Stress Sensitivity Analysis Of Two Kinds Of Deformed Media Reservoirs In Tight Sandstone Reservoir

During exploiting the tight sandstone reservoirs,the descent of formation pressure will induce the virtual stress increase,which makes the pore structure of the reservoir rock have experienced some changes and the permeability descent.In this paper,we did the casting thin sections of rock sample analysis sampled from the basin southwest Chang 8 reservoir in changing oilfield and it is found that the clay minerals in this area are distributed in the region.Select 3 pairs of two kinds of typical deformation medium rock samples to carry out carry out stress sensitivity experiment and test results show that the stress sensitivity of permeability of the rock sample mainly containing kaolinite is stronger than that of the rock sample mainly containing chlorite.Among the numerous influencing factors,the type of clay minerals microstructures plays a decisive role in stress sensitivity of reservoir.In the IPR sensitivity factor analysis of two kinds of deformed media reservoirs,firstly,the formula of oil well output considering stress sensitivity is derived.And then study the relationship between yield and the pressure difference.The output of oil well increases with the increase of the pressure difference,and decreases with the increase of the deformation coefficient of the medium.The production index with the production pressure difference is no longer linear relationship,and there is a maximum productivity index and the optimal production pressure difference.The relationship between deformation coefficient and effective overburden pressure is negative exponent.There is a permeability funnel near the bottom of the well,the bigger the deformation coefficient,the greater the loss of permeability near the bottom of the well.The depletion development numerical simulation results show that the stress sensitivity has a great influence on the yield of low permeability reservoir.Suggest that the advanced water injection measures are adopted in the low permeability reservoir.The effect of advanced water injection in the stress sensitive reservoir is obvious.Single well daily production and Cumulative oil production increased significantly,and the reservoir pressure is maintained at a good level.