Discovery of lacustrine shale deposits in the Yanshan Orogenic Belt,China: Implications for hydrocarbon exploration

作     者：Yuanfu Zhang Xiaodong Yuan Min Wang Pengcheng Ge Yancui Huo Jie Xu Jianguo Zhang Jian Cheng Zaixing Jiang Yuanfu Zhang;Xiaodong Yuan;Min Wang;Pengcheng Ge;Yancui Huo;Jie Xu;Jianguo Zhang;Jian Cheng;Zaixing Jiang

作者机构：School of Energy ResourcesChina University of GeosciencesBeijing 100083China Institute of Earth SciencesChina University of GeosciencesBeijing 100083China PetroChina Research Institute of Petroleum Exploration&DevelopmentBeijing 100083China School of Ocean SciencesChina University of GeosciencesBeijing 100083China Wuxi Branch of SINOPEC Petroleum Exploration&Production Research InstituteWuxiJiangsu 214126China 

出 版 物：《Geoscience Frontiers》 (地学前缘（英文版）)

年 卷 期：2021年第12卷第6期

页      面：326-353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：In the process of writing this paper,we received the financial support of the National Science and Technology Major Project(Grant No.2017ZX05009-002) the support from Wuxi Branch of SINOPEC Petroleum Exploration&Production Research Institute 

主　　题：Luanping Basin Deep-water sedimentation Drill core data Lacustrine deposits Petroleum exploration 

摘      要：The mechanism of formation of lacustrine deposits within stable orogenic belts and their potential for shale oil and gas exploration are frontier themes of challenge in the fields of sedimentology and petroleum exploration. Orogenic belts witness strong tectonic activities and normally cannot host stable lacustrine basins and deep shale formations. Therefore, basins in orogenic belts are considered to have no potential to form shale hydrocarbon reservoirs. Here we investigate the Luanping Basin located in the Yanshan orogenic belt where previous studies regarded rivers and fan deltas as the major main Mesozoic deposits. Based on detailed field exploration and scientific drilling, we report the finding of a large number of lacustrine shale continental deep-water deposits in the Mesozoic strata. Our finding of the occurrence of active shale oil and gas also in this basin also subvert the previous *** report SHRIMP zircon U-Pb age that define the bottom boundary of the target interval as 127.6 ± 1.7 Ma belonging to the early Cretaceous strata. Tectonics and climate are considered to be the main factors that controlled the deep-water sedimentation during this period. The drill cores revealed evidence of shale gas and the TOC of shale is 0.33%–3.60%, with an average value of 1.39% and Ro is 0.84%–1.21%, with an average value of 1.002%. The brittleness index of shale is between 52.7% and 100%. After vertical well fracturing, the daily gas production is more than 1000 m^(3). Our findings show that the basin has considerable potential for shale oil and gas. The geological resources of the shale gas in the Xiguayuan Fm. are estimated as 1110.12 × 10^(8) m^(3), with shale oil geological resources of 3340.152 × 10^(4) t. Our findings indicate that the Yanshan orogenic belt has potential exploration prospect. This work not only redefines the Luanping Basin as a rift deep-water Mesozoic Lake Basin, but also rules out the previous notion that the basin is dominated by