Injection of water into a porous medium saturated with steam

Abstract

This paper deals with injection of water into heated porous media saturated with steam. It is assumed that phase transformations occur entirely on the frontal surface which separates regions filled with water and steam. Two modes of injection are possible. In the first mode, which is realized at rather substantial differences between the initial temperature of the reservoir and the temperature of water being injected, the condensation of steam occurs at the interface. In so doing, the pressure at the interface becomes lower than the initial reservoir pressure, and, as a result, a minimum of pressure distribution occurs. The second mode, on the contrary, involves the evaporation of water being injected. The criterion used to distinguish between these two modes is determined. The critical condition is derived for the case when the temperature evolution in the region of percolation of liquid is largely defined by convective transfer. In so doing, the temperature distribution has three uniform domains with values equal to those of the temperature of liquid being injected, of the initial temperature of the porous medium, and of some intermediate temperature equal to the temperature at the interface, and the temperature differences in the porous medium are realized in two layers. The first of these layers is in the vicinity of the interface, and the second one, in the zone of percolation of water. For this case, which is realized at fairly significant pressure drops and a high permeability of the reservoir, self-similar solutions are constructed for plane and radially symmetric problems.