柴达木盆地东部石炭系石油地质条件及油气勘探前景

PETROLEUM GEOLOGIC CONDITIONS AND EXPLORATION PROSPECTS OF CARBONIFEROUS IN THE EAST OF QAIDAM BASIN

张建良 钟建华 李亚辉 段宏亮 李雪静 尹成明

Zhang Jianliang Zhong Jianhua Li Yahui Duan Hongliang Li Xuejing Ying Chengming

中国科学院, 广州地球化学研究所, 广州, 510640 2. 中国科学院, 研究生院, 北京, 100871 3. 中国石油化工股份有限公司, 江苏油田分公司, 地质科学研究院, 江苏, 扬州, 225009 4. 中国石油大学, 资源与信息学院, 山东, 东营, 257061 5. 中国石油化工股份有限公司, 江苏油田分公司, 地质科学研究院, 江苏, 扬州, 225009 6. 中国石油与天然气股份有限公司, 青海油田分公司, 石油勘探开发研究院, 甘肃, 敦煌, 736202

Guangzhou Institute of Geochemistry, Chinese A cademy o f Sciences,Guangz hou, Guangdong 510640, China 2. Graduate School,Chinese A cademy of Sciences, Beijing 100871, China 3. Research Institute of Geologic Sciences, Jiangsu Oil Field, SINOPEC, Yangzhou, Jiangsu 225009, China School of Geo-resources and Information, China University of Petroleum, Dongying, Shandong 257061, China 5. Research Institute of Geophysical Prospecting Technology, Jiangsu Oil Field, SINOEC, Nanjing, Jiangsu 210046, China 6. Research Institute of PetroleumExploration and Develop ment, Qing hai Oil Field,Petro China, Dunhuang, Gansu 736202, China

在大量烃源岩有机地球化学分析的基础上,结合区域地质调查及地震解释资料,分析柴达木盆地东部石炭系的石油地质条件及油气勘探前景。该区石炭系分布广、残留厚度大,烃源岩类型丰富。其中,暗色泥岩有机碳含量平均为1.85%(风化校正后),有机质类型以Ⅱ2型和Ⅲ型为主;碳酸盐岩有机碳含量平均为0.42%(风化校正后),有机质类型以Ⅱ型为主;分别达到好烃源岩和中等烃源岩的标准。除宗务隆山前及都兰地区有机质热演化程度较高外,其他地区烃源岩成熟度中等(Ro值平均为1.17%),有机质正处于成熟阶段的生、排烃高峰期,具有较强的生烃能力。该区发育多套储、盖层及多种类型油气圈闭,发生过油气生成、运移和聚集成藏的过程,具有较好的石油地质条件和良好的油气勘探前景。德令哈坳陷石炭系烃源岩条件好,残留厚度大,为有利生油区。宗务隆山前逆冲带和托南断阶带为有利勘探区。

Based on organic geochemistry analysis of source rocks,combined with regional geologic survey and seismic data interpretation,it is discussed in this paper geologic conditions and exploration prospects of Carboniferous in the east of Qaidam Basin.Carboniferous is widely distributed in the region with large residual thickness.There are many categories of hydrocarbon source rocks.Dark-colored mudstones belong to good source rocks with 1.85% of organic carbon,type-Ⅱ2 and Ⅲ organic matters and moderate maturity.And carbonates belong to moderate source rocks with 0.42% of organic carbon,type-Ⅱ organic matters and moderate maturity.All source rocks are in the peak period of oil generation and expulsion and have strong hydrocarbon generation ability,except for those in the Zongwulong mountain front belt and the Dulan area,where thermal evolution degree is too high.With moderate-good source rocks,several reservoir beds and capping formations as well as good trap conditions,Carboniferous in the east of Qaidam Basin has experienced the process of hydrocarbon generation,migration and accumulation,hence is favorable for petroleum exploration.The Delingha Depression is most favorable for hydrocarbon generation with good Carboniferous source rocks and large residual thickness.The Zongwulong mountain front structural belt and the Tuonan fault terrace belt are prospective areas.

国家自然科学基金项目(40503003);教育部高等学校博士点基金项目(20030425008)

https://doi.org/10.11781/sysydz200802144