Organic matter occurrence and pore-forming mechanisms in lacustrine shales in China

作     者：Li-Chun Kuang Lian-Hua Hou Song-Tao Wu Jing-Wei Cui Hua Tian Li-Jun Zhang Zhong-Ying Zhao Xia Luo Xiao-Hua Jiang Li-Chun Kuang;Lian-Hua Hou;Song-Tao Wu;Jing-Wei Cui;Hua Tian;Li-Jun Zhang;Zhong-Ying Zhao;Xia Luo;Xiao-Hua Jiang

作者机构：Science and Technology R&D DepartmentCNPCBeijing100000China Research Institute of Petroleum Exploration and DevelopmentCNPCBeijing100083China National Energy Tight Oil and Gas R&D CenterBeijing100083China Key Laboratory of Oil and Gas ReservoirsCNPCBeijing100083China 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2022年第19卷第4期

页      面：1460-1472页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：sponsored by the National Natural Science Foundation of China(42072187,42090025) CNPC Key Project of Science and Technology(2021DQ0405) 

主　　题：Shale oil Unconventional oil and gas Organic matter Pore evolution Log interpretation model 

摘      要：The evolution of pore structure in shales is affected by both the thermal evolution of organic matter(OM)and by inorganic diagenesis,resulting in a wide variety of pore *** paper examines the OM distribution in lacustrine shales and its influence on pore structure,and describes the process of porosity *** principal findings are:(i)Three distribution patterns of OM in lacustrine shales are distinguished;laminated continuous distribution,clumped distribution,and stellate scattered *** differences in total organic carbon(TOC)content,free hydrocarbon content(S_(1)),and OM porosity among these distribution patterns are discussed.(ii)Porosity is negatively correlated with TOC and plagioclase content and positively correlated with quartz,dolomite,and clay mineral content.(iii)Pore evolution in lacustrine shales is characterized by a sequence of decreasing-increasing-decreasing porosity,followed by continuously increasing porosity until a relatively stable condition is reached.(iv)A new model for evaluating porosity in lacustrine shales is *** this model,the organic and inorganic porosity of shales in the Permian Lucaogou Formation are calculated to be 2.5%-5%and 1%-6.3%,respectively,which correlate closely with measured *** findings may provide a scientific basis and technical support for the sweet spotting in lacustrine shales in China.