Successful Application of Expandable Liner Hanger in HT Sidetracking Well Completion: A Case Study in Liaohe Oilfield, China

摘要

There are a number of challenges existing in conventional slip-type liner hanger, such as undersealing annular of overlapping liner, limited high temperature resistant performance, et al. With the development and improvement of expandable tubular technology, expandable liner hanger (ELH) is developed to replace the current hanger and external packer completely, aiming at the shortcomings of the conventional liner hanger. ELH can isolate packer liner and the main casing, replace the conventional cement sealing way, and reduce the overlap length. Here a new thermostable ELH was developed to apply in HT sidetracking well completion. The length of annular seal section of ELH is short but reliable, and maximum sealing pressure reaches 35 MPa. According to the requirements of the drilling process, tool string can be lifted, lowered, rotated and circulated to ensure extension liner string down to the bottom and improve the quality of liner cementing. The construction process is simple with low pressure, reliable operation and long service life after the production. The ELH has large bore size, larger than conventional casing under the hanger, in order to run in oil pump through the extension liner string. So the running in depth of pump is not affected by hanger diameter that can improve oil recovery ratio. The metal sealing is used in ELH for heavy oil thermal recovery wells, and it can be used under highest temperature of 300 C. This ELH tool string can fulfill tool setting and bottom sub salvage at one trip. The annular seal pressure of ELH is more than 35 MPa, construction pressure is 25 to 35 MPa, and suspension force is 600 kN. This new ELH technology has been applied in HT sidetracking well completion in Liaohe oilfield. The hanger position is from 1491 m to 1493 m, inclination is 89 degree, the length of overlapping section in casing is 33 m, the length of sieve tube is 204 m, the length of blank casing is 55 m, and total length is 259 m. The running in depth of sieve tube guide shoe is 1753 m. Lift string suspending weight is 32 tons. ELH suspension was successful. This paper provides a solution to HT sidetracking well completion using thermostable ELH technology. And the experience of operation process was shared in this case to be helpful for technology applications in similar situations.