准噶尔盆地南缘天然气成因类型与气源  

Genetic type and source of natural gas in the southern margin of Junggar Basin, NW China

作　　者：陈建平[1,2,3] 王绪龙[4] 倪云燕[1,2,3] 向宝力[4] 廖凤蓉 廖键德[4] 赵长毅[1] CHEN Jianping;WANG Xulong;NI Yunyan;XIANG Baoli;LIAO Fengrong;LIAO Jiande;ZHAO Changyi(Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China;State Key Laboratory of Enhanced Oil Recovery,Beijing 100083,China;Key Laboratory of Petroleum Geochemistry of CNPC,Beijing 100083,China;PetroChina Xinjiang Oilfield Company,Karamay 834000,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]提高石油采收率国家重点实验室,北京100083 [3]中国石油天然气集团公司油气地球化学重点实验室,北京100083 [4]中国石油新疆油田公司,新疆克拉玛依834000

出　　处：《石油勘探与开发》2019年第3期461-473,共13页Petroleum Exploration and Development

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目(06-01A-01-02;2016A-0202)

摘　　要：准噶尔盆地南缘地区很多背斜构造均发现了天然气,但对不同背斜构造天然气的地球化学特征缺乏系统对比研究,特别是最近获得高产的高泉背斜高探1井,天然气类型与来源不清楚。系统梳理和对比该区天然气组分与碳氢同位素组成特征,深入分析天然气成因类型,探讨天然气来源。结果表明,南缘地区天然气以湿气为主,少量干气;南缘中西段天然气碳同位素组成较重而氢同位素组成较轻,东段天然气碳氢同位素组成均较轻;南缘地区天然气属于淡水—微咸水沉积有机质热成因天然气,可以分为煤型气、混合气与油型气3类,且以煤型气和混合气为主。侏罗系煤系为南缘地区主要的天然气源岩,二叠系湖相和上三叠统湖相—湖沼相烃源岩也是重要的天然气源岩。南缘西部天然气来源于侏罗系煤系和二叠系湖相烃源岩,中部天然气主要来源于侏罗系煤系烃源岩,部分来源于二叠系/三叠系烃源岩,东部天然气主要来源于二叠系湖相烃源岩。南缘西部高泉背斜高探1井清水河组油气藏天然气是煤型气和油型气的混合气,侏罗系和二叠系烃源岩的贡献约各占一半。Natural gas has been discovered in many anticlines in the southern margin of the Junggar Basin.However,the geochemical characteristics of natural gas in different anticlines haven’t been compared systematically,particularly,the type and source of natural gas discovered recently in Well Gaotan-1 at the Gaoquan anticline remain unclear.The gas composition characteristics and carbon and hydrogen isotope compositions in different anticlines were compared and sorted systematically to identify genetic types and source of the natural gas.The results show that most of the gas samples are wet gas,and a few are dry gas;the gas samples from the western and middle parts have relatively heavier carbon isotope composition and lighter hydrogen isotope composition,while the gas samples from the eastern part have lighter carbon and hydrogen isotope compositions.The natural gas in the southern margin is thermogenic gas generated by freshwater-brackish water sedimentary organic matter,which can be divided into three types,coal-type gas,mixed-type gas and oil-type gas,in which coal-type gas and mixed-type gas take dominance.The Jurassic coal measure is the main natural gas source rock in the southern margin,and the Permian lacustrine and the Upper Triassic lacustrine-limnetic facies source rocks are also important natural gas source rocks.The natural gas in the western part of the southern margin is derived from the Jurassic coal measure and the Permian lacustrine source rock,while the natural gas in the middle part of the southern margin mainly come from the Jurassic coal measure,partly from the Permian and/or the Upper Triassic source rocks,and the natural gas in the eastern part of the southern margin is originated from the Permian lacustrine source rock.The natural gas in the Qingshuihe oil and gas reservoir of Well Gaotan-1 is a mixture of coal-type gas and oil-type gas,of which the Jurassic and Permian source rocks contribute about half each.

关 键 词：准噶尔盆地南缘 天然气 氢同位素 碳同位素 成因类型 气源判识 侏罗系 煤系地层 

分 类 号：TE122.2[石油与天然气工程—油气勘探]