页岩油藏流体渗流特征物理模拟新方法  

A new method for physical simulation of flow characteristics of fluids in shale oil reservoirs

作　　者：雷浩 郑有恒[3] 何建华[1] 胡振国[1] Lei Hao;Zheng Youheng;He Jianhua;Hu Zhenguo(Research Institute of Exploration and Development,Sinopec Jianghan Oilfield Company,Hubei Wuhan 430233,China;Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education,China University of Geosciences,Hubei Wuhan 430074,China;Sinopec Jianghan Oilfield Company,Hubei Qianjiang 433124,China)

机构地区：[1]中国石油化工股份有限公司江汉油田分公司勘探开发研究院,湖北武汉430223 [2]中国地质大学构造与油气资源教育部重点实验室,湖北武汉430074 [3]中国石油化工股份有限公司江汉油田分公司,湖北潜江433124

出　　处：《石油学报》2021年第10期1346-1356,共11页Acta Petrolei Sinica

基　　金：国家科技重大专项(2017ZX05049-005);中国石油化工股份有限公司科研项目(P20069-5);构造与油气资源教育部重点实验室开放基金项目(TPR-2019-06)资助。

摘　　要：在页岩油储层岩心CT扫描、聚焦离子束-扫描电镜(FIB-SEM)及压汞资料分析储层微观孔隙结构特征基础之上,运用自主研发的页岩油封闭式高精度渗流评价系统开展了不同物性页岩油岩心渗流物理模拟实验,并借助核磁共振方法(NMR)分析了渗流过程中微观孔隙结构变化特征,明确了页岩油储层中流体渗流规律。研究结果表明:与致密砂岩储层相比,页岩油储层渗流特征复杂,主要表现为3种渗流特征,即"凸型"(岩样气测渗透率K_(g)>2.0 mD)、"线型"(0.1 mD<K_(g)<2.0 mD)及"凹型"(K_(g)<0.1mD),其中只有典型"凹型"及部分"线型"渗流特征可以确定(拟)启动压力梯度;页岩油储层渗流特征主要由边界层和应力敏感的耦合作用所决定,两者的相对强弱决定了页岩油储层渗流会产生不同渗流形态;页岩油储层强应力敏感性会导致渗流特征随着生产压差放大而发生改变,因此页岩油藏数值模拟必须考虑孔隙结构变化对渗流特征的影响。Based on CT scanning of cores in shale oil reservoirs,focused ion beam-scanning electron microscope(FIB-SEM)and analysis of the microscopic pore structure characteristics of the reservoir using mercury intrusion data,the authors conduct physical simulation experiments of flow in cores generating shale oil with various physical properties using the self-developed enclosed high-precision evaluation system of shale oil flow,analyze the changing characteristics of microscopic pore structure during the flow process by means of nuclear magnetic resonance(NMR),and determine the flow laws of fluids in shale oil reservoirs.The research results show that compared with tight sandstone reservoirs,shale oil reservoirs have complex flow characteristics,mainly showing three flow characteristics:convex type(K_(g)>2.0 mD)and linear type(0.1 mD<K_(g)<2.0 mD)and concave type(K_(g)<0.1 mD),of which only typical concave-type and part of linear-type flow characteristics can determine the(pseudo)threshold pressure gradient.The flow characteristics of shale oil reservoirs are mainly determined by the coupling effect of boundary layer and stress sensitivity,and the relative strength of the both determines the different patterns of flow in shale oil reservoirs.The strongly stress sensitivity of shale oil reservoirs will cause the flow characteristics to change with the increasing of the producing pressure drop.Therefore,the numerical simulation of shale reservoirs must consider the influence of changes in pore structure on the flow characteristics.

关 键 词：页岩油 边界层 应力敏感 封闭式高精度渗流评价系统 渗流特征 

分 类 号：TE311[石油与天然气工程—油气田开发工程]