Productivity of Micro-fractured Ultra-low Permeability Reservoirs

Based on the motion equation combining the pressure-sensitive effect and threshold pressure gradient, an integrate mathematical model of stable percolation in radio direction for micro-fractured ultra-low permeability reservoirs was established. And the analytical solution was used by pseudo-pressure transformation. Compared with the known formula, the correctness and universal validity were confirmed. The nonlinear influence of some factors on productivity, productivity index, and nonlinear factor are analyzed by using examples, these factors include the threshold pressure gradient, deformity coefficient, well spacing, and producing pressure drop. Some vital conclusions are acquired as following: the smaller the threshold pressure gradient, deformity coefficient, well spacing are, the larger the producing pressure drop is, the higher productivity would be obtained.