Geochemistry and origin of deep-seated cracked gas on the northern slope of the Dongying Sag, Shandong Province

作     者：CHANG Xiangchun HAN Zuozhen XU Youde SHANG Xiaofei YAN Chengpeng 

作者机构：Shandong provincial Key Laboratory of Deporattonal Mmeraltzatlon and Sedtmentary Mmerals Shandong Umverslty of Science and Technology Qingdao 266510 China Geological Scientific Research Instttute of Shengli Oilfield Company SINOPEC Dongying 257001 China 

出 版 物：《Chinese Journal Of Geochemistry》 (中国地球化学学报)

年 卷 期：2011年第30卷第3期

页      面：353-358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：supported by the Primitive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province (Grant No.BS2010HZ016) the University Research Program of Shandong Province (Grant No. J09LE08) the Open Fund of Key Laboratory of Depositional Mineralization and Sedimentary Minerals, Shandong Province (Grant No. DMSM200807) 

主　　题：干酪根裂解气 东营凹陷北部 地球化学特征 山东省 碳同位素组成 起源 干酪根类型 分子组成 

摘      要：Deep-seated cracked gas exploration was achieved great breakthrough in Es4L of the Minfeng area on the northern slope of the Dongying Sag. Carbon isotopic and molecular compositions studies revealed the characteristics of wet gas and a normal trend of carbon isotopic composition. Empirical cutoff points of δ13C2 and δ13C3 and light hydrocarbon compositions distinguished the cracking gas as sapropelic gas. Variations in i/nC5, i/nC4 and δ13C2 fur-ther confirmed that the gas was cracked from residual kerogen. Source characteristics indicated that the gas was de-rived from mature-highly mature source rocks of Es4 with kerogen type II being dominant mixed with some oil-cracking gas. Burial history modeling indicated that there were two hydrocarbon charging periods in Es4L reser-voirs. The first period refers to the Guantao-Minghuazhen stage dominated by oil charging, while the second period refers to the Minghuazhen stage and has been dominated by cracked gas charging till now.