A New Waterflooding Characteristic Curve for Naturally Fractured Sandstone Reservoirs

Characteristic curves have found wide applications to analysis and prediction of waterflooding behavior for sandstone reservoirs. Based on the theory of water-oil two-phase flow in dual porous media and taking advantage of the relative permeability curve for naturally fractured sandstone reservoirs, a new waterflooding characteristic curve was derived with an explicit mathematical expression. Verified by physical simulation, numerical simulation and field case, the curve for fractured reservoirs will upwarp at high watercuts, rarely seen in that of non-fractured sandstone reservoirs. In order to improve the quality of analysis and prediction, it is suggested to utilize the new characteristic curve for naturally fractured sandstone reservoirs rather than the conventional curves for non-fractured sandstone reservoirs. Key words : Fractured sandstone reservoir; Waterflooding characteristic curve; Relative permeability curve; Physical simulation; Numerical simulation