ANALYSIS OF RELATIVE SEALING AND ABSOLUTE PERMEABILITY OF FAULT-TAKING PERMIAN HYDROCARBON CHARACTERISTICS OF THE REGION 8 AND THE BAIKOUQUAN AREA, NORTHWEST MARGIN, THE JUNGGAR BASIN FOR EXAMPLE

In this paper,according to the characteristic analysis of oil and gas of the Xiazijie and Fengcheng Formation in fault oil field of the region 8 and the Baikouquan area of the Northwest margin,the Junggar Basin,the authors discussed the fault's property of sealing and unsealing.Ordinarily,for the fault oil and gas accumulation,there is an intimate relation between the horizontal distribution features of hydrocarbon characteristics and the sealing property of the fault.In a strong sealing fault hydrocarbon reservoir,because of the gravitational force differentiation of oil and gas,the contents of dissolved gas in the crude oil and methane will gradually increase and the density and the viscosity of crude oil will decrease from the bottom to the top of reservoir.While in a poor sealing fault hydrocarbon reservoir,the righter hydrocarbons are easily lost near the fault.From the bottom to the top of the fault reservoir,the contents of dissolved gas in crude oil and methane will gradually decrease and the density and the viscosity of crude oil will increase.When different hydrocarbon reservoirs have same pool formation conditions,the characteristics of oil and gas will have a regularity alteration owing to the different sealing property.In the research area,there is different degree sealing to updip faults of the hydrocarbon reservoir.They have all absolute unsealing and relative sealing.For the hydrocarbon reservoir of the Xaizijie and Fengcheng Formation,there is a relatively better sealing in the region 8 than in the Baikouquan area.