Laboratory surfactant/alkali and hot water floods have shown great potential in increasing oil recovery for reservoirs that are naturally fractured and have low permeability and mixed-wet matrix rocks. The mechanisms for oil recovery are the combined effects of reduced interfacial tension, reduced mobility ratio, and wettability alteration. These processes have not been tested on either pilot- or field-scale mainly due to lack of complete understanding of the complex mechanisms involved. Surfactants have been used to change the wettability with the goal of increasing the oil recovery by increased imbibition of the water into the matrix rocks. Reservoir simulation is required to scale-up the process from laboratory to field conditions and to understand and interpret reservoir data.
Our goal is to model surfactant spontaneous imbibition experiments in carbonate cores to better understand and predict the oil recovery mechanisms as a function of wettability, to develop scale-up methodology, and to aid in development of a correlation for degree of wettability alteration. These simulations are performed using either explicit fractures or the multiphase, multicomponent dual porosity model in UTCHEM.