鄂尔多斯盆地晚古生代三角洲沉积体系平面展布特征

THE DELTA DEPOSITIONAL SYSTEM DISTRIBUTION OF LATE PALEOZOIC ERA IN ORDOS BASIN

利用钻井资料对鄂尔多斯盆地晚古生代三角洲沉积体系进行详细研究 ,结果表明 :研究区晚古生代沉积可以划分为两个阶段 ,第一阶段为晚石炭世本溪期 -早二叠世太原期 ,系海相三角洲沉积体系发育时期 ;第二阶段为早二叠世山西期 -晚二叠世石千峰期 ,系湖泊三角洲沉积体系广泛发育时期。两类不同的三角洲沉积体系在发育的背景、相带构成、砂体类型等方面均有差异。在上述基础上系统讨论了研究区晚古生代三角洲沉积体系平面展布特征 ,为该区下一步的油气勘探提供更为准确的基础资料。

It has been proved by oil and gas exploration that most oil and gas resources occur in the sandbodies of the delta depositional system in Ordos basin. Therefore, it is very important to study the feature of plane distribution of the delta depositional system in Neopaleozoic. According to a quantity of drive well materials, this paper makes a deep study of the late Paleozoic delta depositional system in Ordos basin. The result indicates that it can be divided into two stages. The first stage is the late Carbonic Benxi period early Dias Taiyuan period, and it is delta depositional system of marine facies. The second stage is the early Permian Shanxi period late Permian Shiqianfeng period, and it is delta depositional system of lake facies. There are differences in the development background, composition of facies zone, type of sandbodies between these two kinds of the delta depositional systems. On the basis of the above, the paper discusses the feature of plane distribution of the delta depositional system. It is very useful for future oil and gas exploration.