Research and practice of completion string treatment technology with permanent packer in“Three Super” gas well
Author of the article:MA Qun, ZHANG Hongqiang, XU Penghai, ZHENG Rusen, ZHANG Liang, YIN Hongwei, LIU Hanguang
Author's Workplace：CNPC Tarim Oilfield Branch Company, Korla, Xinjiang, 841000, China
Key Words：“Three Super” gas well; String failure; Overhaul operation; Permanent packer; Complex treatment; RCT cutting
Abstract：In
Keshen gas field, the reservoir is extremely deep (≥6000 m), the formation pressure is extremely high (≥120 MPa)and the formation temperature is extremely
high (≥165℃).
The gas well was completed with a downhole safety valve THT permanent packer
string. In view of the problems of production string breakage, deformation and
corrosion leakage in“Three
Super”gas wells, which seriously affect the normal production of gas wells, the
downhole string treatment technology is studied. A complete set of technology
including well killing, RCT(Radial Cutting Torch) cutting, permanent packer
treatment, fishing and corresponding tool selection has been developed. Since
2015, more than 20 accident wells have been successfully repaired, and good
results have been achieved, which provides reference for the ultradeep
high temperature and high pressure gas wells.