Numerical simulation without using experimental data of relative permeability

This study proposes a numerical simulation approach without direct specification of relative permeability functions. Using this approach, it is not necessary to impose relative permeability functions as input to the simulator in order to conduct the numerical simulations of two-phase fluid flow. Instead only capillary pressure data need to be imposed and the relative permeabilities can be calculated consistently using specific models. Example numerical simulations at both core and reservoir scales were conducted to test the technique without the direct input of relative permeability functions from experimental data. The results showed that the production performance calculated from the numerical simulations without the input of relative permeability functions was almost the same as the experimental data. Using the method proposed in this study, the effects of pore size distribution index and entry capillary pressure on oil recovery by gravity drainage were investigated numerically at both core scale and reservoir scale. The technique may be especially suitable for reservoirs in which it is difficult to measure relative permeability curves. Such reservoirs include gas-condensate reservoirs, extremely low permeability reservoirs, and geothermal reservoirs. The proposed technique may also be useful to upscaling, numerical simulation while drilling, and other areas.