Multiphase flow mobility impact on oil reservoir recovery: An open-source simulation

This work uses Computational Fluid Dynamics (CFD) to simulate the two-phase flow (oil and water) through a reservoir represented by a sandbox model. We investigated the influence in the flows of water having higher and lower mobilities than oil. To accomplish this, we also developed a dedicated solver, with the appropriated equations and representative models implemented in the open-source CFD OpenFOAM platform. In this solver, the black-oil model represented the oil. The results show that the Buckley–Leverett water-flood equation is a good approach for the three-dimensional flow. We observe that the water wall front is mixed to some extent with the oil and evolves obeying an exponential law. Water with mobility lower than oil is not common. However, in this case, the oil recovery is improved and the amount of injected water is reduced. The results comparing different mobilities show that a careful economic assessment should be performed before the field development. We have shown that the low water mobility can increase, as in this studied example, the water front saturation from 0.57 to 0.73, giving a substantial improvement in the oil recovery. The reservoir simulation can provide all process information needed to perform an economical assessment in an oil field exploration.