致密储层复杂缝网流固耦合渗流规律及产能模拟  

Fluid⁃solid coupling seepage law and productivity simulation of complex fracture networks in tight reservoirs

作　　者：慎国强[1] 刘浩杰[1] 王振涛[1] 张志明 SHEN Guoqiang;LIU Haojie;WANG Zhentao;ZHANG Zhiming(Geophysical Research Institute of Sinopec Shengli Oilfield Company,Dongying 257022,China;Qingdao Youjin Energy Technology Co Ltd,Qingdao 266400,China)

机构地区：[1]中国石化胜利油田分公司物探研究院,山东东营257022 [2]青岛油金能源科技有限公司,山东青岛266400

出　　处：《大庆石油地质与开发》2023年第4期157-165,共9页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石油化工股份有限公司科技攻关项目“基于黏弹性介质地震流体识别新技术研究”(P21046)。

摘　　要：致密储层在进行压裂改造后,其内分布有众多产状不一、纵横交错的天然裂缝,且与人工裂缝共同构成复杂裂缝网络,导致油气在储层内渗流规律极为复杂,严重制约致密储层油气资源高效开发。鉴于此,基于流固耦合作用的双重介质缝网渗流理论,建立了致密储层复杂缝网渗流体系的理论模型及数值模型,通过COMSOL及MATLAB软件联合仿真技术分析了天然裂缝长度、倾角以及与人工裂缝连通性对储层压力及产能的影响。结果表明:随着天然裂缝长度的增加,储层压力降低范围以压裂水平井为中心逐渐向外扩散,且压力传播范围逐渐增大,累计产油量与裂缝长度呈正相关;裂缝倾角在(0°,75°]时,累计产油量增加幅度较小,但裂缝倾角在(75°,90°]时,累计产油量明显增加,裂缝倾角存在最优值范围;随着缝网之间连通性的增加,储层压力降低程度及范围逐渐增大,且中后期累计产油量大幅增加。研究成果对合理制定致密储层的开发方案及提高产能等具有一定的指导意义。After a tight reservoir is fractured,many crisscrossing natural fractures are distributed in it with different occurrences and form complex fracture networks with hydraulic fractures,causing extremely complex oil and gas seepage law in the reservoir and seriously restricting efficient development of oil and gas resources in tight reser‑voirs.Based on fluid-solid coupling dual-media fracture network seepage theory,theoretical model and numerical model of complex fracture network seepage system in tight reservoirs are established.Influence of length and dip of natural fractures and connectivity of hydraulic fractures on pressure and productivity of reservoir are analyzed by COMSOL and MATLAB softwares co-simulation.The results show that with the increase of natural fracture length,the range of reservoir pressure reduction spreads out gradually from the centre of fracturing horizontal well,with gradual increase of pressure propagation range,and cumulative oil production is positively correlated with fracture length.When fracture dip is(0°,75°],cumulative oil production increase range is small,but when fracture dip is(75°,90°],cumulative oil production increases significantly,and fracture dip has optimal value range.With con‑nectivity increasing in fracture networks,degree and scope of pressure reduction in reservoir get larger gradually,and cumulative oil production increases significantly at middle and late stage.The research provides guiding signifi‑cance for rational development planning and productivity improvement in tight reservoirs.

关 键 词：致密储层 复杂缝网 流固耦合 储层压力 产能模拟 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]