CAJ | 학술논문

LG地区侏罗系下部地层油气显示活跃,地层压力与显示强度在横向上差异较大并难以准确预测,岩石固有强度普遍低于气体钻井临界强度,井眼不稳定问题较为突出.为解决以上难题,利用测井手段并结合实钻资料分析了LG地区地层压力剖面特征、侏罗系地层气体钻井的井眼稳定性和主要钻井工程地质问题,提出如下技术措施:①合理控制气体钻井的深度,有效规避气体钻井的作业风险,提高气体钻井效率;②在侏罗系下部地层不适合气体钻井的层段,实施欠平衡钻井和PDC钻头复合钻井,来进一步提高超深井钻井速度.
LG지구주라계하부지층유기현시활약,지층압력여현시강도재횡향상차이교대병난이준학예측,암석고유강도보편저우기체찬정림계강도,정안불은정문제교위돌출.위해결이상난제,이용측정수단병결합실찬자료분석료LG지구지층압력부면특정、주라계지층기체찬정적정안은정성화주요찬정공정지질문제,제출여하기술조시:①합리공제기체찬정적심도,유효규피기체찬정적작업풍험,제고기체찬정효솔;②재주라계하부지층불괄합기체찬정적층단,실시흠평형찬정화PDC찬두복합찬정,래진일보제고초심정찬정속도.
There are frequent oil and gas shows in the lower Jurassic formations at the LG area, but the formation pressure and the intensity of oil and gas show vary a lot laterally and are hard to predict in accuracy, and the inherent strength of the rocks is normally lower than the critical strength of gas drilling, so the wellbore unstability is obviously a problem in drilling in this area. For solutions, logs were combined with actual drilling data to study the formation pressure profile of the LG area, the wellhole stability when drilling through the Jurassic formations, and the major geological difficulties for drilling engineering. And following countermeasures are recommended: a. a proper depth for gas drilling can effectively mitigate gas drilling risks, so as to improve the efficiency of gas drilling; b. the UBD and compound drilling with PDC bits can be used for the lower Jurassic formations unfit for gas drilling, it is an important way to improve the ROP of ultra-deep drilling.