苏里格气田分支井钻(完)井液技术

DRILLING & COMPLETION FLUID TECHNOLOGY IN LATERAL WELL OF SULIGE GAS FIELD

苏里格分支水平井难度最大的地方在于分支井眼,分支井眼首次将大斜度井段和水平段设计为全裸眼,针对苏里格气田分支井眼斜井段和水平段处于同一裸眼段的技术难题,室内研发了强抑制性有机-无机盐低伤害钻井(完井)液体系,并在桃7-14-18H分支井和桃7-15-20H分支井的分支井眼成功试验应用。室内和现场试验结果表明,该体系能有效解决气井水平井斜井段和水平段同处于裸眼段情况下的的泥页岩井壁失稳、气层保护、高摩阻大扭矩、井眼净化、携砂悬砂等一系列技术难题。该体系抑制性强,其页岩一次回收率达到了97.2%,二次回收率达90.3%;体系利于保护产层,对盒7和盒8产层岩心的平均伤害率为10.60%,属于低伤害。钻井液优良的综合性能保障了1742m装有裸眼封隔器的套管完井管串直接穿越裸眼斜井段安全下至水平段的预定位置。

For the deviated section and the horizontal section is in same open hole in the lateral well in Silige gas field,so series of problems need to be solved,such as borehole sloughing,lost circulation,reservoir damage,and so on. An organic- inorganic salt drilling fluid system with low damage and strong inhibitive ability was developed to overcome the problems above. This system has been applied successfully in Tao 7- 14- 18H and Tao 7- 15- 20H lateral wells. Lab. test and field application results showed that the system could maintain hole stability in long time because the first recovery rate of shale cuttings for the fluid was high up 97. 2% and the second recovery rate was 90. 3% which indicated that the fluid had strong inhibitive ability. The average damage rate to pay- zone was 10. 60%which is in favor of payzone protection. 1742m completion string with packers could directly be run in the desired location of the horizontal section through the deviated section because of excellent drilling fluid performance.