Well Integrity Resources

Standards -
NORSOK D-010, "Well Integrity in Drilling and Well Operations, Revision 3, August 2004" A free document, published by the Norwegian standards body. Comprehensive discussion of barrier system requirements for wells.
API Documents - these documents can be downloaded from the API web site or from the IHS web site.
API 6A: "Specification for Wellhead and Christmas Tree Equipment"
API 6AF: "Technical Report on Capabilities of API Flanges Under Combinations of Load" Analysis of flange loading including bolt makeup (pre-load), internal pressure, tension and bending moment. Pertinent to evaluating loads and bending moments imposed on trees.
API RP 14B: "Design, Installation, Repair and Operation of Subsurface Safety Valve Systems"
API RP 14C: "Recommended Practice for Analysis, Design, Installation, and Testing of Basic Surface Safety Systems for Offshore Production Platforms"
API RP 14E: "Recommended Practice for Design and Installation of Offshore Production Platform Piping Systems"
API RP 14H: "Recommended Practice for Installation, Maintenance, and Repair of Surface Safety Valves and Underwater Safety Valves Offshore"
API RP 57: "Offshore Well Completion, Servicing, Workover, and Plug and Abandonment Operations"
API RP 65: "Cementing Shallow Water Flow Zones in Deep Water Wells"
API RP 90: "Management of Sustained Casing Pressure on Offshore Wells" Guidelines on managing wells with sustained casing pressure on an annulus
TR9501, Rev A: "Specification for Stud Bolts and Tap End Studs" Association of Well Head Equipment Manufacturers, 11 June 2002. This AWHEM Recommendation establishes definite dimensions for stud bolts and tap end stud for use wth API Spec 6A flanges/studded flange connections and provides for dimensionally interchangeable stud bolts and tap end studs for API Spec 6A flanges/studded flange connections.
SPE Resources & Papers - SPE web site, "OnePetro" web site
SPE Distinguished Lecturer Presentation: "Implementing a Well Integrity Management System"

Spanish-language version
This presentation was presented during the 2007-2008 SPE Distinguished Lecturer season
SPE 130428: Sealing Casing Leaks through the Remote Deployment of Discrete Particles
SPE 130395: Case Study: Shallow Surface Casing Corrosion Mitigation Evaluation
IPTC-13405-MS: Well Integrity Management Systems; Achievements versus Expectations Managing well integrity is essential to economically develop oil and gas resources while preserving the environment and assuring safety to personnel.

The industry accepted definition of well integrity management is the application of technical, operational and organizational solutions to reduce the risk of uncontrolled release of formation fluids over the entire lifecycle of the well. (NORSOK-D010)
Well Integrity assurance on the other hand is to ensure the availability and functionality of at least two well barriers during its drilling, production and abandonment phases.

The current worldwide focus is on the development of systems and processes to manage the well operations and interventions to assure well integrity with many claims to have a workable system that verifies and confirms the status of wells with suspect integrity.

The basis for well integrity management systems can be categorized as:
  • R & D oriented systems that are built around the development of technical solutions to well construction and operational problems. For example, the development of new inspection logs, cements, materials, equipment and techniques.
  • Statistically driven, those are based on the study of the historical failure frequencies and the assessment of associated risk.
  • Well pressure monitoring and assessment and wellhead maintenance.
  • Reservoir model based system that takes into consideration the reservoir development to ensure well integrity throughout the field development and production life.
In this paper different well integrity management systems were reviewed against worldwide industry expectations for a system that can manage well integrity that starts at the exploration phase and continues through its abandonment.

SPE-129083: Well Integrity Issues in Malacca Strait Contract Area Summary: The Malacca Straits contract area is located on the east of Sumatera Island between Sumatera and the Malaya Cape. This area started oil production in the early 1980’s, and consist of 175 onshore and offshore oil wells spread over five fields, namely the Kurau, Melibur, Selatan, Lalang, and Mengkapan oil fields.

A 7.9 Richter scale earthquake occurred on 12 September 2007. The epicenter of the earthquake was 159 KM south west of Bengkulu, a province in the southern part of Sumatera. Two days later, during a snubbing unit service on the K-02 well, the 9-5/8” casing suddenly dropped down six feet. It was believed that the area had been impacted by the earthquake since another snubbing unit found lateral movement on wellhead while doing workover on nearby well. Following the incident, the well services team inspected the K-02 well and found it had an integrity problem.

This finding lead to a wider investigation, which revealed that other wells also suffered integrity problems, including unsecured wellheads, leaking wellheads and christmas trees, severe corrosion of well components, failure of cement bonding, and casing elongation / casing drop due to top soil compaction / reservoir subsidence. At this point, it was decided to initiate a comprehensive well integrity study.

The integrity problems are due to several causes: wells exceeding their design life (most wells were constructed in the mid to late nineteen-eighties), exploration wells being used as producers without improvement, environmental degradation from deforestation (drop in the water table causing top soil compaction), and more than twenty years of production (causing formation subsidence).

This paper details the well integrity study, including the well assessment, the evaluation of well operation in term of safety, environment and profitability, and recommended effective temporary remedial actions.
IPTC-12624-MS: Optimizing Well Integrity Surveillance and Maintenance Managing well integrity is essential to economically develop oil and gas resources while preserving the environment and assuring safety to personnel. ExxonMobil Exploration & Production Malaysia Inc. (EMEPMI) operates 17 offshore oil and gas fields in the Malay Basin. EMEPMI performs well integrity operations and maintenance on 37 platforms involving 781 wells with 1215 completions (single and dual wells). There are about 350 wells on gas lift, 1215 surface controlled subsurface safety valves (SCSSV), with 6943 tree and wellhead valves. The fields produce approximately 150,000 bopd and 1.2 BCFD of gas.
 
In this mature asset, many wells were previously un-competitive or uneconomic to flow. In today’s higher-price environment, all wells are being re-evaluated for their production contribution. This paper describes the issues and actions taken for these “moth-balled” idle wells to ensure that they comply with the EMEPMI well integrity surveillance and maintenance standards for offshore platform facilities. At the same time, the effort was broadened to check and ensure the integrity of all active completions. The EMEPMI well integrity surveillance and maintenance standards are based on API and industry standards, as well as the global ExxonMobil well integrity standards.
SPE 125712: Well Casing Integrity Excellence: A Case History of Evaluating Casing Integrity Using Modern Imaging and Corrosion Tool Logs in Ghawar Field in Saudi Aramco Ensuring good casing integrity is very important to prolong well life. Cement quality is a major element for ensuring casing integrity. Well casing integrity excellence is the key aspect that makes a well in good condition and keeps the well completion suitable to produce crude oil from an oil producer or inject water in an injector.

Recently, advances in cement and well completion practices have significantly improved the quality of wells and extended their operating life. Also, the installation of a Cathodic Protection System (CPS) on every well, and tubing packer completion in some wells, prevented external corrosion and consequently casing failure. However, casing integrity problems were discovered in three isolated cases. This paper will discuss issues related to three wells where casing leaks or behind casing channeling were detected across a high-pressure zone located above the main reservoir. A team, consisting of professionals from various engineering departments, was formed to explore remedial options and techniques, as well as employ tools and new technologies that assess well casing integrity excellence. Implementing the recommendations and findings of this team have improved well casing integrity.

As well casing is an important asset to ensure well safety, continuous operation and environmental protection; there is an ever increasing need for tools that verify wells with suspect casing integrity problems. These tools are the Cathodic Protection Evaluation Tool (CPET), Ultrasonic Inspection Tool (USIT), Ultrasonic Corrosion Inspection Tool (UCIT) and the Electro-Magnetic Imaging Tool (EMIT). The EMIT provides real images of the multiple casing strings.

CPET, USIT, UCIT and EMIT were selected and run on three wells Well-A10, Well-A20 (oil producers) and Well-B1 (water injector) with suspected casing integrity problems. These logs detected and imaged the corroded, scaled and cracked intervals before performing remedial actions to return the wells to an operating status by renovating casing integrity.
SPE 123201: A Systematic Approach to Well Integrity Management A discussion of Marathons implementation of the Expro WI management software in the North Sea. Recognising the importance of good well integrity management practices, Marathon Oil UK developed an online database in conjunction with Expro to capture their well integrity data. The database has become a focal point to help facilitate Marathon’s well integrity management processes and philosophies. The aim of this paper is to provide an overview of the rational for developing the system and the benefits that are being realised for both the Brae and Alvheim assets.
SPE 120978: Pressure Activated Sealant Economically Repairs Casing Leaks on Prudhoe Bay Wells Pressure activated sealant was used to repair casing leaks in two Prudhoe Bay, Alaska oil wells without the use of a rig workover. The significance of the treatments, development of job screening criteria, and job planning and execution are reviewed.

Production casing leaks are a frequent problem in mature oil fields, particularly where there is corrosion. Wells with casing leaks usually do not meet well operating criteria so they must be shut-in, causing a loss in valuable production. Casing leaks normally require a rig workover to repair since the tubing often has to be removed. Rig workovers are very expensive in offshore locations, remote areas, and harsh climates. Special pressure activated sealants, diagnostic tools, and treatment techniques have been developed to find and repair casing leaks without removing the tubing.

Case studies of three Prudhoe Bay production wells describe how pressure activated sealant successfully repaired the small casing leaks in two wells without removing the tubing. The third well was not treated because it did not meet the screening criteria. One case study was unusual because the sealant fixed four deep casing leaks with one treatment.

The case studies show how refinements in diagnostic techniques, candidate screening, and treatment planning and execution have resulted in the successful application of pressure activated sealant to repairing casing leaks in producing wells and in one case repaired four leaks with one treatment. Using pressure activated sealant to repair casing leaks can result in significant cost savings and return wells to production sooner. The treatment can be particularly useful in mature fields with corrosion problems and in offshore, remote, and arctic fields where rig workovers are expensive and rig availability is limited.

SPE 120946: Well Integrity Management: A Systematic Way of Describing and Keeping Track of the Integrity Status for Wells in Operation Talisman operates several fields on the Norwegian Continental Shelf (NCS), many of these mature fields are taken over at the end of their design life. These old fields represent challenges with respect to well integrity and overall profitability.
Talisman is a member of the Well Integrity Forum (WIF), a co-operative effort between the operating companies on the NCS to define a unified approach for handling well integrity. Using WIMS and the WIF recommendations together with internal guidelines improves Talismans ability to handle well integrity issues throughout the production phase of a well and in compliance with regulatory requirements.

This paper describes how Talisman Energy Norway (Talisman) manages well integrity for their assets, and discusses the benefits, challenges and lessons learned from implementing a well integrity management system, focusing on technical and organizational aspects.
SPE 120495: Implementing a Well Integrity Management System This discussion defines “Well Integrity” and presents the framework used by BP to implement and manage well integrity programs. Well integrity has received increasing attention from all aspects of the petroleum industry, from well design and construction to operations, maintenance and well abandonment. Factors driving this attention include a desire to ensure wells remain viable in fields with long lives, maintenance of company reputation and avoidance of litigation. Confusion regarding the definition of well integrity can make it difficult to create a holistic approach to implementing a management system.
SPE 117121: The Total Control of Well Integrity Management This paper describes a web-based program which provides a comprehensive approach to well integrity management covering all potential integrity threats to the whole well. This “cradle-to-grave” software, the Intetech Well Integrity Toolkit (iWIT), provides well information and data analysis for timely, informed, decision-making. Using its own or existing client databases, this software carries out quantitative data analysis in real-time and provides feedback to the operator about the condition of individual wells and also overviews of the whole field integrity status.
SPE 116771: Prudhoe Bay Well P2-15 Surface Casing Failure
SPE 116765: Analysis of Thread Engagement Requirements for Studs and Nuts
SPE 115585: A Compliance-Based Approach to Well Integrity Management This paper describes a process for actively managing well integrity throughout the development life cycle with a particular focus on the production operations / well maintenance phase. Although developed in relation to ConocoPhillips UK North Sea development wells, most of the features of the process have application to all development well operations (both onshore & offshore) under any regulatory regime.

The original well integrity management process was developed in order to demonstrate compliance with the UK Offshore Installations & Wells (Design & Construction, etc) Regulations 1996 (DCR). Since that time the original process has continued to be modified to improve effectiveness & efficiency. As well as describing the current process, this paper also describes its development and how we see that the process might evolve in the future.

DCR regulations form a part of the UK ‘safety case’ regime. The ‘safety case’ regime places a strong focus on the development of site-specific performance standards; it also utilises the principles of independent examination & verification in order to demonstrate compliance. The process described in this paper represents a significant new contribution to the management of major accident hazards in well operations since it focuses on the use of performance standards and independent examination in order to ensure well integrity.
SPE 114911: Real-Time Well Diagnostic Using Slick-Line Fiber-Optic Distribute Temperature Sensors: West Venezuela Applications
SPE 112872: Trapped-Annular-Pressure Mitigation: Spacer Fluid That Shrinks - Update Discussion of a field trial in a 9,800-ft-deep gas well of a water-based polyymerization shrinks 20%, mitigating trapped annular pressure (TAP).
SPE 110347: Well Integrity Management System (WIMS)—A Systematic Way of Describing the Actual and Historic Integrity Status of Operational Wells It is important to be able to have an overview of the well integrity at all times. Statoil, Norsk Hydro and Total E&P UK Ltd. therefore joined forces in a JIP with ExproSoft to develop a software application for data collection, handling and reporting of well integrity. The resulting software is called WIMS, short for Well Integrity Management System. A pilot version was installed and tested by the operators’ spring 2007, prior to the release of the final version.
SPE 108906: "Detecting Ultra-small Leaks With Ultrasonic Leak Detection-Case Histories From the North Slope, Alaska" An ultrasonic leak detection logging tool conveyed on electric line, and recently on wireline in memory mode, has been introduced which can detect leaks as small as 1/2 cup per minute. This revolutionary tool has been used to accurately identify leaks in tubing and behind pipe. Wells that otherwise would immediately be slated for a rig workover (RWO) have been repaired with non-rig solutions.
SPE 108698: "Well Integrity Assurance: A Successful Method for External Corrosion and Damage Detection on Outer and Middle Concentric Strings of Casing"

SPE Presentation.pdf
SPE 108195: "Locating and Repairing Casing Leaks with Tubing in Place - Ultrasonic Logging and Pressure-Activated Sealant Methods " When operators are faced with issues involving casing leaks, a typical course of action is to pull the tubing and make efforts to identify and locate the source of the leak by logging or other mechanical means. If the leak source can be successfully located, a mechanical method is generally employed to patch the leaking casing. This methodology is time consuming and expensive.

Locating casing leaks with the tubing in place using conventional logging techniques has historically been difficult. Where some tools, such as temperature tools, may provide an indication of an anomaly in annuli, the data may be subjective or the leak may be too small to measure. When active, a leak will produce a spectrum of sonic frequencies that may be either audible, ultrasonic or both. Ultrasonic energy will pass through steel but travels relatively short distances. A tool developed around these principles has been successful in accurately locating casing leaks behind tubing.

Pressure-activated sealants have been used for a number of years to cure a wide variety of leaks in casing, tubing, control lines, and well heads as well as micro-annulus leaks in cement. For the purpose of repairing a casing leak behind tubing, the liquid sealant may be pumped into the annulus and displaced to the leak site. The liquid sealant will not polymerize until it is exposed to the differential pressure through the leak site. Knowing the leak rate, pressure and precise location of the leak aids in the selection of the sealant formulation and deployment method. This helps to reduce overall repair cost as well as increase the probability of a successful repair.

This paper will describe the ultrasonic method of leak detection and the method of curing leaks with pressure activated sealant with tubing in place. Case histories will be presented where these methods were employed to repair casing leaks without removing the tubing.
SPE 106533: "Rigless Installation of Safety Valves To Implement a Well-Integrity Campaign and Return Wells to Production" Protecting the environment and health of the people by ensuring the integrity of all wells is one of the must-obey policies in Shell Petroleum Development Company of Nigeria Limited (SPDC). SPDC has been the leading producer of crude oil in Nigeria for more than 50 years. SPDC produces from many brown fields. SPDC currently has an inventory of producing wells that have been shut in because of one form or another of wellbore integrity problems. In some cases, these wells were completed decades ago when HSE requirements were considerably less stringent than they are today and wells were completed without sub-surface or downhole safety valves.

In 2003, a more stringent policy on non-integrity wells was introduced and led to an investigation of service providers for a more reliable rigless installation of safety valves or a more cost effective rig workover. However, most of the brown fields that encompass these wells are predominantly located in the Niger Delta both in the shallow waters offshore and in land locations including swamp areas. Many of the wells are located on small-unmanned production jackets which do not have the structural integrity to support even an electric line unit let alone a workover rig. In addition the current geopolitical situation in the Niger Delta is such that bringing in any heavy-duty equipment can be extremely difficult and highly uneconomical in most of these low producing wells.

It was against this background that SPDC carried out a well integrity management campaign to examine the feasibility of some kind of economic intervention to bring these wells back onto production.

In this paper the authors will examine in detail the prevailing situation, present details of the alternative solutions that were considered and describe a highly economic campaign that was put in place to rehabilitate some 40 wells and make available some 30,000 bopd of oil production, all without the use of major workover equipment.
SPE 105319: "A Comprehensive Approach to Well-Integrity Management in ADMA-OPCO" The last few years have seen a renewed emphasis on Well Integrity (WI) worldwide, and ADMA-OPCO in particular.
ADMA operates, more than 600 wells, in two offshore fields, which include oil producers, water injectors, gas producers/injectors and observation wells. A dedicated team was setup to focus entirely on WI and related issues. The team was given the objective to achieve the following.

- Determine the Well Integrity Status of the entire well stock through risk review and ranking.
- Recommend appropriate action plan for each well with unacceptable level of risk.

The team used a comprehensive and novel approach for handling this project. This paper is a case study of the methodology adopted by the team to achieve this task.

Since the main objective was to risk review and rank the entire well stock, a dedicated risk-ranking process was designed, which served as an automatic guide to risk review and ranking of wells. The industry Risk Ranking matrix was modified to make it more objective and easy to use.

It soon became obvious that risk evaluation of wells was only possible based on availability of good data organized in a user-friendly format. A dedicated database was setup in parallel with other activities. The web-based database was designed to contain all the data required for WI review of any well and is capable of tracking well integrity related tasks automatically.
Well Integrity data included well construction, annuli pressures, production, well intervention, etc. The data existed in the office files were promptly transferred into the database.
SPE 102815: "Applied Ultrasonic Technology in Wellbore-Leak Detection and Case Histories in Alaska North Slope Wells"
SPE 102524: "Well Integrity Operations at Prudhoe Bay, Alaska" This paper discusses the well integrity management system used at the Prudhoe Bay field located in Alaska. The focus is on systems and processes implemented to manage the well operations and interventions phase of a well’s life.
SPE 101888: "Gate Valve Drilling/Milling Operation on the North Slope, Alaska" Milling out a gate valve is a very tedious operation and could be risky if the proper well control and procedures are not put in place. 
SPE 101398: "Restoring Well Integrity in a Critical Gas Pilot Injection Well" Appearance of abnormally high pressure in the 9 5/8” X 13 3/8” casing annulus of a pilot gas injection well located offshore Abu Dhabi, alerted staff to a potentially serious situation from both safety and economic viewpoints. The subject well is a critical component of a pilot project to test the effectiveness of gas injection towards improving oil recovery. Based on this and other data, decisions on long-term reservoir development involving considerable investment will be made. The well was drilled and completed in 1999 as dual gas injector into two, Lower Cretaceous limestone reservoirs and put under gas injection in 2001. Abnormally high pressure was observed in the 9 5/8” x 13 3/8” annulus after three months of injection. A multidisciplinary task force was formed with a mandate from senior management to locate the source of leaking gas, the communication path to surface and recommend remedial actions. A risk assessment ranked the danger to the 80 million U.S. dollar platform and personal as high. As a result, gas injection was halted and visits to the platform minimized. Evidence gathered from the well records and newly acquired diagnostic logs suggested the existence of poor or no cement behind the 7” liner and 9 5/8” casing providing a conduit for gas to surface. Moreover, the existence of two abandoned holes penetrating the shallowest reservoir and located at short distance from the currently active bore hole were recognized as potential pathways for gas to surface. Extensive remedial cementing operations were performed including: (1) block squeezes behind one and two sets of production casing above the source reservoir, (2) cement circulation squeeze between production and intermediate casings through mechanically drilled holes. The high annulus pressure was thought eliminated but soon returned after injection commenced. A decision was made to convert the nearby un-perforated Gas Observer to water injection for the shallowest reservoir and continue gas injection into the deepest reservoir of the original well.
SPE 100600: "Downhole Integrity Management in October Field, Gulf of Suez, Egypt”" The paper discusses historical data related to downhole scaling, corrosion and surveillance methods to identify affected wells. Efforts to minimize production impact due to increased corrosion seen late in the field life along with longer term corrosion mitigation efforts are also reviewed. Examples of how tubing was originally protected by thin film scale accumulation and emulsion flow during early field life production are also presented. Increasing October’s completion corrosion manageability is a key challenge facing the field. Addressing issues related to predicting future well failures and their associated production loss impact rig scheduling and procurement of expensive long-lead time completion material (Cr 13%).
The approved plan is to repair six wells per year over three years considering known well problems, remaining reserves, materials and rig availability. In early 2005, six well's were worked over and visual inspection of retrieved tubing showed an excellent match with caliper log data. The most severe corrosion is typically deep in the well and is related to high CO2 partial pressures. Corrosion risk to the casing has also been identified as potential issue and wall thickness assessments have been performed on some workovers. The paper reviews these items in greater detail and proposes forward plans for the remaining life of field.
SPE 98739: "The Snorre A Incident 28 November 2004: Lessons Learned"

PSA Investigation of Snorre Blowout
Statoil has carried out a comprehensive analysis of the underlying causes after a gas seabed blow-out on the Snorre field in the North Sea. On 28 November 2004, an uncontrolled gas blow-out took place on the seabed under the platform. The incident occurred in connection with the preparation of well P-31A for the drilling of a sidetrack. During pulling of a 2,578 m scab liner, gas was drawn into the well and it leaked out through a known hole in the 9 5/8" casing then through an unknown damage or weakness in the 13 3/8" casing.

PSA Report: On 29 November 2004, the PSA appointed an investigation group which has identified non-conformities and improvement areas. These can be categorized as follows: Lack of compliance with governing documents, inadequate understanding and implementation of risk assessments, inadequate management involvement and violation of well barrier requirements. The non-conformities occurred at several levels in the organization on land and on the facility. The investigation shows that the number of non-conformities and improvement areas is extensive. There is nothing that would indicate that the incident was a result of chance circumstances.
SPE 97863: "Managing Well Integrity, Safety, and Production Decline Caused by Scale" This work will describe the management of scale in a United Arab Emirates offshore carbonate reservoir. Field pressure is sustained by water injection, which contributes to the formation of scale in downhole tubulars. This scaling can cause both safety and production problems, for example, by blocking a subsurface safety valve or chocking flow at downhole nipples.
ZADCO has initiated a successful strategy to manage the sulfate-scaling tendency in the completion tubing. Software is used to identify wells early on as potential scale candidates. This software uses real field measurements and analysis of injected and produced water information. The results are used to plan well monitoring and/or treatment. The identified wells are monitored using both slickline gauge measurements to measure actual scale growth and produced water surface analysis to update the software model.
SPE 97597: "A Case History of Sustainable Annulus Pressure in Sour Wells – Prevention, Evaluation and Remediation" This paper describes evaluation of the possible causes of Sustainable Annular Pressure (SAP) in a sour gas field in the Middle East. It explains the diagnostic testing undertaken and describes how evidence was used to identify the cause of the SAP. The steps taken to prevent the occurrence of SAP in new wells and to remedy the problem in existing wells are described.
SPE 96337: "Want to Make Tree Operations Safer? Why Not Use the DHSV as a Barrier?" Industry practice for the design and operation of oil and gas producing wells incorporates a two-barrier policy, and defines an integrity envelope for environmental protection and safe operations. The standard practice when removing or undertaking major operations on the Xmas tree is to set one or more plugs in the production tubing to maintain two barriers between the reservoir and the environment.
This paper assesses the relative risk of using a Down Hole Safety Valve (DHSV) as a qualified barrier during such operations.
QRA has been used to assess the risks of an uncontrolled flow of fluid from the reservoir when using a qualified DHSV as a barrier as compared to the standard practice of setting one or more wireline plugs. Three representative cases have been considered in this study:
Case 1 examines changing valves downstream of the master valve on a sub sea well.
Cases 2 and 3 focus on platform wells.
Case 2: changing valves downstream of the lower master valve, and
Case 3: removing the Xmas tree.
The study shows that the major risk when using a wireline set plug as a downhole barrier arises from the blowout risk associated with wireline operations. Use of a DHSV as a qualified barrier eliminates the wireline blowout risk, and reduces the overall risk during Xmas tree operations. Hence, the study recommends the use of a qualified DHSV as a barrier, subject to a risk assessment on a case by case basis.
SPE 95813: "Enhancing Collaboration Between Engineering and Operations - A Case Study of Alaska Work Processes" This paper details the collaboration and well information system BP Exploration (Alaska), Inc. has implemented to enhance communication and data sharing between work groups operating the Prudhoe Bay field. Accessing and sharing well information and maintaining quality communication between geographically separate Operations and Engineering teams is an issue in all oilfield operations.
SPE 94427: "Northern Sahara Aquifers Protection: Casing Corrosion Problems and Defining New Well Construction Performance Objectives—Case Study: Hassi Messaoud Oilfield in Algeria" Well construction reliability is always of great importance especially when it is about drilling in an arid region that contains strategic groundwater reserves. This is the case of Hassi Messaoud and satellite oilfields (HMDs) in Algeria where aquifers of the Northern Sahara System (NSAS) Spread out. Problems closely related to well construction such as casing corrosion, cementing lack and also those of post-abandonment are encountered by Sonatrach and partners there.
SPE 91399: "Microannulus Leaks Repaired with Pressure-Activated Sealant" Sustained casing pressure is a serious problem that is prevalent in most of the oil producing regions of the world. Annular pressure can be a significant safety hazard and, on a number of occasions, has resulted in blowouts. Sustained casing pressure results from the migration of fluids in the annulus. The most common path for migration of fluids is through channels in the annular cement. To safely and economically eliminate sustained casing pressure on a well in the Gulf of Mexico, W&T Offshore, Inc. utilized an injectable pressure-activated sealant technology to seal channels in the annular cement of their well and eliminate the casing pressure. The mechanical integrity of the well was restored, saving over $1,000,000 compared to a conventional rig workover.
SPE 88934: "Well Integrity Management System in Shell Nigeria" Well Integrity is a vital aspect of well design, construction, operation, maintenance and abandonment. As put by SPDC, “all wells shall be designed, constructed, operated, maintained and abandoned in a manner that safeguards their integrity, minimize Health, Safety and Environmental risks and ensure their planned availability throughout their life-cycle”. As a consequence of this policy, all wells are monitored to ensure their integrity is guaranteed at all times. By implication all wells that fall short of standards are secured or closed-in unless a short-term deviation or waiver is granted.
Well integrity problems may occur in producing and non-producing wells, especially older wells that were completed as per the prevailing completion standard of their completion dates. The completion standards have changed over time with respect to safety requirements (e.g. wells without top packers, wells without SCSSVs). There may also be some wells that meet current safety standards but still have some integrity-related problems (e.g. leaking packer or silted well slots-swamp locations).
SPE 88696: "Well Integrity Management System (WIMS)" ZADCO owns more than 500 wells operating in UZ, UA & ST fields to contribute in achieving the production targets as set by the Shareholders. To ensure that wells operate as designed for their assigned life (or greater) with all risks kept as low as reasonably practicable or as mentioned, it is important to insure individual well's integrity. Hence, ZADCO developed an in-house “Well Integrity Management System (WIMS)”, which defines & provides the operating standards & guidelines for maintaining the well integrity parameters, ensuring safe well operations and securing well potential availability during its life cycle so that return on investment is maximized without the sacrifice of safety and environment.
The implementation of ZADCO's well integrity process follows the cycle assurance testing, preventive measures, monitoring, evaluation / assessment, control & remedy, audit / verification.
SPE 87198: "Remediating Sustained Casing Pressure by Forming a Downhole Annular Seal with Low-Melt-Point Eutectic Metal" Described are proof-of-concept developments to form a seal for mitigating sustained casing pressure caused by annular pressure buildup. Annular pressure can result from numerous sources, including tubing leaks, loss of isolation potential within the cement column because of poor mud displacement, free water-induced channels, stress fractures, and failure of the cement to cover all potential sources of annular pressure. In most cases, annular pressure is not observed at the wellhead until the well is placed on production, making it difficult to identify, access, or remediate the pressure source. A new and novel approach to remediation has been tested in which a low-melt-point alloy metal is dropped down the backside of the casing where annular pressure has been observed. The metal is allowed to accumulate at the top of cement or other physical barrier, melted with an induction-heating tool, and allowed to cool and solidify. This process forms an annular seal to stop fluid communication between the formation and wellhead.
SPE 84556: "Improved Techniques to Alleviate Sustained Casing Pressure in a Mature Gulf of Mexico Field" The objective of this paper is to highlight the techniques used during a recent workover program to alleviate sustained casing pressure in a Gulf of Mexico field. Discussion will include cement and workover fluid programs, hole preparation before milling and cementing operations, and improved milling procedures.
SPE 81002: "Acoustic Signal Analysis for Sand Detection in Wells with Changing Fluid Profiles" Discusses results of a study to predict sand production using acoustic meters.
SPE 67194: "Diagnosis of Sustained Casing Pressure from Bleed-off/Buildup Testing Patterns" When the casing pressure can not be permanently bled off through needle valves at wellhead, the casing is said to exhibit Sustained Casing Pressure (SCP). Since high values of SCP may threaten worker safety and environmental protection, MMS regulations require remedial treatment. Testing of SCP could provide information on parameters causing gas migration and SCP.
A mathematical model for testing SCP buildup has been developed. The objective of the model to identify the flow mechanism of external leak leading to SCP. The model also determines critical parameters of the leak to be used in selecting some remedial actions. Also presented in the paper are two examples of using this model to analyze actual SCP field tests. The analysis gives acceptable estimates of the depth of gas invasion zone, formation pressure, cement conductivity, and expected maximum value of casing pressure.
SPE 36913: "Risk Assessment of Hydrocarbon Releases during Workover and Wireline Operations on Completed Wells on Offshore Platforms " Safety Regulations in the UK require operators to demonstrate that the risks to workers from well operations on offshore platforms have been reduced to the lowest level that is reasonably practical. Each offshore platform in the UK has a safety case which includes a quantified risk assessment of well operation hazards with the potential to cause a major accident.
Assessment of the safety cases by the UK Health and Safety Executive (HSE) showed that few operators have specifically analysed risks resulting from well workover or wireline operations, regarding such risks as subsumed within general blowout risks. where workover/wirelining have been considered separately, the risk estimates have been determined from average worldwide historical hydrocarbon release frequencies and not by analysis of particular operations being carried out on a specific platform. The prevalent conclusion from such risk analyses is that the contribution of workover/wireline risks to the total platform risk levels is very small. In order to evaluate whether such a conclusion is necessarily valid in all cases, HSE undertook a study to establish a method for estimating workover/wirelining risks for a number of different types of platform.
SPE 23136: "The Occurrence of Annulus Pressures in the North West Hutton Field: Problems and Solutions" This paper discusses the occurrence of annulus pressures in the North West Hutton oilfield, offshore UK, and how the problems associated with these pressures have been addressed. Several wells have experienced annulus pressures in this field, where production is exclusively via gas lift. The causes of annulus pressures are discussed in the context of the mechanical configuration of the wells. An evaluation of the safety aspects and concerns associated with these pressures is then presented.
SPE 22871: "How to Design for Annulus Fluid Heat-up" Existing single-string analysis methods are inadequate for solution of heat-up problems, which require a global analysis of the whole well system (all casings together). This paper presents a method for such a technique, termed global service life analysis, and describes an FE program (ADHOC) developed to implement it. The formulation is fully general, and is applicable to a wide range of casing design problems.

Introduction: An earlier paper co-written with BP described a recent study into annulus heat-up stresses in subsea production wells. A new and rigorous theoretical model was developed, and used for the computer analysis of several case studies. The results showed that:
- annulus heat-up causes high burst/collapse stresses; - conventional design methods were inadequate for predicting these stresses.
However, limited space prevented any attempt to explain the analysis method. This paper presents the theoretical basis for the earlier work, and explains how this theory is applied in practice.
SPE 21727: "Methods of Detecting and Locating Tubing and Packer Leaks in the Western Operating Area of the Prudhoe Bay Field" Evaluation methods have been developed to detect cases of tubing/annulus communication. Temperature, spinner and noise logs, as well as fluid level detection equipment, are used under a variety of flow conditions. Step-wise procedures are provided.
SPE 178: "Helical Buckling of Tubing Sealed in Packers" Most gas wells and flowing oil wells are completed and treated through a string of tubing and a packer. Changes in temperature and in pressure inside or outside the tubing will: (1) if free motion of the tubing inside the packer is permitted, increase or decrease the length of the tubing; or (2) if free motion is prevented, induce forces in the tubing and on the packer. If pressure inside the tubing is greater than outside, the tubing may buckle helically even in the presence of a packer-to-tubing tension.
SPE XXXX: "Well Integrity Assurance: A Sucessful Method for External Corrosion and Damage Detection on Outer and Middle Concentric Strings of Casing"
IPTC-11678: "Design and Early Implementation of a Well Integrity Management System in an Offshore Brownfield Operation" A well integrity safety management system was developed and methodically implemented during 2005-07 in the Gulf of Suez, Egypt. The system is fit-for-purpose to meet the unique needs and capabilities of the organization. Methodical execution of the system was strategically planned and prioritized based on safety risks and business needs.
This paper provides a summary of the Gulf of Suez well integrity system development and deployment. Critical well integrity requirements were evaluated in a comprehensive well integrity study during 2005. Many existing well integrity practices were documented and formalized. Other outstanding requirements were identified and assigned a priority for implementation.
Existing Gulf of Suez wells were found to be in various conditions on well integrity, ranging from high to relatively low operating risk. Criteria for defining a “high risk” well were established and communicated throughout the organization. “High risk” wells were documented in a public register and shut-in if necessary to reduce operating risk. Also, a dedicated well services team was established to control and/or repair “high risk” wells on a full-time basis.
"Annular pressure buildup: What it is and what to do about it" Deepwater Technology, August 2000, by Bob Moe and Peter Erpelding. When tubing heated by hotformation fluids contacts colder fluids entrapped in the annulus, the result is fluid heating and pressure buildup. Proper well design is critical in subsea wells.
OTC 11029: "Sustained Casing Pressure in Offshore Producing Wells" /td>
   
MMS Studies  
"Risk Assessment of Temporarily Abandoned or Shut-in Wells", Project 99041, October 2000 An MMS sponsored study of the risk relating to temporarily abandened and shut-in wells.
"A review of sustained casing pressure occurring on the OCS" Report submitted to Minerals Management Service. Downloadable from MMS website, www.mms.gov/TubingStudy.
Vendors
Baker Tubing patches
Spidr Gauges Self-contained pressure and temperature recording device
Pioneer Petrotech Services Inc. (PPS) is a global leader in the development and manufacturing of high quality pressure and temperature gauges for oil and gas industry. Our innovative electronic technology has enabled us to offer robust 200 deg.C gauges for assisting oil companies to explore oil reserves in deep water areas. The easy to use software has made gauge operator's job a lot more productive and simpler. Our mission is to help world wide customers acquire accurate reservoir pressure and temperature data in all different well conditions. PPS 31 - Wellhead Pressure Logger The PPS31 is a wellhead digital pressure and temperature monitoring gauge. The application of radio transmission allows operators to receive real-time data which is also stored in the memory chip in the logger. Pressure and temperature can also be directly read from the LCD (liquid crystal display). The intrinsically safe design permits the logger to be used in critical environments.
Canada Tech Our Surface Logger is a surface pressure gauge which displays data in real-time. The Surface Logger operates as a memory recorder or a real-time, short-range wireless pressure transmitter.

With regular usage, a battery has a life of 1 to 2 years. Sample rates are programmable and the Surface Logger displays pressure and temperature in various units as determined by the user.

The use of Canada Tech’s Firmware version 1.6 or greater will allow the Radio Surface Logger to function as a memory recorder and a wireless pressure transmitter when set to Log Mode. The Radio Surface Logger is able to independently turn off the radio in a radio-free environment. Built using our proven Piezo-Resistive sensor and acquisitions electronics, the Surface Logger produces near- quartz quality data in a reliable and economical package. Ambient temperature compensation ensures the long term accuracy of the data, day or night.
Echometer Well sounding devices for determining fluid levels
PDS Memory logging tools - calipers & spinners
Schlumberger Logging services
TecWel TecWel develops and manufactures acoustic logging tools, and provides cased hole logging services.
ThinJack What is ThinJack?
  • ThinJack is a TIG-welded 2mm thick grade 316L steel envelope.
  • ThinJack works by inflating the envelope with hydraulic oil pressure.
  • ThinJack expands by up to 10-15 mm by inflation and exerts hundreds of tonnes of force.
  • ThinJack is the ideal solution to separating and jacking problems in hazardous, difficult to access or restricted areas
ThinJack
Wachs On-site machining, casing and wellhead cutting and valve turning equipment & services.
Weatherford Tubing patches
WellCut Decommissioning Services Engineering services, hot tap machines and field machining services.
Wellube - Unique Marine Group Engineering services, hot tap machines and field machining services.
Sealants
Brinker-Technology At Brinker Technology we offer a unique brand of innovative technical solutions to promote integrity management to the pipeline industry worldwide. Based around our patented Platelet Technology® we deliver these solutions through:
• Implementation of novel leak locating and sealing products and engineering systems
• Expert consultancy
• Ongoing research and development
We are a dynamic and creative company who are focused on implementing our unique technology to the advantage of the pipeline industry worldwide. We are based in Aberdeen, Scotland but have a truly global presence having completed projects in the UK, Norway, Australia, Azerbaijan and Alaska.
CSI Technologies
Subsidiary of Suprior Energy and Wild Well Control
UltraSeal®, an epoxy well sealant designed to create seals over a wide range of well conditions.

CSI Technologies provides research, engineering and oilfield product development for the energy industry.

CSI Technologies solves challenging problems ranging from high-pressure, high-temperature cementing to effective stimulation techniques to lost circulation. The company has a long history of developing new oilfield methods and products using its applied engineering capabilities.
Furmanite Leak-sealing technology and onsite service. Since 1929, we’ve created groundbreaking and patented leak sealing technology; and we consistently provide these solutions with the highest level of service to customers around the world.
Loctite When something breaks, "Repair, don't Replace" it! Replacing household items that break or show wear can become expensive. Any repair - from small to large - can be accomplished with just three Loctite products: Loctite Ultra Gel Super Glue, Loctite 1 Minute Instant Mix Epoxy, or Loctite Power Grab Construction Adhesives. All are Solvent Free making the air nice to breathe, feature easy to use applicators, and are recloseable to allow for multiple uses. For over 55 years, Loctite Adhesives have delivered Trusted Performance and Proven Results. You can tackle any repair with the performance of Loctite.
M & D Industries - "Ultra Seal" Ultra Seal® R Sealant Ultra Seal® R Sealant is a special epoxy resin. The material’s viscosity has been lowered to provide easy mixing and placement. The lowered viscosity is accomplished without the volumetric shrinkage that usually accompanies the thinning of epoxy resin. Applications include micro annular gas migration, mechanical isolation valve, casing leaks, well bore stability, and loss circulation.
Oil Center Research Distributes:
GX Safety Seal (711-714), used to plug leaks in DHSV lines
Hyposeal (527 & 528), used to plug tubing and casing leaks.
Sandaband Sandaband consists of concentrated sand made into a pumpable slurry with water and brines. Sandaband has a particle fraction in excess of 75% by volume. The particle size distribution controls the rheology, permeability and porosity of the slurry. Sandaband characteristics:
  • Behaves as a true Bingham Plastic material
  • It is pumped like a liquid, sets up like a “solid mass” when in place, but without becoming rigid
  • Sandaband is non polluting and chemically inactive.
SealMaker International SEALMAKER International specializes in engineered leak repair solutions. Uses liquid pressure activated sealants to repair troublesome leak problems associated with oil and gas production onshore and offshore.
Seal-Tite Seal-Tite International has a line of pressure activated sealants designed to seal tubing hanger, casing hanger and wellhead leaks; production tubing and casing leaks; microannulus, sustained casing pressure and salt dome storage cavern leaks; control line, safety valve and packer leaks; as well as umbilical, flowline and subsea leaks. After the sealant has reached the leak site, the sealant begins to plate out on the edges of the leak, and simultaneously bridges across the leak to seal it.
Software, Well Examination and Audit Services
Expro - SafeWells www.wellintegrity.com. A software system for managing well integrity related information.
Exprosoft - WIMS Supply "WIMS" - Well Integrity Management System. Software application that will contribute to a uniform and structured approach for handling of well integrity during the lifetime of a well. WIMS will ensure that the information necessary for handling well integrity is available through one system, and with a clear indication of the well barrier status at all times.
Halliburton Halliburton's cementing design software: "Using our programs, operators can complete a range of related tasks, from analyzing the casing and cement sheath, to surveying the surrounding formation to determine the best mechanical properties for an optimum sealant."

Also provides a link to the popular "eRedbook" software.
Intetech - iWIT/a> A software system for managing well integrity related information. Their brochure.
Landmark
OA Tools A free site with web-based calculators. Includes tubing movement, casing burst, DHSV leak rate calculators.
NRG Well Management Ltd

NRG Well Examination and Management Systems Ltd
NRG Well Management Ltd is focused on the cost effective delivery of Project Management for Drilling and Well Operations. In addition we carry out Well Engineering and Field Development Studies which range in size from simple one day technical reviews through to detailed multi disciplinary studies lasting many months, for a wide variety of Clients.

NRG Well Examination & Management Systems Ltd, in addition to providing independent well examination services, specialises in the delivery of workable management systems for upstream Operating Companies and Service Providers. Our Systems assist the client to both manage health, safety and environmental hazards as well as enable them to demonstrate compliance with all the applicable licence and statutory requirements without the need for extensive Management Systems. Apart from satisfying the statutory requirements our Systems contribute towards lowering the cost of operations by ensuring that Clients’ Management focus their attention on their defined responsibilities, whilst enabling them to effectively delegate responsibilities to contractors where necessary.
Peloton - WellView, RigView, SiteView, ProdView Drilling and Well Data Software Solutions
- Peloton is 'well focused' on developing the world's best drilling and well data software solutions.
- Peloton started developing WellView® in 1991 for well operations and schematic visualization. Today, Peloton has evolved to provide a full well lifecycle data management solution for Operations, Drilling and Construction/Reclamations.
- Peloton's comprehensive data model and software technology improves morning reporting, well and site visualization and data quality.
PetEng Calculators A free site with web-based calculators for a large variety of engineering calculations
Well Integrity Tracking System (WITS) A free web site to demonstrate the ability to track the well integrity status of wells.
WellEz WellEz.NET™ for field operations reporting WellEz provides the most convenient and easy-to-use field reporting solution available today. Designed for integrated field reporting for the lifecycle of a well, WellEz.NET leverages web-based technology to manage all well data from initial planning to a variety of reporting functions such as Drilling, Completion, Work-over , Facilities, and Plugging and Abandoning (P&A). In the office, bottom-hole assembly (BHA), drilling mud, well costs and a range of other critical data, can be captured and analyzed using custom Multi-Day and Multi-Well Reports. Wellbore schematics can be automatically created from the field data.
Wellbore Schematic Programs
CSD support@csd.as or +47 91 30 10 06
Enertia Software
WellView Peloton
WellEZ
inter alia
VIPR http://www.parallinx.com/
iHandbood  Schlumberger, www.slb.com
Strater Golden Software. http://www.goldensoftware.com/
Completions Manager Petrofocus www.petrofocus.com
   
Tree-Wellhead Services
Cameron Trees and Wellheads
RS Clare The Clare range of Valve Lubricants for the Oil & Gas Industry has been developed in conjunction with Original Equipment Manufacturers and Production, Drilling and Service operators. Valve Lubricant 601 is a fully synthetic lubricant, ensuring long term lubricating and sealing qualities within a temperature range of -20°F to 450°F. Valve Lubricant 501, an ‘Extended Temperature Range’ valve lubricant has been developed to provide comparable performance to 601 within a temperature range of -75°F to 350°F.
FMC Trees and Wellheads
Vetco-Gray Trees and Wellheads
PTC - Petroleum Technology Company PTC has a variety of speciality tools:
  • Telescopic VR lubricators
  • SealCure for damaged seal bores
 
Regulatory Agencies
Interstate Oil & Gas Compact Commission This links to a very comprehensive list of all states regulations.
AOGCC - Alaska Oil and Gas Conservation Commissions Alaska regulatory agency. Link to the AOGCC report, "Investigation of Explosion and Fire at Prudhoe Bay Well A-22".
MMS - Minerals Management Service U.S. Federal
Railroad Commission of Texas Texas
Alabama Oil and Gas Board Alabama
Louisiana Department of Natural Resources Louisiana
California State Lands Commission, Mineral Resources Management Division California
Alberta, Canada Alberta Energy Board Alberta
 
Other
Yahoo "Well Integrity" Group - http://finance.groups.yahoo.com/group/Well-Integrity/ A Yahoo discussion group with a well integrity theme. Does not get much usage.
Wikipedia article on Well Integrity It's currently pretty sparse, but could be a good place to put best practices.
Southwest Research Institute Southwest Research Institute is an independent, nonprofit applied research and development organization. The staff of 3,000 specializes in the creation and transfer of technology in engineering and the physical sciences. The Institute occupies more than 1,200 acres in San Antonio, Texas, and provides nearly two million square feet of laboratories, test facilities, workshops and offices.
Stress Engineering Services We offer extensive design, testing, and analysis experience in both the upstream and downstream segments of the industry in virtually all phases of operations. Services we provide includes: Riser and Mooring Design & Analysis, Floating Production Systems, Vessel Load / Motion Analysis, Crane Testing and Design Review, Subsea Engineering, Field Instrumentation and Monitoring, Fitness for Service Evaluation, Tubular Testing and Analysis, Component and Tool Design, Full-Scale Component and Systems Testing, Coil Tubing Evaluation for Oilfield Applications, Failure and Finite Element Analysis, Materials Engineering and Metallurgy, Forensic Engineering.
John Wright Company's Technical Library on Blowout Control An outstanding primer on well control operations
Lone Star Steel Casing Reference
Bolting Info
Well Integrity Management System
Proposed Table of Contents
People
Organization, Leadership & Management  
Training for Engineers  
Training for Well Operators  
Plant
Barrier system maintenance Pressure testing wells
B annulus repressurization
Suspension requirements for wells Suspension Guidelines for Inactive Wells
MMS RA of TA Wells
Valve maintenance and lubrication  
Process
Procedures for well operations  
Performance
Metrics and Key Performance Indicators  
Audits
   



Contact: Joe Anders, jlanders@hotmail.com
Revised: 28 June 2010