摘要
涠洲西部油田涠二段易垮塌地层所用常规油基钻井液油水比和破乳电压低,乳化状态稳定性不够,易引起地层泥页岩水化分散,给井壁失稳和储层保护造成困难。在分析涠二段硬脆性灰色泥岩垮塌机理基础上,通过改善乳化剂的乳化稳定性、优化复合粒径封堵材料,构建了改良后强封堵钻井液体系。室内性能评价结果表明,优化后的改良后油基钻井液乳化稳定性强,塑性黏度小、滤失量小、封堵效果好,抗污染能力强。该体系已在WZ12-2-B34井中成功应用,解决了长裸眼涠二段易垮塌地层井壁失稳问题。
In Weii Section of Weizhou West Oilfield,the conventional oil-base drilling fluid used in the strata prone to collapse had low oil-water ratio and demulsification,and the emulsification state was not stable enough,which easily caused the formation shale hydration and dispersion,causing difficulties to borehole wall instability and reservoir protection.On the basis of analyzing the collapse mechanism of hard brittle gray mudstone in Weizhou Ii section,the improved strong plugging drilling fluid system was established by improving the emulsifying stability of emulsifier and optimizing the compound particle size plugging material.The indoor performance evaluation results show that the optimized modified oil-base drilling fluid has strong emulsification stability,low plastic viscosity,small filtration loss,good plugging effect and strong anti-pollution ability.The system has been successfully applied in WZ12-2-B34 well and solved the problem of borehole wall instability in weizhou Ii section with long open hole.
作者
刘思宁
尹瑞光
黄丹
王博
冼田德
Liu Sining;Yin Ruiguang;Huangdan;Wang Bo;Xian Tiande(Cosl Zhanjiang Operating Company,GuangDong Zhanjiang 524057)
出处
《石化技术》
CAS
2020年第12期115-116,共2页
Petrochemical Industry Technology
关键词
油基钻井液
井壁失稳
应用
Oil based drilling fluid
Borehole instability
