Factors controlling organic-rich shale development in the Liushagang Formation,Weixinan Sag,Beibu Gulf Basin:Implications of structural activity and the depositional environment  

作　　者：Jin-Jun Xu Qiang Jin Xin-De Xu Fu-Qi Cheng Chen-Hui Hu Bin Wang Tao Chen 

机构地区：[1]Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao,Shandong,266580,China [2]CNOOC China Limited,Zhanjiang Branch,Guangdong,524057,China [3]Research Institute of Petroleum Exploration and Development,Shengli Oilfield Company,Sinopec,Dongying,257015,China

出　　处：《Petroleum Science》2021年第4期1011-1020,共10页石油科学（英文版）

基　　金：supported by the Certificate of National Science and Technology Major Project of the Ministry of Science and Technology of China(2016ZX05006-007-004);National Natural Science Foundation of China(41702139,41772138,41602142,42072130);the Fundamental Research Funds for the Central Universities(18CX02008A)。

摘　　要：The mechanisms of lacustrine organic-rich shale formation have attracted attention due to its association with global shale oil and shale gas exploration.Samples of general-quality and excellent-quality source rocks,and oil shale from the Beibu Gulf Basin were analyzed to investigate their organic geochemistry,palynofacies,and trace elements.Hydrocarbon potential was higher in the oil shale(29.79 mg/g)than in the general-quality source rock(3.82 mg/g),and its kerogen type wasⅠ-Ⅱ2.Hydrogen-rich liptinite(cutinite and sporinite)components derived from terrigenous higher plants provided most of the hydrocarbon potential of excellent-quality source rock and oil shale.Under the influence of depressioncontrolling fault activity,a deeper subsidence center promotes the deposition of excellent-quality source rock and oil shale in brackish-hypoxic bottom water.A shallower subsidence center,due to subsag-controlling fault activity,promotes the formation of excellent-quality source rock under freshbrackish and weak oxidation-weak reducing conditions.The local uplift and shallow-slope led to the formation of general-quality source rock,under freshwater weak-oxidation conditions.A model was established for organic matter(OM)accumulation in organic-rich shales,accounting for fault activity,terrigenous hydrogen-rich OM,and the preservation conditions,to predict the development of excellent-quality source rock from areas with low levels of exploration.

关 键 词：Organic-rich shale Geochemical characteristics Palynofacies Structural activity Depositional environment Accumulation model Beibu gulf basin 

分 类 号：P618.13[天文地球—矿床学]