钻井液与完井液2017，Vol.34Issue(3)：21-26,6.DOI:10.3969/j.issn.1001-5620.2017.03.004
龙马溪页岩井壁失稳机理及高性能水基钻井液技术
Research on Mechanisms of Wellbore Instability of Longmaxi Shale Formation and High Performance Water Base Drilling Fluid Technology
摘要
Abstract
Presently the problem of wellbore instability in long horizontal wells is still a major technical problem in hindering the development of shale gas resources in the world.To solve this problem encountered in the long horizontal well section penetrating the shaly Longmaxi Formation,XRD analysis,pore volume tests by helium adsorption,high pressure mercury test,high resolution field emission SEM,CT scanning and continuous rock engraving strength experiments were used to analyse the micro petro-fabric and physicochemical characteristics of the Longmaxi shale,and their effects on borehole stabilization.The studies showed that the Longmaxi shale was rich in brittle minerals,and the clay minerals were mainly I/S mixed layers.Pores of micro-and nano-meters in sizes were developed,and micro cracks in the formation were slit shaped and in nearly parallel distribution.The presence of water sensitive minerals and the beddings developed therein as well as the micro fractures were the main factors causing shale wellbore instability.A set of wellbore stabilization measures was presented to solve these problems using inhibitive water base drilling fluid with synergistic effect,that is,borehole wall plugging strengthening-controlled inhibitive capacity of drilling fluid-reasonable density of drilling fluid-efficient lubrication of drilling fluid.A high-performance water base drilling fluid was formulated based on this technical strategy,exhibiting good plugging,and the ability to suppress crack propagation.This drilling fluid was used in drilling the 3rd interval of two wells in the Huangjinba block,successfully resolved the problems ofwellbore instability and high friction in the long horizontal section of the Longmaxi shale,providing a new clue and experiences of using water base drilling fluid in the drilling and exploring shale gas resources.关键词
页岩气/井壁失稳/微纳米尺度/孔隙结构/水基钻井液Key words
Shale gas/Wellbore destabilization/Micro/nano size/Pore structure/Water base drilling fluid分类
能源科技引用本文复制引用
唐文泉,高书阳,王成彪,甄剑武,陈晓飞,柴龙..龙马溪页岩井壁失稳机理及高性能水基钻井液技术[J].钻井液与完井液,2017,34(3):21-26,6.基金项目
国家重大专项“彭水地区常压页岩气勘探开发示范工程”(2016ZX05061)、国家自然科学基金重大项目“页岩油气高效开发基础理论研究”(51490650)、“川西低渗气藏低伤害钻井液技术研究”(2016ZX05021004-002)联合资助. （2016ZX05061）
