长庆油田华H50-7井超长水平段钻井液技术

Drilling Fluid Technology for Ultra-Long Horizontal Section of Well Hua H50-7 in the Changqing Oilfield

胡祖彪 张建卿 王清臣 吴付频 韩成福 柳伟荣

HU Zubiao ZHANG Jianqing WANG Qingchen WU Fuping HAN Chengfu LIU Weirong

中国石油集团川庆钻探工程有限公司长庆钻井总公司，陕西西安 710016

Changqing Drilling Corporation, CNPC Chuanqing Drilling Engineering Co. Ltd., Xi’an, Shaanxi, 710016, China

长庆油田陇东地区华H50-7井是一口超长水平段水平井，水平段长达 4 088.00 m，钻遇泥岩层和断层，钻进过程中降摩减阻困难、井眼清洁难度大、泥岩层防塌和断层防漏堵漏难度大。为此，优选了水基钻井液，并提高钻井液的润滑性和抑制性，以降低摩阻和防止泥岩层坍塌；针对不同漏失情况，制定了相应的防漏堵漏技术措施，以解决断层防漏堵漏问题。华H50-7井应用了优选的水基钻井液，采取了制定的防漏堵漏技术，钻井过程中钻井液的润滑性和抑制性稳定，与使用原水基钻井液的邻井相比，下放钻柱和套管时的摩阻降低显著，发生井漏后均成功堵漏，未出现井眼失稳问题。华H50-7井的顺利完钻表明，优选水基钻井液、采取针对性防漏堵漏技术措施，可以解决陇东地区超长水平段水平井钻进中托压严重、易井眼失稳、水平段地层造浆严重和水平段堵漏难度大的问题，这也为将来钻更长水平段水平井积累了经验。

Well Hua H50-7 is a horizontal well with an ultra-long horizontal section in Longdong area of Changqing Oilfield. The ultra-long horizontal section as well as the expected mudstone intervals and faults bring difficulties in resistance reduction, wellbore cleaning, prevention of the mudstone layer from collapsing and fault leakage prevention and plugging. The goal involves optimizing the water-based drilling fluid, the lubricity and inhibition of the water-based drilling fluid are improved to reduce friction and resistance and prevent the mudstone layer from collapsing. Different technical measures for leakage prevention and plugging were developed, depending on the severity of leakage to solve problems of fault leakage prevention and plugging. By applying the optimized water-based drilling fluid and adopting the developed leakage prevention and plugging technology, the drilling of Well Hua H50-7 had been smoothly completed. During the drilling process, the lubricity and inhibition of drilling fluid were stable. Compared with the adjacent wells using the original water-based drilling fluid, the resistance encountered in drilling string and casing running wassignificantly reduced. Lost circulations occurred were successfully plugged without the problem of borehole instability. The successful drilling of Well Hua H50-7 showed that by optimizing the formulation of water-based drilling fluid to improve its lubricity and inhibition, and adopting pertinent leakage prevention and plugging technologies, problems can be solved. Further, the problems involved in drilling the ultra-long horizontal sections of horizontal wells in Longdong Area, such as borehole instability, severe mud-making in the horizontal section, and difficulties in lost circulation control in the horizontal section could be solved effectively. At the same time, the successful completion of this well provided experience for drilling longer ultra-long horizontal section horizontal wells in the future.

https://doi.org/10.11911/syztjs.2020050