Gas-Water Two Phase Flow Simulation Based on Pore Network Model for Reservoir Rocks

Abstract

The relative permeability and capillary pressure are essential to investigate fluid flow in porous media, in terms of studying seepage characteristics of gas -water for CO2 emission reduction through deep saline sequestration. In this paper, we presented gas -water phase flow numerical simulation based on pore network extractions of four rock samples. The influence of temperature, pressure and pore structure on relative permeability and capillary pressure were carefully investigated. Analysis of evaluated results demonstrated that pore structure has significant impact on relative permeability and capillary pressure both for gas/water drainage and imbibition cycles. However, the influence of temperature and pressure on relative permeability and capillary pressure for drainage cycle is neglect-able, while during the imbibition cycle, the gas phase relative permeability is decreasing with increasing pressure and temperature, while capillary pressure and wetting phase relative permeability are decreasing with increasing pressure and increasing with increasing temperature. That might cause by change of rock wetting behavior and interactions between fluid-gas-rock as temperature, pressure change which has more impact on gas flooding process than water flooding. After comparing numerical simulation results of drainage cycle based on Berea sandstone sample to the literature, it is seemed that numerical simulation based on pore network extractions is more efficient and economical method of studying seepage characteristics of gas -water at CO2 reservoir storage conditions.