valve rotation.
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Oil wells
Water wells
Gas wells
Mechanical Lower Master Valve (MLMV) should be greased and cycled once a year.
Surface and subsurface safety valves are hydraulically actuated through an Emergency Shut-Down (ESD) System.
The surface valve is installed as part of the Christmas-Tree while the subsurface safety valve is installed around
300 ft. below the wellhead. These valves are installed to ensure well closure in any emergency situation, which
can vary from leaking flow-line to highly erosive, sand-laden fluid flow from the well.
The integrity and functionality of the SSV, SSSV and ESD systems should be tested on a quarterly basis for all
wells except high pressure gas wells and wells completed with ESP, to ensure that they are operable and can
perform their intended function. High pressure gas wells’ SSSV should be tested twice a year and ESP completion
wells should be tested in conjunction with the ESP trips with a minimum requirement of two times per year. In
case the valve failed, the well should be shut in and the valve should be replaced immediately.
3. Annuli Survey
WIGS&BP team proposed to maintain a positive pressure in the Tubing Casing Annulus (TCA) of all wells. This
will ensure that the TCA is filled with inhibited diesel or water and will enable quick detection of casing leaks.
In addition, all wells which are equipped with online pressure transmitters should be monitored on real-time all
the time. A snapshot of the annuli pressure of these wells should be captured and logged in the data base on a
quarterly basis and whenever the well status changes from shut-in to flowing or the opposite. The accuracy and
functionality of the annuli pressure transmitters should be verified every year using mechanical or electronic
pressure gauge.
Oil wells
All annuli of oil wells should be surveyed annually under flowing and shut-in conditions. This will enable
proper analysis and identification of wellhead or downhole communication. Exceptions:
Wells located in populated areas should be surveyed twice per year both under flowing and shut-
in conditions.
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Water wells
All water well annuli which have tubing (TCA) should be surveyed twice per year. This schedule ensures
the tubing integrity, as water produced or injected can be very corrosive.
Annuli of tubing-less wells should be surveyed annually because they are cemented.
Gas wells
Annuli of gas wells equipped with pressure sensors can be continuously monitored in real-time.
It is very important to survey every well after drilling or workover operations before initial production and within
one week after initial production. This is needed to capture the fluid expansion effect. In some cases, the
frequency might increase based on engineering judgment.
This inspection assures the integrity of the landing base and the surface casing of a well. New wellheads
completed by Drilling and Workover, should have their landing bases, surface casings and conductor pipes
coated. This will be considered as the first Landing Base inspection on any well. The subsequent inspection will
consider this as the starting date. Operation Engineering is responsible for initiating requirements for the existing
wells.
Oil wells should be inspected after rig release and once every 10 years. Wells with 30 years or more should be
inspected once every 5 years.
Water wells should be inspected after rig release and once every 7 years. Wells with 21 years or more should
be inspected once every 4 years.
Gas wells should be inspected after rig release and once every 10 years. Wells with 30 years or more should
be inspected once every 5 years.
5. Temperature Survey
The purpose of temperature survey is early detection of casing leaks and/or fluid movements behind pipe, which
can result in contamination of aquifers, loss of oil production or even surface blow-outs. Whichever occurs will
affect the profile of the temperature gradient recorded for that particular well. Timely identification of casing
leaks is critical to avoid the loss of hydrocarbons and contamination of shallow aquifers. It is important to
establish base temperature profiles, which will reflect these influences for each area. A base temperature profile
will provide a geothermal gradient of the area that can be compared with subsequent profiles. Base temperature
profiles should be recorded in all new wells before they are placed in production or injection, if possible. These
profiles in most fields will be similar enough from well to well so that a model geothermal gradient can be
established for each area. If a base temperature profile is not available for a particular well being surveyed, base
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In general, a base survey should be conducted for all (oil, water and gas) wells equipped with downhole packers.
Additional surveys are required as follows:
Oil wells
Wells older than 7 years but less than 13 years should be surveyed 3 times per year.
Wells that are completed with corrosion resistance alloy (CRA) across corrosive aquifers should be surveyed
twice per year.
Wells that are equipped with downhole packers — with known communication problems between reservoirs
below the packer — should be surveyed twice per year.
Wells that are completed with U/H packer and ESP should be surveyed in conjunction with ESP trips.
Water wells
Gas wells
6. Corrosion Logging
Corrosion logs are run to assess the integrity and thickness of the casing and to determine the location of casing
leaks. High resolution corrosion logs can survey triple casing strings (3-1/2", 7" & 9-5/8") and evaluate the total
metal loss (i.e., casings integrity). These can be used to establish a casing integrity baseline.
Oil wells
Representative Wells should be selected in all producing fields in Saudi Aramco to be logged through
tubing or during their workover, to establish the rate of corrosion in every field (or area within a field).
Based on the rate of corrosion and nominal thickness of the pipe, a logging frequency should be set as
follows:
Calculate the Remaining Casing Life (RCL) by dividing the total metal thickness by the
rate of corrosion (for wells with Remaining Casing Life exceeding 20 years, assume 20
years of Remaining Casing Life).
Run corrosion logs based on the number of years identified by dividing the RCL by 4.
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Run corrosion logs based on the number of years identified by dividing the RCL by 4.
Water wells
Representative wells should be selected in all producing fields in Saudi Aramco to be logged to establish
the rate of corrosion in every field (or area within a field).
Based on the rate of corrosion and nominal thickness of the pipe, a logging frequency should be set as
follows:
Calculate the Remaining Casing Life (RCL) by dividing the total metal thickness by the
rate of corrosion (for wells with Remaining Casing Life exceeding 20 years, assume 20
years of Remaining Casing Life).
Run corrosion logs based on the number of years identified by dividing the RCL by 4.
Run corrosion logs based on number of years identified by dividing the RCL by 4.
Run corrosion logs based on number of years identified by dividing the RCL by 4.
Gas wells
Casing Inspection:
Identify key wells for running casing inspection logs during workover operations scheduled every
year. Representative Wells should be selected from different areas of different field’s geography
and different geology. The casing should be evaluated with either an electromagnetic or
ultrasonic log, whichever is most appropriate. Perform runs without tubing in the hole to evaluate
the maximum number of casing strings. Based on findings, the casing monitoring program will
be adjusted to ensure wellbore integrity is maintained.
Tubing Inspection:
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Sweet Wells: Run the Multi-Finger Caliper Tool (MFCT) to detect any sweet gas corrosion as
follows:
Run MFCT base log on all new sweet gas wells before producing the well.
Run MFCT after a maximum of 3 years after the base log or as soon as formation water is
detected, whichever comes first.
Determine the rate of corrosion and calculate Remaining Tubing Life (RTL).
For wells with no formation water, Run MFCT at 1/3 of calculated RTL
For wells with formation water production, run MFCT every 3-12 months depending on
the chloride level of the formation water.
Conduct this monitoring program as long as the metal loss is less than 50%. If the metal
loss is more than 50%, confirm the presence of leaks. If a leak is present, workover the
well. Otherwise, continue monitoring the well quarterly.
It is very important to mention that if the Remaining Casing Life is less than 4 years of an oil, water, or gas well,
then a workover operation should be planned.
Well integrity practices must involve clear cycle of planning, scheduling and execution. These jobs are performed
to ensure safe operations by evaluating surface and subsurface data.
Since execution of such jobs involves huge operational cost and demands multidepartmental collaboration,
WISG&BP team is planning to enhance the visibility of the complete End-to-End processes for Planning,
Scheduling, Execution, Data Collection, Data Validation and Data Posting for better operational efficiency across
the organization (Figure-1). All the processes require a smooth coordination between various intra- and
interdepartmental stakeholders, timely availability of logistics, business critical decisions, and dissemination of
valuable information across the organization. It also requires standardizing the processes and unedifying data
models for all operation areas.
Planning
During this phase, a surveilance plan is being initiated, taking into considerations the available resources,
manpower, and logistics to conduct the different integrity jobs. Moreover, a priority breakdown will be shown to
operate accordingly.
Scheduling
Scheduling of planned well integrity jobs is a vital process in WISP. This would provide the actual date,
manpower and material requirements for job execution. Scheduling starts with analyzing the job requirements,
prepare list of the required materials, allocate job to the executing team, tie up for logistics, arranging
transportation, handling budgets and other intradepartmental coordination. Proper scheduling optimizes the usage
of available resources, logistics, and reduce time and cost. Well integrity scheduling process is initiated by the
operation engineers in a monthly basis.
jobs. The reports of the entire completed jobs are collected at this stage for analysis. Results of the analysis are
further processed at a later phase. Brief descriptions of the activities performed by operator, job coordinator,
support engineer and laboratories must be reported.
WISP incorporates a developed a Well Problem Watch List Application. The Well Watch list application (Figure-
2) has been developed with notification message and escalation capabilities to highlight problematic wells and
required actions. The Well Integrity Health Index reports showing different KPIs for the activities were also
created to help engineers and management in the tracking of data entry statistics, compliance and problematic
wells related to integrity issues.
These major enhancements significantly assist concerned Upstream Organizations to efficiently capture, monitor
and validate related data in the corporate well database. This feature also can highlight Saudi Aramco’s
problematic wells to management for timely corrective actions, thus alleviating any unsafe well situations.
This application provides data to Operations to track, facilitate, coordinate and report Well Problems related to
Well Integrity. The system will track all problems and planned actions, as well as escalating delays.
The GIS for Well Integrity (Figure-3) is a Geographic system that integrates, analyzes, shares, and displays
geographic well location with problems such that the Process Engineer/Management can focus on wells which
require special attention for the Petroleum Engineer/Management. The well integrity could be impacted by factors
like High pressures in Temperature surveys, Wellhead valve issues, etc.
Conclusion/Recommendation
• The increase of integrity concerns in the oil and gas industry over the years triggered the attention of
operating companies to modify and design an integrity program that can cost effectively lower the percent
of losses.
• Since this integrity program (WISP) takes into consideration different well types, completions, and
locations, it can be applicable corporate wide to be utilized by different operating companies.
• WISP provides a detailed specification of six well integrity pillars. Following these guidelines can
significantly increase the life cycle of wells and optimize asset integrity. It is very important to mention
that continuous and thorough update of the integrity program is needed periodically. This is to adequately
include possible changes, dependant on the review of integrity cases and events.
• It is very important to incorporate any integrity and surveillance program with an integrated tracking
system. WISP is being tracked and assessed through several integrity tools such as the Well Problem
Watch List Application, GIS Well Integrity Watch, and Scheduling Well Activity Tracking (SWAT)
system. These applications demonstrated its efficiency in managing the designed well integrity practices.
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Acknowledgment
The authors would like to thank and acknowledge Saudi Aramco; Northern Area Production Engineering and
Well Services Department (NAPE&WSD) Technical Review Committee and management for their permission to
publish this work.
References
1. “Large Property Damage Losses in the Hydrocarbon-Chemical Industries,” Marsh’s Risk Consulting Practice, 2003,
USA.
2. Esaklul, k., Al-Adsani, A., 2006; SPE 98190 – Integrity Management in KOC
3. Jones, J., Ariffin, A.; SPE 27287 – Implementing Operations Integrity Management System (OIMS)
4. Wallace, G., Kiddie, N., Kearns, J., Robinson, P.; SPE 115585 – A Compliance-based Approach to Well Integrity
Management
5. Haga, J., Corneliussen, K., Sorli, F.; SPE 120946 – Well Integrity Management: A Systematic Way of Describing
and Keeping Track of the Integrity Status for Wells in Operation
6. H. A. Al Muailu, S. Al Syed, K. Al Omairen and K. Al Yateem; Saudi Aramco, SPE 164425 – Systtematic
Approach to Integerate a Comprehensive Surface and Subsurface Well Integrity Management System
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