高压气井固井界面密封技术研究与应用  

Research and Application of Cement Interface Sealing Technology in High Pressure Gas Wells

作　　者：刘洋[1] 余才焌 张皓月 王德坤 李进 黄盛 LIU Yang;YU Caijun;ZHANG Haoyue;WANG Dekun;LI Jin;HUANG Sheng(Downhole Operation Company of CNPC Chuanqing Drilling Engineering Co.,Ltd.,Chengdu,Sichuan 610051,China;School of Petroleum and Natural Gas Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]中国石油川庆钻探工程有限公司井下作业公司,四川省成都市610051 [2]西南石油大学石油与天然气工程学院

出　　处：《钻采工艺》2025年第2期24-31,共8页Drilling & Production Technology

基　　金：中国石油青年科技专项“川渝高压气井水泥环全生命周期密封失效机理及控制机制研究”(编号:2024DQ03072);中国石油集团公司川庆钻探工程有限公司—西南石油大学工程技术联合研究科技项目“高压气井尾管固井界面密封技术研究”(编号:CQXN-2023-12)。

摘　　要：川中高石梯-磨溪区块四开尾管固井过程中由于上部裸眼地层中的油气活跃,导致固井质量差,降密度后水泥环产生微环隙,固井防窜难度大。其中,2022年有3口井固井后未降密度即气窜,2口井固井后钻井液密度由2.20 g/cm^(3)降至1.30 g/cm^(3)后发生气窜。针对该问题,文章从改善固井质量和预防微环隙两方面入手,形成固井界面密封技术,即研发了密度为1.90~2.30 g/cm^(3)的活性隔离液,一界面冲洗效率达到95.6%,界面混浆也能固化胶结;研制的尾管悬挂器正向密闭装置形成了尾管预应力固井工艺,可承受35 MPa及以上管内压降,改善了微环隙问题;优选了密度2.10~2.40 g/cm^(3)的韧性微膨胀水泥浆,水泥环抗压降能力提高到了40 MPa,满足下开降密度安全钻进。该成果在川中高石梯-磨溪区块?177.8 mm尾管固井中现场应用了5井次,其中固井质量段长合格率均超过70%,下开钻井液密度由2.20 g/cm^(3)左右成功降至1.30 g/cm^(3),未出现喇叭口窜气现象。该研究成果可在高压气井防窜固井中推广应用。Due to the active gas reservoirs in the middle and upper part of Gaoshiti-Moxi block in central Sichuan,it is difficult to prevent gas migration by the four-open liner cementing.In 2022,gas migration occurred in 3 wells without density reduction,and in 2 wells with density reduction(2.20 g/cm^(3)to 1.30 g/cm^(3))of drilling fluid after cementing.Poor cementing quality and micro-annulus generated after density reduction are two main reasons for gas migration.Aiming at this problem,the cementing interface sealing technology is formed from the aspects of improving cementing quality and preventing micro-annulus:An active spacer fluid with a density of 1.90-2.30 g/cm^(3)was developed.The flushing efficiency of the active spacer fluid is 95.6%and the interface mixing slurry can be solidified and cemented.The liner pre-stressed cementing technology and the positive sealing device of liner hanger are formed,which can withstand the pressure drop in the pipe above 35 MPa to improve the micro-annulus problem.The ductile micro-expansion cement slurry system with density of 2.10-2.40 g/cm^(3)was optimized,and the pressure drop resistance of the cement sheath was increased to 40 MPa,which meets the requirements of safe drilling in the next operation.The results have been applied toØ177.8 mm liner cementing for 5 wells in central Sichuan.The qualified rate of cementing quality section length exceeded 70%,and the drilling fluid density decreased from 2.20 g/cm^(3)to 1.30 g/cm^(3),and no gas migration occurred at the wellhead.The research results provide a reference for the gas migration prevention cementing of long sealing section in high pressure gas wells.

关 键 词：高石梯-磨溪区块 尾管固井 气窜 活性隔离液 预应力 韧性微膨胀 界面密封 

分 类 号：TE256[石油与天然气工程—油气井工程]