CAJ | 학술논문

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6618 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。
룡강61정시사천분지룡강서지구제1구비상규초심정，완찬정심6618 m。주라계지층정벽은정성차，종향상압력계통복잡，심부해상지층H2S 함량초과30 g/m3、동시존재이상초고압CO2 기층화염수층，정저압력초과110 MPa、온도재150 ℃이상。위차，룡강61 정채취료여하찬정기술조시：채용6 개제비상규투관층서봉격불동복잡층단，유효예방화공제정하지질풍험；재봉래진—사계묘조역루지층응용공기찬정방루치루、방사쾌타；대자류정조화수가하조강연마성지층우화찬두설계，병재소정안단진행PDC 찬두제속시험；우화항고온취광수기찬정액，사지구비교강적항고온、항염급항개오염능력。실천표명，룡강61 정비상규초심정찬정기술불부유효해결료복잡지층소대래적찬정난제，실현안전쾌속찬지목적층，이차환재천투지구초심정찬정기술상득도창신，형성료일투교완정적비상규초심정찬정기술。
Well Longgang-61 is the first unconventional ultradeep well in West Longgang Region in Sichuan Basin with a total depth of 6 618 m. The Jurassic wellbore wall is poor in stability; the vertical pressure system is complex; the H2S content in deep marine formation is over 30 g/m3; there also exists CO2 zone and brine zone with abnormally high pressure; the bottom hole pressure is over 110 MPa and the temperature is over 150 ℃. For this reason, Well Longgang-61 adopted the following drilling techniques: using 6-spud system and unconventional casing program to isolate various complex intervals, effectively preventing and controlling downhole geologic risks; using air drilling in leakage-prone formations in Penglai Town-Shaxi Temple Formation to prevent fluid loss and prevent deviation and ensure fast drilling; for formations with strong abrasivity in Ziliujing Formation and Xujiahe Formation, the drilling bit desing was optimized and accelerating test was performed for PDC drilling bit in slim hole section; and optimizing high temperature poly-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 difficulty caused by formation complexity and realized safe and fast drilling to the target zone, but it was innovated in drilling of ultra-deep wells in Sichuan and Qiongchong areas, creating a set of complete drilling technologies for ultra-deep wells.