川东北陆相页岩储层井壁失稳机理研究  

Study on Wellbore Instability Mechanism of Continental Shale Reservoir in Northeastern Sichuan Basin

作　　者：高书阳 薄克浩 张亚云 高宏 皇甫景龙 GAO Shuyang;BO Kehao;ZHANG Yayun;GAO Hong;HUANGFU Jinglong(Sinopec Research Institute of Petroleum Engineering Technology Co.,Ltd.,Beijing 10226;Shale Oil and Gas Enrichment Mechanism and Effective Development State Key Laboratory,Beijing 10226;Petroleum Engineering Technology Research Institute of Zhongyuan Oilfield,Sinopec,Puyang,Henan 457000)

机构地区：[1]中石化石油工程技术研究院有限公司,北京102206 [2]页岩油气富集机理与有效开发国家重点实验室,北京102206 [3]中国石化中原油田分公司石油工程技术研究院,河南濮阳457000

出　　处：《钻井液与完井液》2025年第2期217-224,共8页Drilling Fluid & Completion Fluid

基　　金：国家自然基金项目“高精度地震导向钻井关键技术及软件”(U23B6010);中石化科技部重点攻关项目“多类型气藏钻完井关键技术”(P24231)。

摘　　要：为解决川东北陆相千佛崖页岩储层垮塌严重、成井难度大的技术难题,系统性地开展了失稳特征分析和室内实验评价研究。现场资料分析表明,失稳主要发生在千一段灰黑色页岩层段,具有失稳周期无规律,坍塌与漏失共存的特征,现用钻井液体系无法有效维持易塌地层的稳定性。室内研究发现,千一段不同层段间井壁稳定性差异较大,其中易塌层段灰黑色页岩层段黏土矿物含量高,具有一定的水化膨胀性能和双亲性润湿特征;其层理性强,有机质擦痕滑动镜面等(弱结构面)极为发育,胶结强度较弱,导致地层天然破碎,岩石力学性能大大降低;在钻井液及工程扰动作用下,沿弱结构面剥落掉块,引发井壁失稳坍塌。该研究提出了规避易塌层段等安全成井技术对策,为后期陆相页岩油气水平井施工提供参考和借鉴。Shale reservoirs in the Qianfoya continental facies shale reservoirs in northeastern Sichuan collapsed seriously,leading to severe difficulties in drilling a well successfully.To deal with this problem,a systematic analysis of instability characteristics and laboratory experimental evaluation studies were carried out.The analyses of the field data show that the instability mainly occurs in the dark-gray shale layer of the Qianyi member of the Qianfoya Formation,which is characterized by an irregular instability cycle and a coexistence of collapse and lost circulation.Drilling fluids currently used cannot effectively maintain the stability of this easyto-collapse formation.Laboratory studies have shown that there are significant differences in the wellbore stability among different layers of the Qianyi member of the Qianfoya Formation.Among them,the dark-gray shale layer in the formation has a high content of clay minerals and certain degree of hydration swelling and amphiphilic wetting characteristics.The Qianyi member has strong bedding and the organic matter scratch sliding mirror surface et al.(weak structural surfaces)in the shales are extremely developed.The cementation strength of the shales is weak,resulting in natural breaking of the formation and significant reduction in the rock mechanical properties.Under the action of the drilling fluid and drill string disturbances,the shales peel off and cave in,causing wellbore instability and collapse.This study has presented technical countermeasures for safe and successful drilling,such as avoiding the formations that are prone to collapse,providing references for horizontal well drilling for continental shale oil and gas in the future.

关 键 词：川东北 陆相页岩 千佛崖 井壁失稳 技术对策 

分 类 号：TE254[石油与天然气工程—油气井工程]