济阳页岩油渗流机理及开发规律研究  

Research on flow mechanism and development law of Jiyang shale oil

作　　者：张世明 孙红霞[1] 刘祖鹏[1] 刘艳[1] 路广 陈李杨 陈建勋 朱玉瑞 刘巍[1] 张典栋 ZHANG Shiming;SUN Hongxia;LIU Zupeng;LIU Yan;LU Guang;CHEN Liyang;CHEN Jianxun;ZHU Yurui;LIU Wei;ZHANG Diandong(Exploration and Development Research Institute,Shengli Oilfield Company,SINOPEC,Dongying City,Shandong Province,257015,China)

机构地区：[1]中国石化胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《油气地质与采收率》2024年第5期38-47,共10页Petroleum Geology and Recovery Efficiency

基　　金：中国石化重点科技攻关项目“页岩油效益开发优化关键技术研究”(P24026)。

摘　　要：济阳页岩油资源潜力巨大,但受复杂地质条件影响,对压裂后多尺度空间渗流机理及开发规律缺乏系统认识,规模效益开发难度大。为厘清济阳页岩油开发规律的内在机制,针对济阳页岩油多尺度裂缝发育特征,综合物理实验与数值模拟等多种手段,研究压裂后复合缝网的形成机制及组合模式,开展多尺度裂缝应力敏感、多级孔缝内流体非线性渗流、孔缝系统渗吸置换等多重介质空间渗流机理研究。依据压裂改造后多尺度缝网的分布及其渗流规律的差异性,建立了页岩油“易流-缓流-滞流”三区渗流模式,明确了济阳页岩油不同流动阶段的渗流特征与开发规律。研究结果表明:层理缝发育可改善储层物性条件,提高渗吸置换效率,降低启动压力梯度;弹性开发阶段随地层压力下降,渗流通道减小,缝网导流能力降低,具有明显的应力敏感性。济阳页岩油开发过程中,开发初期流态以易流区供液的裂缝线性流和裂缝椭圆流为主;开发中期缓流区向易流区供能,流态转变为地层椭圆流;开发后期滞流区内的页岩油逐渐动用,流态转变为边界控制流。受地质条件和生产制度影响,不同水平井能量变化、含水率下降和产量变化规律具有较大差异。合理优化闷井时间和生产制度,能够保证渗吸置换效果,高效利用地层能量,提高页岩油产能。Jiyang shale oil resources have enormous potential.However,there is a lack of systematic understanding of seepage mechanism and development laws in the multi-scale spaces after fracturing due to the influence of complex geological conditions,making it difficult to achieve large-scale beneficial development.In order to clarify the formation mechanism of the development law of Jiyang shale oil,the multi-scale fracture characteristics of Jiyang shale oil were analyzed.The formation mechanism and combination mode of fracture networks after fracturing were studied using physical experiments and numerical simulations.In addi-tion,seepage mechanisms in multi-medium spaces were researched,including the stress sensitivity of multi-scale fractures,nonlin-ear flow in multi-scale pores and fractures,and imbibition displacement of pore-fracture systems.According to the differences in the distribution of multi-scale fracture networks and their flow laws after fracturing,a three-zone flow pattern of“easy flow-slow flow-difficult flow”for shale oil was established.Finally,the flow characteristics and production laws of Jiyang shale oil at different flow stages were clarified.The research results indicated that the developed bedding fractures could improve the physical properties of reservoirs,enhance imbibition displacement efficiency,and reduce start-up pressure gradient.During the elastic development stage,the flow channels reduce,and the fracture network conductivity decreases as the formation pressure declines,resulting in sig-nificant stress sensitivity.In the development process of Jiyang shale oil,the initial flow state is mainly dominated by linear flow and elliptical flow of fractures supplied by the easy flow zone.In the middle stage of development,the slow flow zone supplies en-ergy to the easy flow zone,and the flow state changes to elliptical flow in the formation.Moreover,the shale oil in the difficult flow zone is gradually produced,and the flow state changes to boundary-controlled flow in the later stage of d

关 键 词：页岩油 渗流机理 多尺度孔缝 应力敏感 开发规律 

分 类 号：TE311[石油与天然气工程—油气田开发工程]