Research On Key Controlling Factors Of Gas And Water Distribution Of Keshen 2 Gas Field In Kuqa Depression

The Kuqa depression which located in the north of Tarim basin,is rich in natural gas.Keshen gas field is another important discovery after Kela 2 gas field which has broad exploration prospects.But due to the particularity of tight sandstone reservoir,the gas-water distribution relationship is complex,not only affect the cost of oilfield production,but also astrict exploration and development policy-makers' thought.Based on the literature search and combining the previous research achievements,this paper analyzes the static geologic data and dynamic production data in the study area,study the gas reservoir fluid characteristics and output,reservoir accumulation period,the types of gas reservoir and finally ascertain gas-water distribution on the plane and vertical,summarize the key controlling factors.It shows that the gas belongs to the dry gas reservior,the type of the formation water is calcium chloride.The water can be divided into two categories of fissure water and connate water which has high salinity.Bashijiqike group of Cretaceous is a set of reservoir with ultra low porosity and permeability.It develops tectonic fracture with stable distribution,good connectivity.The gas accumulates after the densification of gas reservoir.Through the analysis of the structure characteristics of the gas reservoir,it shows that it is a reservoir with edge water,high pressure,faulted anticline.The gas-water distribution of Keshen 2 gas field is complex that the water wells are mainly distributed near fracture,the trap slopes and saddle on plane,the gas and water vent interface is contradiction on vertical,differentiation is not normal.Key controlling factors of gas-water distribution: structure,fracture-cracks and the heterogeneity of reservoir.