Numerical Simulation of Non-Isothermal Two-Phase Flow in Oil Reservoirs, Including Heated Fluid Injection, Dispersion Effects, and Temperature-Dependent Relative Permeabilities

This study addresses the numerical simulation of non-isothermal two-phase water-oil flow in oil reservoirs. The problem of heavy oil recovery by reservoir heating (via heated fluid injection) is investigated, aiming to reduce oil viscosity and increase its mobility. The governing equations are formulated in terms of non-wetting phase pressure (oil), wetting phase saturation (water), and reservoir average temperature, without assuming local thermal equilibrium. Temperature-dependent relative permeabilities are considered. The Finite Volume Method is employed, and the resulting algebraic equations are linearized using the Picard method. The linearized discretized equations are solved sequentially for pressure, saturation, and average temperature, utilizing the Preconditioned Conjugate Gradient (pressure and average temperature) and Preconditioned Stabilized Biconjugate Gradient Method (saturation). After validating the numerical results, a sensitivity analysis is performed using a reservoir with slab geometry. The results demonstrate the positive impact of reservoir heating on heavy oil recovery.