摘要
川南地区是我国最早开发页岩气的地区,肩负着推动我国页岩气发展的重要任务。但是川南地区页岩气藏钻井过程中井壁垮塌严重,影响了该地区页岩气藏的勘探开发进程。基于现场取芯室内实验,从微观结构、矿物组分及流体对岩石物性的影响,对该地区页岩进行研究。分析了硬脆性页岩稳定性。得出该地层井壁失稳机理主要是在井筒压差以及毛管力作用下钻井液滤液沿层理面渗入,导致层理面的力学性质发生变化,从而引起页岩整体强度下降出现剥落,最终造成井壁失稳垮塌。通过对该区块页岩实验研究分析,为该地区页岩钻井过程中钻井液优选提供有效的理论支撑,确保页岩层段钻进高效、顺利地进行。
South of Sichuan area is the earliest region of shale gas development and shoulder promoting the im-portant task of shale gas development in our country. But wellbore collapse seriously during drilling in shale forma-tion, it has greatly influenced exploration of shale gas in this region. Based on experiment of formation shale core, microstructure of shale, mineral constituent and the influence of drilling fluid to shale property are researched. It analyzes the stability of hard and brittle Shale from experiment angle. It thinks that this formation instability mecha- nism is mainly due to drilling fluid infiltrate stratification of stratified shale in pressure of well and capillary force. It changes the mechanics properties of stratification and leads to the strength of stratification down and wellbore col-lapse. The experiment study of shale provides theory support for optimization of drilling fluid and ensure drill in the shale formation safely and smoothly.
出处
《科学技术与工程》
北大核心
2012年第30期8012-8015,共4页
Science Technology and Engineering
基金
国家科技重大专项课题(2011ZX05022-005)资助
关键词
川南地区
页岩气
层理
井壁失稳
South of Sichuan Basis,shale gas, stratification, wellbore instability
