Research On Preservation Condition Of Oil And Gas In Middle-shallow Layer Of Binbei Region

Through analyzing the devlopment characteristics and the seal ability of caprock of K1qn and K1n1+2 in Binbei region, this paper evaluated the seal ability of caprock of K1qn and K1n1+2 in Binbei region by means of comprehensive evaluation of fuzzy mathematics. The result indicates that from the north to the south, from the east to the west, the seal ability of four caprocks is better and better, the good seal areas of caprock distributes in Heiyupao sag and its south.Based on the research of the seal mechanism of the faults, this paper researched the vertical seal of T1 and T2 fautlts in Binbei region by means of the mudstone content in fault zone and the pressure of fault plane .The result indicates the good seal areas of T2 fault for gas and oil distribute in Daqing-Anda and their north of Binbei region, the good seal areas of T| fault for gas and oil distribute in Wuyuer and Heiyupao sags of Binbei region. By means of the theory of gas diffusion,we divided two gas diffusion systems: K1qn~K1n1+2 and K1n1+2~the earth surface in Binbei region.Based on the research,this paper estimated the diffusion losing amount of the sourcerock of K1qn and K1n1+2 in Binbei region in the different geologic period by corrected Pick's law, the result indicates the diffusion losing amount of the sourcerock of K1qn is 5.3 1011m3 and the diffusion losing amount of the sourcerock of K1n1-2 is 2.5 1011m3,they are 34%and 19.4%of their tolal generation gas amount. It indicates that the diffusion is the important factor of gas losing in Binbei region.This paper researched the hydrodynamic pressure and its change characteristics in the space by means of the ion concentration of formation water, reduced pressure and its change characteristics in the plane,The result indicates that from north-east to south-west,the hydrodynamic conditions are better and better in Binbei region, the areas near the Binbei railroad are the favorable area for oil and gas to accumulate. Based on the research on the controlling of caprock condition ,fault and hydrodynamic conditions to oil-gas distribution, this paper prospected the favorable areas of middle-shallow layer for oil and gas in Binbei region,the areas near to Binzhou railroad, the north of Heiyupao and the north of Daqing are the favorable areas for oil and gas to accumulate and form oil and gas reservoirs.