Simulation of Water and Condensate Blockage and Solvent Treatments in Tight Formations Using Coupled Three-Phase Flash and Capillary Pressure Models

摘要

Water and condensate blockage near production wells in unconventional reservoirs can significantly reduce oil and gas production rates. This paper presents a new approach for more accurate modelling of liquid blockage in tight oil and gas reservoirs and investigates the use of solvents for blockage removal. A cubic equation of state is used to model the phase behavior of three-phase mixtures of solvent, hydrocarbons and water. The three-phase flash model is coupled with a rigorous three-phase capillary pressure model to account for the effect of capillary pressure. The capillary pressure function includes the impact of several important petrophysical properties such as pore size distribution and wettability. A compositional simulator is used to simulate the effectiveness of using methanol, dimethyl ether or CO2 to remove liquid blockage and increase production rate.