Dynamic Capillarity During the Water Flooding Process in Fractured Low Permeability Reservoirs

Abstract

Capillary pressure and relative permeability are the two main factors determining the multiphase flow in oil and gas reservoirs. Dynamic capillarity, which includes the dynamic capillary pressure and the dynamic relative permeability, should be considered when performing waterflooding in low permeability oil reservoirs. To stimulate the production, hydraulic fracturing has been applied in low permeability oil reservoirs. In this work, dynamic capillarity in fractured low permeability reservoirs were investigated through numerical simulation, which applied the capillary pressure and relative permeability data obtained from steady and dynamic waterflooding experiments. The numerical simulation conducted sensitive analysis using CMG. The results show that if the steady data are used in the prediction, the oil saturation reduces more evenly and more quickly, and the production capability of the reservoir is overestimated. Moreover, the production well will be predicted to breakthrough earlier, with a higher breakthrough water flow if the dynamic capillarity is neglected This work demonstrates the importance of considering dynamic capillarity in fractured low permeability reservoirs, and provides another perspective to predict the production in fractured low permeability reservoirs.