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Copyright 2002, Offshore Technology Conference This paper was prepared for presentation at the 2002 Offshore Technology Conference held in Houston, Texas U.S.A., 6–9 May 2002. This paper was selected for presentation by the OTC Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Offshore Technology Conference and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Offshore Technology Conference or its officers. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of the Offshore Technology Conference is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of where and by whom the paper was presented. Abstract Initial liner top integrity is a primary concern for most operators. If the liner top fails routine or regulatory integrity tests, expensive and time-consuming remedial operations increase direct costs for equipment and services. This remediation delays well completion, which ultimately delays revenue generation. These expenses often exceed the initial cost of the liner equipment. Liner top failure continues to challenge the industry despite improvements in integrally run liner top packers, special cements, and cementing pratices. Even newer generation liner top packers, run either integrally with the liner hanger or as a second trip packer, have multiple sealing surfaces that must function under rigorous conditions to achieve liner top isolation. The expandable liner hanger has been developed and successfully field-tested as an alternative to conventional “cone and slip” liner hangers and liner top isolation packer systems. The expandable liner hanger combines the functions of the liner hanger and the isolation packer into a single component. The expandable liner hanger uses elastomeric “bands” to provide the axial load capacity of a conventional liner hanger and the annular sealing capability of the liner top isolation packer. The expandable liner hanger is expanded hydraulically with the liner running/setting tool assembly. During expansion, the elastomeric bands are compressed into contact with the ID of the supporting/intermediate casing, virtually eliminating the annular space between the liner hanger and the casing. This paper discusses expandable liner hanger design criteria and testing undertaken to qualify the expandable liner hanger as a reliable liner top isolation system. Initial field installations and the lessons learned are also discussed. Introduction The importance of the liner-casing overlap is illustrated by the efforts and expense taken by operators to ensure hydraulic integrity of the overlap. Typical methods of achieving pressure integrity include the following: • Cement “squeezes,” including a liner top packer as a component of the initial liner hanger setting • One or more “second-trip” liner top isolation packers installed to control gas migration at the liner top The typical liner top is complex in its design (Fig. 1) and can develop leaks due to a myriad of causes1. A recent informal survey of several GOM operators revealed that 30 to 50% of pressure seals in overlaps fail. One operator made a concerted effort to improve liner running and cementing procedures. Data gathered over an 18-month period was used to shed light on possible causes of overlap failure by gathering information on liner/casing sizes, types of equipment, overlap length, mud data, annular cross section, equipment, and service suppliers. The study concluded the chances of having a liner overlap seal failure did not depend on any single factor and the chances for an incident were nearly the same regardless of the factors associated with any given well2. The development and successful deployment of solid expandable tubulars improved the probability of eliminating liner top leaks and reducing the associated remediation costs. The expandable liner hanger is a byproduct of developing expandable openhole and expandable cased-hole liners3. The design features of the anchor joint – elastomeric seals used to seal and anchor the expanded liner to the casing ID – were adapted to run and hang conventional, non-expanded liners (Fig. 2). Expandable Liner Hanger Design Initial design criteria for the expandable liner hanger include the following: • Incorporate solid expandable tubular features into expandable anchor joints to provide maximum axial load capacity and pressure integrity at the liner/casing annulus OTC 14313 Expandable Liner Hangers: Case Histories Melvin J. Moore, BP America Inc.; Donald B. Campo, Shell International Exploration & Production; Joel Hockaday, Enventure Global Technology; Lev Ring, Enventure Global Technology 2 M. MOORE, D. CAMPO, J. HOCKADAY, AND L. RING OTC 14313 • Minimize expandable liner hanger OD for maximum running clearance while maintaining axial load and pressure performance • Provide rotational and reciprocation capability in the liner running/setting tool assembly • Maximize running/setting tool reliability as well as total system reliability • Simplify the running/setting tool cementing pack-off system • Incorporate conventional cementing wiper plug systems and standard float equipment into the expandable liner hanger system System Specifications Initial expandable liner hanger specifications included the following: • Capable of “setting” in 9-5/8 in., 47 to 53.5 lb/ft casing and suspending 7-5/8 in. or smaller liners. • Capable of suspending a minimum of 250,000 lb of liner weight at 250ºF with standard oilfield nitrile elastomer compounds (other compounds are available to increase the temperature range to 400ºF). • Provide a working pressure of 8,000 psi in burst and 4,000 psi in collapse. • Qualify system to ISO/DIS 14310 guidelines for packer systems. System Qualification Initial qualification tests included the following: • Testing potential expandable liner hanger body materials to determine expansion parameters and suitability. This evaluation also included FEA analysis techniques (Fig. 3). • Establishing potential elastomer characteristics when exposed to temperature and common oilfield fluids. • Testing the bond quality of various elastomers when applied to the liner hanger body. • Determining the expansion characteristics of the liner hanger body with elastomeric bands in place. • Qualifying lab-expanded expandable liner hanger sections in fluid and gas environments. • Qualifying mechanical load capacity and pressure integrity when expanded into supporting casing. • Function testing of the liner running/setting tool assembly. • Full-scale testing of the expandable liner hanger system in a deep well simulator. • Field testing the expandable liner hanger system. The qualification test for the expanded liner hanger system entailed expanding a 1-foot section of the expandable liner hanger/liner hanger packer. The 7-5/8 in. base section was expanded into a section of 9-5/8 in. casing that was cemented into a section of 13-3/8 in. casing to simulate actual equipment usage (Fig. 4). This test established an axial load capacity of over 580,000 lb for the single element section and pressure integrity of 11,400 psi was achieved (Fig. 5). Deep well simulator testing was conducted on a full-scale system. The 7-5/8 x 9-5/8 in. expandable liner hanger/liner hanger packer, using five elastomeric bands, was set using the running/setting tool assembly. The 9-5/8 in., 53.5 lb/ft casing was set in the simulator and the expandable liner hanger assembly was placed in position (Fig.6a). The casing and the expandable liner hanger assembly were heated to 300ºF. After temperature stabilized, the expandable liner hanger was “set” (Fig. 6b) and the running/setting tool assembly was retrieved. Testing confirmed the expandable liner hanger assembly met or exceeded the initial design parameters. Subsequent testing established a total “hanging” capacity in excess of 750,000 lb at temperature. After further testing, the expandable liner hanger body was sectioned for evaluation (Fig. 7 and Fig. 8). Case Histories Field Testing Criteria. Following the successful deep well simulator test, the first field test was conducted on a non- producing well in South Texas destined for plugging and abandonment that belonged to Shell Exploration and Production Company (SEPCO). The second field test, also in South Texas, was for a drilling liner for a commercial application on a BP well. The field test sequence was selected for proof of concept: • Run and set the liner under actual conditions • Prove the system’s ability to provide pressure integrity at the liner/casing overlap The operational issues involved were discussed at length and detailed procedures were developed to ensure safety while achieving the goals of successful equipment deployment. Detailed planning consisted of the following: • Outline of the operational overview of running the expandable liner hanger system • Planned sequences • Checkpoints • Contingencies • Results of running the expandable liner hanger system First Field Test. The first field test was conducted at Shell’s Hinojosa No. 8 well, in Fandango Field in Jim Hogg County, Texas. Since there was no risk of lost production and to maximize the value of the test, SEPCO opted to test both the expandable liner hanger system and the expandable sand screen system. As a result of the sand screen testing, liner cementing operations were eliminated. The Hinojosa well was cased with 9-5/8 in., 53.5 lb/ft casing to plug back depth. The bottomhole temperature was approximately 140ºF. To ensure appropriate evaluation of the system functions and procedures, a casing inspection log and a casing scraper run were made before running the expandable liner hanger and expandable sand screen assembly. The casing was filled with 9.5 lb/gal water based mud and tested to 4,000 psi to ensure casing integrity. OTC 14313 EXPANDABLE LINER HANGERS: CASE HISTORIES 3 After initial preparations, the 285-foot expandable sand screen assembly was picked up and run into the hole. The expandable liner hanger assembly, including the liner running/setting tool, was picked up and made up to the spacer joint at the top of the expandable sand screen assembly. The running/setting tool assembly was made up to 4-1/2 in. tubing and run to the setting depth, with the top of the liner at approximately 3,200 ft (Fig. 9). A choke manifold system was incorporated into the pumping system to permit the controlled flow rate (approximately 5 to 8 gal/min) at anticipated expansion pressures of 4,000 psi. Pressure and flow rates were captured during the expansion process. Prior to hanger expansion, appropriate lines were tested to 7,000 psi and an automatic kick-out on the pump truck was set at 6,500 psi and function-tested. After all systems were checked and the appropriate safety meetings were held, the system was slowly brought up to pressure and the expandable liner hanger system was successfully expanded. Expansion pressures were in line with normal parameters. The running/setting tool bypass ports, indicating completion of the expansion process, functioned properly. The running/setting tool was released by slacking off weight to release the collet locking system, and the running tool was released and pulled out of the hole. The expandable sand screen system was expanded using a separate expansion assembly. Following the sand screen expansion, a caliper log was run on a wireline to ascertain the ID of the expanded liner hanger. The expanded ID was approximately 7.58 in., as expected. A test packer was run and set above the liner top to verify pressure integrity. Test pressure at 3,800 psi held for approximately 45 minutes. When all testing was complete, the well was prepared for abandonment per Texas Railroad Commission requirements. Second Field Test. The second field test was actually the first application of the expandable liner hanger technology in a commercial well. This test was conducted on BP’s McLean Heirs No. 7 well in the Northeast Thompsonville Field of Jim Hogg County, Texas. Since this application was a drilling liner, the liner was to be cemented to provide a full-scale operational test of the expandable liner hanger system. The McLean Heirs well was cased with 9-5/8 in., 43.5 lb/ft casing, except the bottom five joints, which were 9-5/8 in., 53.5 lb/ft casing. This configuration permitted using the original size expandable liner hanger equipment without having to run qualification tests for a different weight range system. The 7-5/8 in., 29.7 lb/ft L-80 STL liner was run to a depth of 11,797 ft. The top of the liner was 8,211 ft., for a total of 3,586 ft and a buoyed weight of approximately 80,000 lb (Fig. 10). The bottomhole static temperature (BHST) was 250ºF and the oil-base mud weight was approximately 16 lb/gal. In this case, the expandable liner hanger was run with auto-fill float equipment and a J-type circulating sub above the liner running/setting tool assembly. The liner was run on 5 in. 19.5 lb/ft drill pipe to the setting depth. A choke manifold, as previously run, was planned and used to ensure controlled flow and pressure rates for expanding the liner hanger. The 7-5/8 in., 29.7 lb/ft liner was run according to plan and the expandable liner hanger assembly, including the running/setting tool assembly, was made up to the top joint of casing. The running tool was made up to the first joint of drill pipe, the circulating sub was installed, and the liner was run into the hole following normal liner running procedures. When setting depth was reached, a pump-in sub was made up to the work string, the circulating sub was closed, and the liner was cemented conventionally. After cementing was complete and the liner wiper plug bumped, the circulating sub was opened and the hole was reverse-circulated above the liner top to remove any excess cement. The expansion setting ball was dropped and pumped to the setting tool. High- pressure lines were rigged up to the choke manifold. Data acquisition equipment was rigged up to record expansion pressures and flow rates and lines were tested. After the setting ball reached the ball seat in the setting tool, the system was pressurized to 4,000 psi to initiate expandable liner hanger expansion. Expansion was achieved at the planned pressures and rates. When expansion was complete, the bypass ports in the running/setting tool assembly functioned as designed and the pressure dropped, indicating completion. Weight was slacked off on the setting tool, allowing approximately six inches of travel to release the collet lock system. The running/setting tool was picked up above the liner top, the rams were closed, and the liner top tested to 2,000 psi with 16 lb/gal fluid in the hole. After liner top testing was complete, the running tool assembly was retrieved. Drilling operations resumed. The well was drilled to total depth (TD) and completed. The first application of the expandable liner hanger in a commercial well environment was successful and established that cementing operations could be conducted normally with this new technology (Fig. 11). Lesson learned: Extra choke manifold and flowmeters are not necessary for successfully operating the expandable liner hanger system. Suitable flow rates and control can be provided by pumping systems normally used when cementing liners.The expandable liner hanger running/setting tool assembly did not have a drill pipe pup joint made up onto the top of the tool when picked up. This omission caused some delay, but 4 M. MOORE, D. CAMPO, J. HOCKADAY, AND L. RING OTC 14313 has been corrected by making up the proper pup joint prior to shipping the equipment to location. The spacer tube to connect the liner wiper plug assembly to the expandable liner hanger running/setting tool was too short and required additional time and effort to connect the plug assembly on location. This situation has been rectified. Time spent in planning a liner installation identifies the risks, defines the contingencies, and permits proper operational actions when the equipment is actually run. All parties are aware of potential problems and the actions required for successfully installing the equipment safely and efficiently. Conclusions The expandable liner hanger system provides a viable, technologically advanced method of running and cementing liners. Operational efforts are only moderately different from those used for conventional liner systems. Expansion of the expandable liner hanger/liner hanger packer after cement placement adds minimal risk with proper tools, techniques, and planning prior to running the liner. The expandable liner hanger system improves liner top integrity, significantly reduces the annular area between the liner hanger packer after expansion, and virtually eliminates any gas migration paths. References 1. J. Agnew and R. Kline, “The Leaking Liner Top”, SPE paper 12614, 1984 SPE Deep Drilling and Production Symposium, Amarillo, Texas, April 1-3, 1984. 2. C. Lee Lohoefer and Ben Mathis, Unocal; David Brisco, Halliburton Energy Services; Kevin Waddell, Lev Ring, and Patrick York, Enventure Global Technology; “Expandable Liner Hanger Provides Cost-Effective Alternative Solution”, IADC/SPE paper 59151, 2000 IADC Drilling Conference, New Orleans, Louisiana, February 2000. 3. Filippov, A., et al.: “Expandable Tubular Solutions”, SPE paper 56500 presented at the 1999 SPE Annual Technical Conference and Exhibition, Houston, Texas, October 3-6, 1999. OTC 14313 EXPANDABLE LINER HANGERS: CASE HISTORIES 5 Fig. 1 – Conventional Liner-Top Packers Fig. 2 – Expandable Liner Hanger/Liner Hanger Packer “As Set” Potential Leak Paths 6 M. MOORE, D. CAMPO, J. HOCKADAY, AND L. RING OTC 14313 Fig. 3 – Finite-element analysis used to study stresses during the design of the expandable liner hanger system. Fig. 4 – Test Fixture to Determine Hanging Weight and Seal Effectiveness OTC 14313 EXPANDABLE LINER HANGERS: CASE HISTORIES 7 Fig. 5 – Liner Hanger Tests Fig. 6 – Expandable Liner Hanger Before and After Expansion Figure 6a - Before Expansion Figure 6b - After Expansion 8 M. MOORE, D. CAMPO, J. HOCKADAY, AND L. RING OTC 14313 Fig. 7 – Expandable Liner Hanger Body Sectioned for Evaluation. Fig. 8 – Expandable Liner Hanger Body Sectioned for Evaluation. OTC 14313 EXPANDABLE LINER HANGERS: CASE HISTORIES 9 Fig. 9 – First Installation of an Expandable Liner Hanger System 10 M. MOORE, D. CAMPO, J. HOCKADAY, AND L. RING OTC 14313 Fig. 10 – First Application of Expandable Liner Hanger Technology in a Commercial Well McLean Heirs Jim Hogg #7 Well 17-1/2 in. hole 13-3/8 in. at 2,011 ft 12-1/4 in. hole Top of liner at 8,211 ft 9-5/8 in. at 8,737 ft 8-1/2 in. hole 7-5/8 in., 29.7 lb/ft, P-110, STL Liner for 8,211 - 11,797 ft 6-3/4 in. hole 5th Hinnant Perfs 3-1/2 in. at 13,800 ft 13,800 ft TD OTC 14313 EXPANDABLE LINER HANGERS: CASE HISTORIES 11 Fig. 11 – Expandable Liner Hanger Running Sequence MAIN MENU PREVIOUS MENU -------------------------------------- Search CD-ROM Search Results Print
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