摘要
井壁失稳是制约霍尔果斯背斜钻井速度的重要因素之一。地质、工程资料的综合分析表明:霍尔果斯背斜由于受到构造运动的挤压,地应力高、地层破碎,特别是高陡地层层理发育、地层岩石水敏性强且存在多个压力层系,钻井过程中井下垮塌、漏失等复杂事故频繁发生。研究发现:霍尔果斯井壁失稳多种失稳机理共存、互相作用,以高陡层理性泥页岩地层的井壁失稳为主。因此,合理选择钻井液密度是防止霍尔果斯背斜井壁失稳的关键。研究了霍尔果斯高陡层理性地层井壁失稳的力学机理,建立了合理钻井液密度的确定方法,研究结果在霍003井应用获得良好效果,卡钻等事故大大减少。同时探讨了利用定向井解决井壁稳定问题的可行性,结果表明,可通过避开层理弱面的不利角度降低坍塌压力、扩大安全钻井液密度窗口。
Borehole unstablility is one of the major problems that hamper the drilling speed in the anticline of Huo＇erguosi. Comprehensive analysis of geological and engineering data indicates that, due to the extrusion of tectonic movement, the anticline features high in-situ stresses and fractured formations. High dip formations are rich in stratifications and are strongly water-sensitive, causing frequent borehole collapse and lost circulation problems. Tests and theoretical analysis reveal that the borehole unstability is influenced by many interactive mechanisms with the unstability of high-dip stratification shale dominative. The key to prevent the unstability of high stressed, high-dip stratification shale is proper drilling fluid density. A method for properly determining drilling fluid density is presented, and its application in Well Huo 003 got good results. This paper also discusses the feasibility of using direction drilling to solve the borehole stability problem, which has practical values in dealing with borehole unstability problems.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2007年第1期108-112,共5页
Petroleum Exploration and Development
基金
全国优秀博士学位论文作者专项资金资助项目(200349)
关键词
霍尔果斯
高陡构造
层理性地层
井壁稳定
地应力
钻井速度
Huo＇erguosi
high-dip structure
stratification
borehole stability
in-situ stress
drilling speed
