COMPARATIVE ASSESSMENT OF CO2-SEQUESTRATION IN THE FARNSWORTH, TEXAS HYDROCARBON FIELD USING THE STOMP-EOR, TOUGHREACT, AND GEM REACTIVE TRANSPORT SIMULATORS
Some consistent results were observed in the model results. Temperature decreased and pressure increased during the injection phase, after which the trends reversed and pressure and temperature homogenized over time. All of the models predicted a sharp decrease in pH near the injection well, which inhibited carbonate mineral precipitation. All of the models predicted calcite to dissolve continuously and for dolomite to be a major mineral sink for CO2. All of the models predicted small changes in porosity over time, but too small to impact the permeability and fluid flow patterns significantly. The models differed in other respects. The models predicted significant differences in silicate mineral abundance. In the EOR scenario, oil was consistently predicted to be the main sink for injected CO2. In the saline aquifer model, either immiscible CO2 or aqueous solution could be the main sinks for injected CO2. The results of the study not only provide insights into the behavior of injected CO2 but also uncertainties in this behavior based on the degree of consistency in the outputs of the different numerical simulators.