鄂尔多斯盆地东部山西组高分辨率层序地层与天然气聚集研究

High-resolution Sequence Stratigraphy and Gas Accumulation of Shanxi Formation in East Ordos Basin

（1.成都理工大学沉积地质研究院，四川成都610059；2.成都理工大学“油气藏地质及开发工程”国家重点实验室,四川成都610059；3.中国建筑西南勘察设计研究院，四川成都610081）

Institute of Sedimentary and Geology, Chengdu University of Technology, Chengdu 610059, China

应用Cross基准面旋回原理，通过对野外露头、钻井岩心和测井等资料的综合分析，对鄂尔多斯盆地东部二叠系山西组进行了高分辨率层序地层研究，提出山西组有两种不同的沉积体系类型，即早期以海陆过渡相的冲积-三角洲-浅海沉积环境为主，平原上的河流类型以辫状河为主；晚期则以陆相的冲积-三角洲-湖泊沉积体系为主，平原上的河流类型以曲流河为主。在层序地层学研究的基础上，探讨了层序地层空间展布及其与天然气聚集的关系，指出山西组中的天然气主要储集于各级旋回层序的上升半旋回中。

Through integrated analysis of field crop, core and logging data, Cross base level cycle principle was adopted to study the highresolution sequence stratigraphy of Shanxi formation in Ordos Basin. Two kinds of different depositional system types were proposed in Shanxi formation. In early phase, sedimentary environment is mainly alluvial-delta-shallow sea of marine-continental transitional facies and braided river of fluvial facies. In later phase, sedimentary environment is mainly alluvial-delta-lacustrine of continental facies and meandering river of fluvial facies. On the basis of researching sequence stratigraphy, the spatial distribution of sequence formations is discussed and its relationship with gas accumulation is probed.The result shows that gas mainly accumulates in rising semi-cycle of various level cycle sequences in Shanxi formation.