标题：Pore structure evolution of lacustrine shales containing Type I organic matter from the Upper Cretaceous Qingshankou Formation, Songliao Basin, China: A study of artificial samples from hydrous pyrolysis experiments
作者：Han, Hui; Guo, Chen; Zhong, Ning-ning; Pang, Peng; Chen, Shi-jia; Lu, Jun-Gang; Gao, Yuan
作者机构：[Han, Hui; Guo, Chen; Pang, Peng; Chen, Shi-jia; Lu, Jun-Gang] Southwest Petr Univ, State Key Lab Oil & Gas Reservoir Geol & Explorat, Chengdu 610500, 更多
通讯作者：Han, Hui;Zhong, NN;Han, H
通讯作者地址：[Zhong, NN]China Univ Petr, State Key Lab Petr Resource & Prospecting, Beijing 102249, PR, Peoples R China;[Han, H]Southwest Petr Univ, Sch Geosci & T 更多
来源：MARINE AND PETROLEUM GEOLOGY
关键词：Songliao Basin; Lacustrine shale; Type I kerogen; Hydrous pyrolysis;; Extraction; Pore evolution; Shale oil
摘要：To characterize the pore evolution of lacustrine shales containing Type I organic matter, we performed hydrous pyrolysis experiments on a lacustrine shale sample to make it reach various maturities. The samples with various maturities were then extracted using dichloromethane. Total organic carbon content, Rock-Eval pyrolysis, and low-pressure gas (CO2 and N-2) adsorption analyses were performed on the samples before and after extraction. The results showed that the volumes and surface areas of micropores (< 2 nm) of the extracted samples were much higher than those of the artificial samples, but the parameters of mesopores (2-50 nm) of the extracted samples were close to the samples before extraction, indicating that liquid hydrocarbons are mainly stored in micropores. There were no any obvious correlations between pore volumes and mineral contents for the extracted samples, suggesting maturity is the dominant control of pore structure. The pore evolution of the extracted samples is similar to that of the artificial samples. During maturation, micropore volumes initially decreased over the interval 0.71%-0.97% EASY%R-o before increasing at EASY%Ro values exceeding 1.08%. The changes in micropore volume of the extracted samples may be related to the formation and cracking of insoluble organic matter. During this process, mesopore volumes kept increasing, which is mainly aroused by kerogen decomposition or carbon loss. Our results could improve the understanding of pore evolution of lacustrine shales and provide some implications for shale oil storage.