抗高温强抑制性钻井液体系的研究与应用

摘要

Troublesome of borehole stability is often encountered in JABUNG oilfield of Indonesia, which is caused by strong water sensitive Gumai shale. The KC1-GWTEMP drilling fluid system is developed with additives of GWTEMP, asphalt sealing agent GWTEX and filtrate reducer GSL (black lignite emulsion), in which the GWTEMP is a novel high temperature (over 205℃.) polymer encapsulating and inhibiting agent. The laboratory and application results show that the drilling fluid system has good performances of rheology, filtration, sealing and inhibiting, the extreme pressure lubricating factor is lessthan 0.05, which the borehole diameter enlargement rate is only 3.14%.%印尼JABUNG油田的Gumai泥页岩地层水敏性极强,因井壁失稳造成的井眼事故频繁发生.通过选用新型抗高温聚合物包被抑制剂GWTEMP、沥青类抗高温降滤失封堵剂GWTEX,并引入油基钻井液用降滤失封堵剂GSL(黑色液态褐煤乳液)等高效处理剂,构建了满足JABUNG油田钻井需要的KCl-GWTEMP强抑制性钻井液体系,其中GWTEMP抗温在205℃以上,抗盐达饱和,分子量较其他聚合物包被剂分子量低,易溶于水.室内实验和现场试验均证明,该钻井液具有良好的流变性、降滤失性、封堵和抑制性能,能保持井壁稳定;极压润滑系数在0.05以下,可很大程度地减少高扭矩和压差卡钻等的发生;试验井井眼规则,电测井径扩大率仅为3.14％.