Hydrocarbon expulsion model and resource potential evaluation of high-maturity marine source rocks in deep basins:Example from the Ediacaran microbial dolomite in the Sichuan Basin,China  

作　　者：Wen-Yang Wang Xiong-Qi Pang Ya-Ping Wang Zhang-Xin Chen Chang-Rong Li Xin-Hua Ma 

机构地区：[1]State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [2]State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China [3]College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China [4]Research Institute of Exploration and Development,Petro China Southwest Oil&Gas Field Company,Chengdu,Sichuan 610041,China [5]Chemical and Petroleum Engineering,Schulich School of Engineering,University of Calgary,Calgary T2N 1N4,Canada [6]School of Earth and Space Sciences,Peking University,Beijing 100871,China [7]Research Institute of Petroleum Exploration and Development(RIPED),Petro China,Beijing 100083,China

出　　处：《Petroleum Science》2022年第6期2618-2630,共13页石油科学（英文版）

基　　金：supported by the Open Fund Project of State Key Laboratory of Lithospheric Evolution [SKL-K202103];support of the Exploration and Development Research Institute of Petro China Southwest Oil & Gas Field

摘　　要：Hydrocarbon expulsion features and resource potential evaluation of source rocks are crucial for the petroleum exploration.High-maturity marine source rocks have not exhibited a hydrocarbon expulsion mode owing to the lack of low-maturity source rocks in deep petroliferous basins.We considered the Ediacaran microbial dolomite in the Sichuan Basin,the largest high-maturity marine gas layer in China,to exhibit a method that quantitatively characterizes the hydrocarbon expulsion of high-maturity marine source rocks.The experiment of fluid inclusion,rock pyrolysis,and vitrinite reflectance(Ro)of 119 microbial dolomite core samples obtained from the Dengying Formation were performed.A hydrocarbon expulsion model of high-maturity source rock was established,and its resource potential was evaluated.The results showed that the Ediacaran microbial dolomite in the Sichuan Basin is a good source rock showing vast resource potential.The hydrocarbon expulsion threshold is determined to be vitrinite reflectance at 0.92%.The hydrocarbon expulsion intensities in the geologic history is high with maximum of 1.6×10^(7)t/km^(2).The Ediacaran microbial dolomite expelled approximately 1.008×10^(12)t of hydrocarbons,and the recoverable resource was 1.5×10^(12)m^(3).The region can be categorized into areasⅠ,Ⅱ,Ⅲ,andⅣ,in decreasing order of hydrocarbon expulsion intensity.Areas with a higher hydrocarbon expulsion intensity have a lower drilling risk and should be prioritized for exploration in the orderⅠ>Ⅱ>Ⅲ>Ⅳ.Two areas,northern and central parts of Ediacaran in the Sichuan Basin,were selected as prospects which had the drilling priority in the future gas exploration.The production data of 55 drilled wells verified the high reliability of this method.This model in this study does not require low-maturity samples and can be used for evaluating high-maturity marine source rocks,which has broad applicability in deep basins worldwide.

关 键 词：Deep petroliferous basin Overmatured source rocks Hydrocarbon expulsion model Resource evaluation Sichuan basin 

分 类 号：P618.13[天文地球—矿床学]