Research on factors influencing permeability oflow-permeability fracture-type reservoirs

In order to probe into the percolation law for the low-permeability fracture-type reservoir, the effect of such parameters as the formation pressure, the temperature, and the fluid property on the permeability of low-permeability fracture-type reservoirs is obtained, based on the experimental study and analysis on the core permeability of a fault block in an oilfield. The result shows that along with the increase of the formation pressure, fractures are gradually unlocked, and the permeability first reduces and then gradually increases. The fracture reopening pressure ranges from eight MPa to ten MPa. The correlation expression of permeability and formation pressure is obtained based on the quantitative fitting and regression of experimental curves. Core permeability gradually decreases as the temperature increases. The permeability of the same rock core to the formation water is higher than that to the pure water. The result can be a good theoretical reference to the selection of rational formation pressure and production pressure difference for the development of low-permeability reservoirs. 