顺北油气田超深井分段完井技术

Staged Completion Technology for Ultra-Deep Wells in Shunbei Oil and Gas Field

顺北油气田储层发育多条断裂,每个断裂内有一条或多条栅状储集体,储集体间分隔性强,需要通过分段改造动用多个断面储集体,提高油气井产能。为此,通过优化橡胶材料的配方、硫化工艺和完井工具的机械结构,研发了耐高温高压的大扩张比裸眼封隔器、投球分级滑套、压差滑套、完井封隔器等分段完井用关键工具。基于两性离子酸用稠化剂和有机–无机抗高温双重交联剂,研制了抗高温交联缓速酸;利用压裂液和酸液的黏度及密度差异,形成了远距离沟通深部酸压工艺。在研发关键完井工具、高温酸液、酸压工艺的基础上,基于地质工程一体化理念,研究形成了顺北油气田超深井分段改造完井技术。顺北油气田12口井应用了该技术,应用结果表明:裸眼封隔器、投球分级滑套和压差滑套耐温180℃、耐压90 MPa,分段级数可达5级;交联缓速酸耐温180℃,黏度提高2倍以上,酸岩反应速率降低20%以上,酸液穿透距离由100 m提高至120 m;现场应用分段级数最高达到4级,封隔器下深达8833 m,应用温度最高达182℃;压后折算产量同比邻井平均提高20%,SHB4-5H井等3口井达到日产油量超过千吨,实现了少井高产。

The reservoirs in Shunbei Oil and Gas Field have developed multiple fractures,each with one or more grating-like reserves.Such highly separated reserves require the stimulation of multiple fractured reserves through staged completion to enhance well productivity.By optimizing the formulation of rubber materials,vulcanization technology,and mechanical structure of completion tools,key tools for staged completion such as high-temperature and high-pressure resistant open hole packers with large expansion ratios,ball-throwing grading sliding sleeves,differential pressure sliding sleeves,and completion packers were developed.A high-temperature resistant crosslinking retarded acid was developed based on the developed amphoteric acid thickening agents and organic-inorganic high-temperature resistant double crosslinking agents.By using the differences in viscosity and density of fracturing fluids and acid liquids,a deep acid fracturing technology for remote connection was formed.Based on the research and development of key completion tools,high-temperature acid liquids,and acid fracturing processes,a staged completion technology for ultra-deep wells in the Shunbei Oil and Gas Field was formed following the concept of geology and engineering integration,which had been applied in 12 wells in Shunbei Oil and Gas Field.The results show that the open hole packers,ball-throwing grading sliding sleeves,and differential pressure sliding sleeves can withstand the temperature of 180℃and pressure of 90 MPa,with stage levels up to 5.The crosslinking retarded acid system can withstand the temperature of 180℃,with viscosity increased by more than two times and acid rock reaction rate reduced by more than 20%.The penetration distance of acid liquids was increased from 100 m to 120 m.The maximum stage level applied on site has reached 4,with packers down to 8833 m in depth with highest temperature of 182℃.After fracturing,the production rate was increased by 20%compared to adjacent wells on average.Three wells including SHB4-5H reached a daily production of 1000 tons,and the goal of high production within few wells was achieved.