一种适用于低渗储层的钻井液体系

A Drilling Fluid System Suitable for Low Permeability Reservoir

为了降低钻井液在低渗储层开发过程中带来伤害,针对目标储层孔喉和渗透率进行分析,并优化钻井液性能以期满足钻井、储层保护要求。本文对抑制剂、封堵剂以及防水锁剂进行优选,形成一套适合于低渗油气藏开发的高性能水基钻井液。该钻井液具有良好的流变性能和封堵性能,防水锁剂使钻井液滤液的表面张力和油液界面张力显著降低,降低了钻井液对低渗储层造成水锁伤害。低渗岩心污染后,其渗透率恢复值均大于90%,说明该钻井液具有较好的储层保护效果。

In order to reduce the damage caused by the drilling fluid in the development process of low permeability reservoir,the pore throat and permeability of the target reservoir were analyzed,and the performance of the drlling fluid was optimized to meet the requirements of drlling and reservoir protection.In this paper,inhibitor,plugging agent and waterproof locking agent were optimized to form a set of high-performance water-based driling fluid suitable for the development of low permeability oil and gas reservoirs.The drlling fluid had good rheological properties and plugging performance,and the waterproof locking agent can significantly reduce the surface tension and oil interfacial tension of the drilling fluid filtrate,which can reduce the water locking damage caused by drlling fluid to the low permeability reservoir.After low permeability core pollution,its permeability recovery value was greater than 90%,indicating that the drilling fluid had a good reservoir protection effect.