缝洞型油藏水驱剩余油形成机制及换向注水增油机理  

Mechanisms of remaining oil formation by water flooding and enhanced oil recovery by reversing water injection in fractured-vuggy reservoirs

作　　者：王敬 齐向生[1,2] 刘慧卿 杨敏[3] 李小波[3] 刘洪光[3] 张拓峥[1,2] WANG Jing;QI Xiangsheng;LIU Huiqing;YANG Min;LI Xiaobo;LIU Hongguang;ZHANG Tuozheng(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;MOE Key Laboratory of Petroleum Engineering,China University of Petroleum,Beijing 102249,China;Research Institute of Exploration and Development,Northwest Oilfield Company,Sinopec,Urumqi 830011,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)教育部重点实验室,北京102249 [3]中国石化西北油田分公司勘探开发研究院,乌鲁木齐830011

出　　处：《石油勘探与开发》2022年第5期965-976,共12页Petroleum Exploration and Development

基　　金：国家自然科学基金企业创新发展联合基金“深层碳酸盐岩油藏流动机理与开发方法”(U19B6003-02-06)。

摘　　要：为了更加清晰地认识缝洞型油藏水驱剩余油形成机制、分布规律和水驱后换向注水时剩余油动用机理,基于缝洞要素、配置关系、典型缝洞结构,利用CT扫描技术和3D打印技术制作了不同特征缝洞结构三维可视化物理模型,开展了水驱油和换向注水模拟实验。研究表明,缝洞型油藏水驱剩余油形成机制包括注采井控不足、油水重力差异、流道间干扰、弱连通通道封隔、远端弱水动力等5种,在这些机制作用下可能形成注采井网不完善型、盲端型、顶部阁楼型、重力驱绕流型、次流道绕流型、弱通道封隔型、远端弱连通型等7类水驱剩余油。水驱后换向注水可以动用部分剩余油,但采出程度提高幅度与剩余油类型、缝洞结构和换向注采结构有关,其中5类剩余油大致对应重力置换、开辟新流道、抬升溢出点位置、增强水动力、垂向均衡驱替、水动力与重力协同效应等6种换向注水增油机理。To get a deeper understanding on the formation mechanisms and distribution laws of remaining oil during water flooding, and enhanced oil recovery(EOR) mechanisms by reversing water injection after water flooding, 3D visualization models of fractured-vuggy reservoir were constructed based on the elements and configuration of fractures and vugs, and typical fracture-vug structures by using advanced CT scanning and 3D printing technologies. Then, water flooding and reversing water injection experiments were conducted.The formation mechanisms of remaining oil during water flooding include inadequate injection-production well control, gravity difference between oil and water, interference between different flow channels, isolation by low connectivity channel, weak hydrodynamic force at the far end. Under the above effects, 7 kinds of remaining oil may come about, imperfect well-control oil, blind side oil, attic oil at the reservoir top, by-pass residual oil under gravity, by-pass residual oil in secondary channel, isolated oil in low connectivity channel, and remaining oil at far and weakly connected end. Some remaining oil can be recovered by reversing water injection after water flooding, but its EOR is related to the remaining oil type, fracture-cavity structure and reversing injection-production structure. Five of the above seven kinds of remaining oil can be produced by six EOR mechanisms of reversing water injection: gravity displacement, opening new flow channel, rising the outflow point, hydrodynamic force enhancement, vertically equilibrium displacement,and synergistic effect of hydrodynamic force and gravity.

关 键 词：缝洞型油藏 水驱 剩余油 换向注水 增油机理 提高采收率 3D打印 

分 类 号：TE344[石油与天然气工程—油气田开发工程]