油气地质与采收率2024，Vol.31Issue(6)：96-108,13.DOI:10.13673/j.pgre.202308031
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
摘要
Abstract
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,frac-turing stimulation effect,shut-in performance,and flowback efficiency during the drilling process.This paper discusses the signifi-cance 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 guide the reasonable pressure control in the whole process of gas well production,extend the stable production period,and increase the production of a single well.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Key words
shale gas reservoirs/hydraulic fracturing/working fluids/water-rock interaction/oxidation/shut-in/pressure control production分类
能源科技引用本文复制引用
程秋洋,杨洪志,游利军,康毅力,常程,谢维扬,贾钠,唐雪峰..页岩气层水-岩作用机理、特征及意义[J].油气地质与采收率,2024,31(6):96-108,13.基金项目
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). （2023ZZ21）
