Experimental Study on the Effect of Reservoir Physical Property on Pressure Sensitivity of Low Permeability Reservoirs

The rock pressure sensitivity was one of the major factors inducing poor effect in low permeability reservoirs,to study the effect of reservoir physical property on the pressure sensitivity in low permeability reservoirs,the effects of permeability,heterogeneity and fractures on the rock pressure sensitivity were studied through laboratory simulation.The results show that the lower the permeability is,the stronger the sensitivity is,and permeability loss is mainly at the initial stage of an effective pressure increase.The permeability of heterogeneous rock sample is between single layer with high or low permeability,its test result of pressure sensitivity is stronger than that of a parallel rock sample.The permeability loss in fractured reservoir is more greater than that in matrix reservoir,its loss degree is related to the permeability of meddle-level matrix in fractured cores.The lower the permeability of matrix is,the bigger the loss of permeability in fractured cores is,conversely,the loss is smaller.