Stability analysis of non-isothermal oil displacement by steam-water mixture

To solve the relevant problem of analyzing the stability of non-isothermal oil displacement by a vapor-liquid mixture, a criterion is introduced that considers the densities of the oil and the vapor-liquid mixture, the viscosity and the relative phase permeability of these phases. A system of equations of mechanics of multiphase media is written considering nonisothermal filtration and cylindrical symmetry. The discontinuity ratios for the law of conservation of mass, momentum, and energy are considered. The presence of a critical pressure gradient has been established, at which the displacement process is still stable. The influence of fluid viscosities and relative phase permeabilities on the value of the introduced criterion is analyzed. It is shown that this value increases linearly with an increase in the ratio of oil viscosity to steam viscosity.