大庆油田Ø100 mm套损井精细压裂工艺技术

Fine fracturing technology for Ø100 mm casing damaged wells in Daqing Oilfield

黄有泉 王金友 张宏岩 程新颖 毛庆波 张春辉

HUANG Youquan WANG Jinyou ZHANG Hongyan CHENG Xinying MAO Qingbo ZHANG Chunhui

中国石油大庆油田有限责任公司 中国石油大庆油田有限责任公司采油工程研究院 黑龙江省油气藏增产增注重点实验室

PetroChina Daqing Oilfield Co., Ltd., Daqing 163453, Heilongjiang, China Oil Production Engineering Research Institute, PetroChina Daqing Oilfield Co., Ltd., Daqing 163453, Heilongjiang, China Key Laboratory of Oil and Gas Reservoir Stimulation of Heilongjiang Province, Daqing 163453, Heilongjiang, China

油田开发过程中出现的套损井，其控制的剩余油需要精细分层压裂挖潜，但是套损井井径局部缩小，常规细分压裂工艺无法实施。研发了Ø95 mm小直径封隔器，优选胶筒胶料增强剂、优化帘线组合，钢体结合盐浴淬火热处理工艺，整体提高封隔器承压与耐疲劳性能；同时研制了小直径导压喷砂器，喷砂口采用斜截面多孔结构设计，减轻了磨蚀；设计了油管防喷阀、重复开关和密封机构。通过室内实验与现场评价试验，套损井精细分层压裂工艺管柱耐温120 ℃、承压70 MPa，单套喷砂器加砂量230 m³，单趟管柱细分压裂11段，可满足Ø100 mm以上井径套损井压裂。在大庆油田累计应用109口井，工艺成功率99.1%，压后单井平均日增油5 t/d以上，对于老油田开发后期套损区块剩余油精细挖潜、注采井网完善起到了积极作用，同时该工艺也可拓展至相同井径的小套管井精细分层压裂。

Fine layered fracturing is required to tap the potential of the remaining oil controlled by wells with casing damage occurred during oilfield development. However, as the wellbore diameter of casing damaged wells is locally reduced, it is impossible to implement the conventional fine layered fracturing process. In this paper, an Ø95 mm small-diameter packer is developed, and in the development of which, the rubber reinforcing agent of the rubber cylinder is carefully selected, the cord combination is optimized, and the steel body is treated with salt bath quenching heat treatment process, as a result, the overall pressure-bearing capacity and fatigue resistance of the packer is effectively improved. In addition, a small-diameter pressure transmitting sandblaster is developed, and the sandblasting port is designed with an inclined cross-sectional and multi-hole structure, which effectively reduces abrasion. A tubing blowout prevention valve is designed, and a repeated switch and sealing mechanism are also innovatively designed in this paper. It has been proved in laboratory and field tests that the fine layered fracturing process string used in the casing damaged wells has achieved the overall temperature resistance of 120 ℃, a pressure-bearing capacity of 70 MPa, the sand adding capacity of a single sandblaster of 230 m. Besides, the fine layered fracturing of 11 intervals can be realized by running the string in a single trip, which can meet the fracturing requirements of casing damaged wells with a restricted diameter of more than 100 mm. This technology has been applied in 109 wells in Daqing Oilfield, with a success rate of 99.1%, and the average daily oil production increase of a single well after fracturing is more than 5 t/d. This fracturing technology plays an important role in the fine tapping of the remaining oil in the casing damaged block and the improvement of the injection-production well pattern in the late stage of the development of the mature oilfield. At the same time, this technology can also be prompted to the fine layered fracturing of small cased wells with the same wellbore diameter.

10.13639/j.odpt.2022.05.017