长裸眼井段承压堵漏工艺技术

Control Mud Losses in Pressured Long Open Holes.

通过评价不同浓度桥塞堵漏钻井液在不同挤注压力下、不同粒径砂粒配制砂床中的堵漏能力,对长裸眼井段承压堵漏工艺进行了研究,介绍了该工艺在T914和P4-2井的应用情况。应用结果表明,采用承压堵漏技术提高长裸眼井段钻井液安全密度窗口成败的重要因素为:对漏失层的准确判定与认识,对承压堵漏钻井液浓度的选择,对挤注压力的选择与控制等;如果不能准确确定漏失层段,需采用全裸眼井段封堵的承压方法,避免因多层漏失造成的漏失层位无法判断而需重复堵漏造成的损失。

Laboratory experiments were conducted on the performance of lost circulation materials (LCMs) in controlling mud losses under different squeeze pressures in long open holes.Field practices in wells T914 and P4-2 were introduced.To stop mud losses in long open holes under pressures,it is most impor- tant to locate accurately the position at which mud losses occurred,the concentration of LCMs used,and the determination of squeeze pressures applied in pumping the LCM mud into the hole.If the position of mud loss can be accurately determined,pump the LCM mud directly to the loss zones;otherwise,squeeze the LCM mud into the whole open hole,avoiding mud losses into multiple loss zones which were difficult to locate.