摘要
大修侧斜井在上部取套后,泥页岩地层经常出现井壁坍塌问题,造成卡钻、卡井下工具等复杂情况的发生,严重地影响了修井作业的正常进行。为了解决这一技术难题,在对井壁坍塌的物理化学机理进行研究的基础上,室内对聚合物絮凝包被剂、防塌剂和降滤失剂进行了评价和优选,研制出了两种对泥页岩水化具有强抑制性的水基修井液配方,印原浆+0.3％NPAN+0.3％RH-1+0.3％SKCM+0.1％PHAC;原浆+0.3％SPNH+0.3％JN-A+0.1％M101+0.3％SKCM。并提出了相应的实施方案和措施。经在15口大修侧斜井上使用,证实优化设计的修井液滤失量最低,塑性粘度为10～20 mPa·s,动塑比也相对较高(0.36～0.48),并具有一定的防塌效果,井塌发生率由原来的22.5％降至为零。目前这两种修井液正在大庆油田进一步推广应用。
During workover of the slant holes, after the casing is removed out of the upper hole, hole collapse frequently occurs in the shale formation, causing stuck pipe and downhole tools, and impacting the normal workover operation. To solve this technical problem, based on the study on the physical and chemical mechanisms of hole collapse, such additives as polymer flocculating coating agent, sloughing control a-gent and filtrate reducer are evaluated and optimized in the laboratory condition. Two types of water based workover fluids for shale hydration control are developed, i. e. , base fluid+0. 3%NPAN + 0. 3%RH-1 + 0. 3%SKCM+0. 1%PHAC; base fluid + 0. 3%SPNH + 0. 3%JN-A+0. 1%M101 + 0. 3%SKCM. Opera-tion plans and measures are also presented. The optimized workover fluids have been used in 15 slant wells, and they obtained the lowest filtration, their plastic viscosity is 10-20 mPa·s, and their dynamic/ plastic ratio is relatively high (0. 36-0. 48). Sloughing control capacity is remarkable, and the rate of hole collapse drop from 22. 5% to zero. These two types of workover fluids are now using in Daqing oilfield.
出处
《钻井液与完井液》
CAS
北大核心
2002年第5期13-15,共3页
Drilling Fluid & Completion Fluid
