页岩气层水-岩作用机理、特征及意义  

Mechanism,characteristic,and significance of water-rock interaction in shale gas reservoirs

作　　者：程秋洋 杨洪志[3] 游利军[2] 康毅力[2] 常程 谢维扬 贾钠 唐雪峰 CHENG Qiuyang;YANG Hongzhi;YOU Lijun;KANG Yili;CHANG Cheng;XIE Weiyang;JIA Na;TANG Xuefeng(Shale Gas Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu City,Sichuan Province,610056,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,City,Sichuan Province,610500,China;PetroChina Southwest Oil and Gas Field Company,Chengdu,City,Sichuan Province,610051,China;Program of Petroleum Systems Engineering,Faculty of Engineering and Applied Science in University of Regina,Regina,SKS4S0A2,Canada)

机构地区：[1]中国石油西南油气田公司页岩气研究院,四川成都610056 [2]油气藏地质及开发工程全国重点实验室西南石油大学,四川成都610500 [3]中国石油西南油气田公司,四川成都610051 [4]工程与应用科学学院里贾纳大学,加拿大SKS4S0A2

出　　处：《油气地质与采收率》2024年第6期96-108,共13页Petroleum Geology and Recovery Efficiency

基　　金：中国石油天然气集团公司科技专项“页岩气规模增储上产与勘探开发技术研究”(2023ZZ21);非常规油气层保护四川省青年科技创新研究团队项目“页岩气层氧化协同水力压裂减量增渗方法研究”(2021JDTD0017);中国石油西南油气田公司博士后科研项目“页岩自支撑裂缝气-水流动机理及生产制度优化研究”(20230304-13)。

摘　　要：页岩气效益开发依赖水平井分段水力压裂技术,然而水基钻井液、碱性油基钻井液、滑溜水压裂液、前置酸液和氧化性破胶液与页岩发生水-岩作用,潜在影响着钻井过程井壁稳定、压裂改造效果、压后闷井及返排效果。通过系统综述国内外页岩气层水-岩作用机理、水-岩作用下页岩组构响应特征,讨论了水-岩作用对页岩气开发的意义。综述认为,页岩富含水敏性组分黏土矿物等、酸敏性组分碳酸盐矿物、碱敏性组分石英等和氧敏性组分有机质和黄铁矿;页岩矿物组分水解程度极低,但黏土矿物水化膨胀、促缝现象突出;页岩孔隙和裂缝的分布均与化学不稳定组分石英、碳酸盐矿物、有机质和黏土矿物密切相关,化学溶蚀包括酸化溶蚀、碱液侵蚀和氧化溶蚀;水-岩作用下页岩组分溶蚀,诱发孔缝溶扩并劣化岩石力学性质。研究指出,推动工作液配方优化,攻关应用氧化性酸液和氧化性压裂液,有利于提高压裂造缝效果和促进吸附气产出,提高气层采收率;基于闷井压降曲线拐点确定最长闷井时间,构建考虑缝网导流能力保护的控压生产制度,有利于指导气井生产全过程合理控压,延长稳产期,提高单井产量。Horizontal well multi-stage hydraulic fracturing technology makes the development of shale gas reservoirs efficient.However,water-rock interaction between shale rock and the work fluids like water-base drilling fluid,alkaline oil-base drilling fluid,slick-water fracturing fluid,pre-acid fluid,and oxidizing rubber breaking fluid may potentially affect wellbore stability,fracturing stimulation effect,shut-in performance,and flowback efficiency during the drilling process.This paper discusses the significance of water-rock interaction on shale gas development by systematically summarizing the mechanism of water-rock interaction and the response characteristics of shale pore structure under water-rock interaction in shale gas reservoirs in China and abroad.Shale is found rich in water-sensitive components such as clay minerals,acid-sensitive components such as carbonate minerals,alkali-sensitive components such as quartz,and oxidative-sensitive components such as organic matter and pyrite.The hydrolysis of shale components is very poor,while hydration swells and associated fracture generation due to clay minerals are prominent.The distribution of pores and fractures in shale is closely related to the chemically unstable components of quartz,carbonate minerals,organic matter,and clay minerals.Chemical dissolutions include acidizing,alkali,and oxidative dissolutions.The dissolution of shale components under water-rock action induces the dissolution and enlargement of pores and fractures,which also impairs the mechanical properties of rock.It is pointed out that optimizing working fluid,like the application of oxidative-acid and oxidative fracturing fluid,is conducive to improving the fracturing stimulation effect,promoting adsorption gas production,and improving shale gas recovery.Meanwhile,determining the maximum shut-in time based on the inflection point of the pressure drop curve and constructing the pressure control production system considering the protection of the diversion capacity of the fracture network can g

关 键 词：页岩气层 水力压裂 工作液 水-岩作用 氧化 闷井 控压生产 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]