Foam for Enhanced Oil Recovery: Modeling and Analytical Solutions

Foam increases sweep in miscible- and immiscible-gas enhanced oil recovery by decreasing the mobility of gas enormously. This thesis is concerned with the simulations and analytical solutions for foam flow for the purpose of modeling foam EOR in a reservoir. For the ultimate goal of upscaling our modeling results to foam EOR in reservoir, it is important to determine whether strong foam created near an injection well can propagate to large distances from the well, where superficial velocity is much smaller. In experiments, creation of strong foam is triggered by an increase in superficial velocity; thereafter injection rate can be reduced to lower values and strong foam remains. We study strong-foam propagation with finite-difference simulations and Riemann solutions, applying the multiple- steady-states population-balance foam model of Kam (2008). Our simulations show that strong foam cannot directly displace the initial high-water-saturation bank initially in the reservoir at low superficial velocities; it pushes a weak-foam state with lower velocity that in turn displaces the bank ahead. Our traveling wave solutions show that strong foam propagates more slowly as superficial velocity decreases and stops propagating at yet lower superficial velocities, in agreement with experiment. Failure of propagation occurs at superficial velocities greater than that at which the strong-foam state disappears; it raises concerns for long-distance propagation of strong foam created near the injection well.Geoscience & EngineeringCivil Engineering and Geoscience