НЕСТАЦИОНАРНЫЙ МАССООБМЕН В ПОРИСТЫХ СРЕДАХ С ПОДВИЖНЫМИ И МАЛОПОДВИЖНЫМИ ФЛЮИДАМИ

Abstract

Hydrodynamic regularity under filtration in heterogeneous porous medium largely determine the displacement efficiency of hydrocarbons. There is a number of investigations describing process of isothermal filtration under immiscible fluids displacement taking into account capillary impregnation, analytical and numerical solutions were obtained. Traditionally it is assumed that a two-phase filtration takes place under certain flow rates and injection pressures only within residual water saturation to the maximum possible water saturation determined by the value of the fixed saturation. This paper presents the processes of mass transfer under hydrodynamic nonequilibrium in heterogeneous porous media. The effect of capillary forces on the process of immiscible fluids displacement in heterogeneous reservoirs can be decisive. The paper considers the fields of mobile and immobile fluids. In the first area in immobile pores a major influence on the shape of the free surface have a surface tension forces. In another area, a thin layer of oil carried along by the flow, takes into account the combined effect of capillary and hydrodynamic forces. To describe the motion of oil in the immobile area then used the equations of lubrication theory. Volume of high permeable containing the mobile phase is usually small compared to the volume of the structure with an immobile phase. Therefore, the system of pore matrix - high-permeable channel can be described as an ordinary porous medium - porous or fractured medium. In that case the effect of feeding of high-permeable channels from the system of blocks under unsteady flow have place. Therefore,we cannote that oil recovery increasing through water injection, providing rapidly entraining of oil, jammed in the pores under the influence of capillary forces.