Theoretical and experimental analysis of gas-water relative permeability in tight gas

The effect of drawdown pressure on relative permeability is theoretically and experimentally investigated in this paper. A novel predictive model for gas-water relative permeability on the basis of the fractal theory was derived and the corresponding gas flooding tests were conducted. The predictions of relative permeability by the proposed model were validated by comparing with the conducted experiments. Both theoretical and experimental results indicate the significant effect of driving pressure on relative permeability. The predicted and experimental results demonstrate that lower immobile water saturation, wider two-phase region and higher water relative permeability corresponds to the higher drawdown pressure. © 2015, Science Press. All right reserved.