高石梯构造钻井技术研究与应用

The Research and Application on the Drilling Technology of GaoShi Ladder Construction

高石梯构造位于乐山-龙女寺古隆起区,以震旦系灯影组及上覆寒武系储层为目的层,地层极为复杂,易塌、易漏、石膏层多、地层压力梯度变化大、可钻性差等,钻井速度慢。为了攻克提速问题,分析了本构造的地层特性和难点,优化井身结构设计和钻具组合,优选钻头,采用了螺杆+PDC复合钻井、液动冲击钻井、顶部驱动等工艺技术。本文研究了近几年在高石梯构造上相应工艺技术的运用情况,进行实用性对比分析,总结出了一套高石梯构造的钻井提速技术,通过在高石17井、高石7井等的应用,在防喷防塌防卡和安全提速上效果明显。

Gaoshi ladder construction was located in Leshan - dragon female temple, the ancient GuLong zone, its target stratum was the Sinian Dengying formation and the overlying cambrian reservoir. The stratum was extremely complicated, easily to caving- in and leakiness. In adittion, it had some following features that plenty of gypsum layer, the gradient of the formation pressure changed severely, the drill ability was small and the drilling speed was slow. To overcome the question of speed raise, the formation characteristics and difficulties of this structure were analyzed and made an optimization for the well profile design, drilling assembly and drills. Some good technologies were also utilized, such as Screw ＋ PDC combination drilling, hydraulic percussion drilling and top drive drilling. The application of corresponding technology on Gaoshi ladder structure in recent years was studied, contrastively its practicability was analyzed and a set of technologies for accelerating the drilling speed of the Gaoshi ladder structure were summarized. Through the applications on high stone 17 wells and high stone of 7 well, the effect on spray preventing, caving- in preventing and safely speed accreting was obvious.