鄂尔多斯盆地中央古隆起东侧奥陶系中组合天然气成因与来源  

Genesis and source of the Ordovician mid-assemblage natural gas in the east side of the central paleo-uplift,Ordos Basin

作　　者：李军 赵靖舟[1,2] 王大兴[3] 孙六一[3] 任军峰[3] 武春英[3] 吴伟涛[1,2] 赵子龙[1,2] 曲付涛 

机构地区：[1]西安石油大学地球科学与工程学院,陕西西安710065 [2]陕西省油气成藏地质学重点实验室,陕西西安710065 [3]中国石油长庆油田公司勘探开发研究院,陕西西安710018

出　　处：《石油学报》2016年第7期821-831,共11页Acta Petrolei Sinica

基　　金：国家自然科学基金项目(No.41502132);国家重大科技专项(2011ZX05007-004)资助

摘　　要：随着鄂尔多斯盆地奥陶系天然气勘探工作的不断深入,中央古隆起东侧奥陶系马家沟组五段5亚段—马家沟组五段10亚段中组合天然气勘探取得了重要进展,但目前有关天然气成因与来源的研究还很薄弱。根据天然气地球化学特征、古油藏发育特征等分析结果,并结合天然气成藏地质背景,厘定了鄂尔多斯盆地中央古隆起东侧奥陶系中组合天然气的成因与来源。研究表明,鄂尔多斯盆地奥陶系中组合天然气为上古生界煤系烃源岩生成的煤型气与下古生界碳酸盐岩烃源岩生成的油型气的混合气,并以上古生界煤型气为主。现今气藏天然气组分中甲烷主要来自上古生界煤系烃源岩,上组合以及中组合少部分天然气的乙烷较多来自下古生界油型气,中组合大部分天然气乙烷及重烃仍来自上古生界煤系烃源岩。With the continuous deepening of Ordovician natural gas exploration in Ordos Basin, a great advancement has been achieved in the mid-assemblage natural gas exploration of Sub-member 5 to Sub-member 10 of Member 5, Ordovician Majiagou Formation in the east side of the central paleo-uplift. However, there is still insufficient research on the genesis and source of natural gas. Based on the geochemical characteristics of natural gas, the development characteristics of paleo-oil reservoirs and other analysis results, in combination with geological conditions of natural gas accumulation, the genesis and source of Ordovician mid-assemblage natural gas in the east side of the central paleo-uplift, Ordos Basin are determined. The research indicates that Ordovician mid-assemblage natural gas in Ordos Basin is a mixture of the coal type gas derived from Upper Paleozoic coaly source rocks and the oil associated gas generated from Lower Paleozoic carbonate rocks, dominated by Upper Paleozoic coal type gas. Among the current natural gas corn positions of gas reservoirs, the methane is mainly sourced from the Upper Paleozoic coaly source rocks, the ethane in a small part of upper assemblage and mid assemblage natural gas is mostly derived from the Lower Paleozoic oil associated gas, while the ethane and heavy hydrocarbon of most mid assemblage natural gas are originated from the Upper Paleozoic coaly source rocks

关 键 词：天然气碳同位素 煤型气 气源对比 奥陶系中组合 鄂尔多斯盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]