Study On Controlling Factors Of Gas And Water Distribution In He 8 And Shan 1 Member In North Sulige

In view of the serious regional water production in the process of natural gas development in Otog Banner area in the north of Sulige,which affects the production of single well and makes it difficult to expand the scale of gas production.Based on the analysis of dynamic and static data,guided by the modern theory of oil and gas accumulation,and with the ancient and modern characteristics as the contrast,this paper makes a geological re-understanding of the regional sedimentary microfacies and reservoir characteristics,and combines the characteristics of gas and water distribution and produced water in the horizontal and vertical directions.The distribution characteristics and laws of gas and water in He 8 and Shan 1 member of the main gas producing strata in the northern Sulige area are revealed in an all-round and multi-angle way,and the accumulation mechanism and controlling factors of tight sandstone gas reservoirs are defined.It is concluded that braided river and delta plain deposits are developed from north to south in the Shan 1 member of North Mountain of Sulige,and braided river and meandering river deposits are developed in the He 8 member of He Formation.Influenced by sedimentation,the sandstone reservoirs of He 8 and Shan 1 member are mainly composed of quartz sandstone,lithic quartz sandstone and lithic sandstone.At the same time,the content of quartz in the reservoir has a certain influence on the reservoir performance.When the content of quartz in the rock is high,the reservoir physical property is better.The distribution characteristics of quartz content in the plane and longitudinal indicate that the provenance direction of the target strata in the study area is northward and northeastward,and the provenance direction of the uplifted strata in the northern basin is closer to the south.The characteristics of gas and water distribution show that the south-north connectivity of the gas reservoir in the west of the transverse study area is better,and the high value area in the east is relatively isolated,showing a sweet spot distribution.The gas reservoir thickness of Shan 1 member is thinner than that of He 8 member,and the distribution range is consistent with sand body deposition.The thickness of the water layer and the gas layer of the first member of the He 8 and Shan 1 Formation is characterized by point strong plane and weak plane.Vertically,the gas layer in the study area is affected by the development of intercalation,and its continuity is relatively poor.In comparison,the gas layer thickness of He 8 member is better than that of Shan 1 member,and the gas layer is widely distributed in strip shape.The longitudinal distribution of water layers in Section 8 and Section1 of the mountain mainly exhibits characteristics of small distribution range,strong local distribution,and isolated distribution.The gas and water distribution pattern is due to the gas intensity of the source rock controlling the gas field distribution in the study area.The influence of the structure on the gas and water distribution is mainly manifested in that the high production gas Wells are mainly distributed in the high point of the structure,while the low production Wells and the producing Wells are mainly distributed in the low point of the structure and the two wings of the structure.Meanwhile,the reservoir conditions and the accumulation driving force are the key to the accumulation of natural gas.The comprehensive analysis shows that the gas intensity,paleostructure,reservoir-forming power and reservoir properties of source rocks in the study area are the main controlling factors of gas and water distribution in He 8 and Shan 1 member,which provides theoretical support for further exploration and development in the area.