摘要
龙岗61井是四川盆地龙岗西地区第1口非常规超深井,完钻井深6 618 m。侏罗系地层井壁稳定性差,纵向上压力系统复杂,深部海相地层H2S含量超过30 g/m3、同时存在异常超高压CO2气层和盐水层,井底压力超过110 MPa、温度在150℃以上。为此,龙岗61井采取了如下钻井技术措施:采用6开制非常规套管层序封隔不同复杂层段,有效预防和控制井下地质风险;在蓬莱镇—沙溪庙组易漏地层应用空气钻井防漏治漏、防斜快打;对自流井组和须家河组强研磨性地层优化钻头设计,并在小井眼段进行PDC钻头提速试验;优化抗高温聚磺水基钻井液,使之具备较强的抗高温、抗盐及抗钙污染能力。实践表明,龙岗61井非常规超深井钻井技术不仅有效解决了复杂地层所带来的钻井难题,实现安全快速钻至目的层,而且还在川渝地区超深井钻井技术上得到创新,形成了一套较完整的非常规超深井钻井技术。
Well Longgang-61 is the first unconventional ultradeep well in West Longgang Region in Sichuan Basin with a totaldepth of 6 618 m. The Jurassic wellbore wall is poor in stability; the vertical pressure system is complex; the H2S content in deepmarine formation is over 30 g/m3; there also exists CO2 zone and brine zone with abnormally high pressure; the bottom hole pressure isover 110 MPa and the temperature is over 150 ℃. For this reason, Well Longgang-61 adopted the following drilling techniques： using6-spud system and unconventional casing program to isolate various complex intervals, effectively preventing and controlling downholegeologic risks; using air drilling in leakage-prone formations in Penglai Town-Shaxi Temple Formation to prevent fluid loss and preventdeviation and ensure fast drilling; for formations with strong abrasivity in Ziliujing Formation and Xujiahe Formation, the drilling bitdesing was optimized and accelerating test was performed for PDC drilling bit in slim hole section; and optimizing high temperaturepoly-suphonated water-based drilling fluid so as to provide it with strong capability in resistance to high temperature, salt and calcium.Practice shows that the drilling technology for unconventional ultra-deep well Longgang-61 not only addressed the drilling difficultycaused by formation complexity and realized safe and fast drilling to the target zone, but it was innovated in drilling of ultra-deep wellsin Sichuan and Qiongchong areas, creating a set of complete drilling technologies for ultra-deep wells.
出处
《石油钻采工艺》
CAS
CSCD
北大核心
2015年第2期19-23,共5页
Oil Drilling & Production Technology
基金
国家自然科学基金"基于流-固-化耦合理论的欠平衡钻水平井井壁失稳机理研究"(编号:51474186)
中国石油川西北气矿科技项目"剑阁区块高温高压超深井钻井技术研究"(编号:XNS05JS2013-158)
关键词
四川盆地
龙岗地区
超深井
非常规井
小井眼
抗高温水基钻井液
Sichuan Basin
Longgang Region
ultra-deep well
unconventional well
slim hole
heat resistance water-based drilling fluid
