Nonlinear percolation feature of low permeability reservoirs and its effect

In view of the high filtration resistance and poor water injection results of low-permeability oil reservoirs,this paper derives a mathematical equation of percolation for low-permeability reservoirs according to the experimental data of physical models,and studies the percolation features and regularity of oil and water.Results show that the starting pressure gradient of the percolation exists in low-permeability reservoirs.It is inversely proportional to permeability,but is directly proportional to ultimate shear stress of oil.The lower the permeability is,the greater the extent of single-well output decrease is.What’s more,the extent of single-well output decrease increases as the ultimate shear stress becomes bigger and the distance between wells gets larger.So reservoirs can be reconstructed effectively by fracturing and drilling horizontal wells.And the results of developing low-permeability reservoirs can be improved by lowering shear stress of oil and applying small well spacing and greater production pressure difference.