关键词: 苏里格气田, 辫状河, 沉积模式, 沉积相, 储层结构

Abstract: The eighth member of Shihezi Formation(He8) and the first member of Shanxi Formation(Shan1) of the Permian in Sulige Gas Field of Ordos Basin show obvious petrological,sedimentological and geologic climatic characteristics as follows.The clastic grain size is large,and the mineralogy and fabric maturity are low.The common cross-strata and massive structures showing strong water dynamic conditions are developed,and the vertical grain successions varies greatly.There are commonly lateral superposition of sandstones and exposure signs.There was seasonally dry geologic climate during the deposition period.These characteristics indicate the intervals deposited from the braided rivers.Based on the above characteristics,a new braided river model for the reservoirs of Sulige Gas Field was established.Compared with the traditional braided river models,the new model emphasizes that abandoned channels,crevasse splays and flooding plains were developed during the deposition periods of He8 and Shan1 Member and resulted in the frequent interlayers in the reservoir.The sizes of effective sandbody indicated by unstable well test and the constitution of effective sandbody show that the framework sandbody in the reservoirs of Sulige Gas Field has good continuity,and the effective sandbody is distributed in the framework sandbody in the shape of lens.

Key words: Sulige Gas Field, braided river, sedimentary model, sedimentary facies, reservoir structure