摘要
为研究页岩气藏开发过程中页岩基质传输能力动态变化特征,基于Langmuir滑移理论、岩石物性、流体物性及赋存特征,建立了考虑吸附—解吸效应、应力敏感效应、含水饱和度及真实气体效应等多种因素综合影响的页岩基质表观渗透率模型。基于实验和LBM模拟数据验证了建立的表观渗透率模型的可靠性,同时分析了各因素对页岩基质表观渗透率的影响。敏感性因素分析表明:页岩气藏降压开发过程中,基质表观渗透率先降低后升高;除滑脱效应和孔径外,应力敏感效应和储层束缚水是基质表观渗透率的主要影响因素,两者都对页岩基质渗流能力产生不利影响,对表观渗透率的影响都是贯穿整个生产阶段;页岩基质表观渗透率随着渗透率应力敏感系数的增大而减小,随着含水饱和度增加而减小。当含水饱和度达到0.3时,基质表观渗透率在两者共同影响下降低幅度达到87.56%。
Based on Langmuir slip condition,properties of rock and gas,storage mechanisms of fluid,an apparent permeability for gas transport in shale matrix is established.Coupling influence of ad/desorption effect,stress sensitivity effect,water saturation,real gas effect and volume content of organic pores is considered in proposed model,which is used to investigate dynamic change characteristics of gas transport capacity of shale matrix in reservoir condition.Then,the reliability of the proposed model is verified by experimental and LBM simulation data from literatures.During reservoir depletion,the apparent gas permeability of shale matrix initially decreases and then increases.What’more,gas slippage effect,radius,stress sensitivity effect and water saturation have significant impact on apparent gas permeability.The apparent gas permeability of shale matrix decreases with increase of stress sensitivity coefficient and irreducible water saturation.The apparent gas permeability of shale matrix impacted by irreducible water saturation and stress effective effect decreases by 87.56%when water saturation reaches 0.3.The proposed model provides a certain help for evaluating apparent gas permeability of shale matrix in reservoir conditions.
作者
李晓平
刘蜀东
李纪
谭晓华
LI Xiao-ping;LIU Shu-dong;LI Ji;TAN Xiao-hua(State Key Laboratory of Oil-Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;PetroChina Southwest Oil and Gas Field Company,Chengdu 610051,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2021年第6期861-870,共10页
Natural Gas Geoscience
基金
国家自然科学基金项目“页岩气储层双分形孔隙—裂缝网络模型及气水传输机理研究”(编号:51704246)
四川省科技计划项目“页岩气井压裂液返排量预测技术研究”(编号:18SYXHZ0090)联合资助。
关键词
页岩基质
表观渗透率
滑脱效应
应力敏感效应
含水饱和度
Shale matrix
Apparent gas permeability
Gas slippage effect
Stress sensitivity effect
Water saturation
