苏里格大气田多成因河道砂体的分布模式研究

以鄂尔多斯盆地苏里格大气田二叠系下石盒子组盒8段河道砂体为研究对象，开展盒8段河道砂体成因类型及分布模式的研究。详细的岩心观察和相标志研究表明，盒8下段为辫状河砂体，盒8上段为曲流河砂体，局部发育网状河砂体。岩性、岩相与砂体的含气性的关系密切，含气砂体与砂岩中的粗岩相单元有良好的对应关系，粗岩相主要发育在高能辫状水道、心滩及曲流河下部边滩内。河道砂体分布模式研究表明，盒8下段发育高能辫状河砂体与低能辫状河砂体模式，盒8上段具有北部网状河、南部曲流河的分布模式。

Model of the distribution of the ploygenetic channel sand body of Sulige large gas field

By researching the channel sandbody in the He-8 Member of Lower Shihezi Formation of Permian System in Sulige large gas field in Ordos Basin,the genetic types and distribution patterns of channel sandbody in He-8 Member has been established.Through analyzing detailed core observation and symbols of sedimentary facies,it was concluded that the sedimentary environment in the area is braid river deposit in the lower section of the He-8 Member,while it is mandering river deposit in the upper section of the He-8 Member.It is anastomosed river deposit in some local area.The lithology and lithofacies of the sandbody are closely related to its gas-bearing property,and the gas-bearing sandbody have good correspondence with the coarse lithofacies units.The coarse lithofacies were mainly developed both in high-energy braid channel and its central bar and the lower part of point bar of the meandering river.According to the study of the channel sandbody distribution pattern,we have found that there are the high-energy braid channels and low-energy braid channels in the lower section of the He-8 Member,and the anastomosed river in the north and mandering river in the south in the upper section of the He-8 Member.