涪陵页岩气田井漏现状与技术对策

Technological Strategies for Lost Circulation of Fuling Shale Gas Field

涪陵页岩气田钻井过程中井漏频繁、类型多样、损失大。在近两年涪陵页岩气田井漏情况统计分析基础上,结合工程地质特征,对漏失机理和防漏治漏的技术难点进行了分析和探讨,针对浅部地层缝、洞型恶性漏失提出了优化井身结构、清水抢钻以及高效堵漏等技术对策;针对中深层依据漏失程度的不同选择随钻堵漏、桥浆堵漏以及膨胀堵漏剂堵漏和水泥浆堵漏技术;针对目的层提出了控压钻井技术以及油基钻井液堵漏体系技术对策。

During the process of drilling in Fuling shale gas field, lost circulation occurred frequently and diversely with a large amount loss of mud. Based on statistic analysis of lost circulation and combined with the characteristics of engineering geology, this paper discusses the mechanism of circulation loss and its technical difficulty. Technological strategies such as optimizing wellbore structure, drilling with fresh water and efficient control of lost circulation are suggested for severe mud losses in shallow fissure and cave; plugging technologies such as plugging while drill- ing, plugging with bridging mud, expansion material or cement, for mud losses in mid--deep formation and technical measures such as pressure--controlled drilling and oil--based drilling fluid system for target zone.