The article describes a physical and mathematical cluster precise model and a method for calculating the flow of a two-phase mixture “oil — aqueous solution of surface-active substances” in the pore space of rocks. This method allows us to predict the effect of the type of aqueous solution of surface-active substances and the temperature of the solution on the type of relative permeabilities (RPP). The results of an experimental study of stationary two-phase fluid filtration in a reservoir model through a composite column of core samples are presented. A method is given for determining the relative permeability functions using additional reagents based on the obtained generalized experimental data and calculating pressure losses due to friction, local resistances, and interfacial interaction during the flow of oil-water mixture in the pore channels. Formulas are proposed for calculating losses from interphase interaction taking into account the influence of the type of surfactant and formation temperature. The dependences of the relative amplitude of pressure loss on interfacial interaction and the position of the maximum loss of the bell-shaped curve on the type of surfactant, formation temperature and adhesion work are obtained, which allow approximating the magnitude of pressure loss on interfacial interactions taking into account surfactants and temperature. The effect of temperature on the type of relative permeabilities is shown. It was established that the use of the studied aqueous surfactant solutions instead of water for oil displacement leads to a decrease in the residual oil saturation in the core due to a decrease in interfacial tension at the oil-water interface, which as a result leads to an increase in oil recovery.

A series of works was carried out to modernize the domestic automated software-measuring complex, designed to find the function of relative phase permeabilities in two-phase oil-water filtration, in order to equip it with the additional ability to filter gas together with two fluids. The creation of a software-measuring complex that allows to study three-phase filtration is an urgent task of a complex analysis of a field. Complexes produced by the industry with the possibility of three-phase filtration have a high cost. In this regard, there is a need to create a structurally simple and low-cost method for gas filtration, which is the subject of this work. In order to carry out gas filtration in the software-measuring complex, an intermediate stainless steel tank is installed in the area intended for creating reservoir pressure. Thus, part of the gas from the cylinder goes to the back pressure regulator, thereby forming reservoir pressure, and part is diverted to an intermediate reservoir. A pressure regulator is installed to regulate the gas flow. In this variant, gas is supplied directly to the end of the core holder in parallel with the water line, so fluids and gas are directly mixed in the body of the core holder. Methodical experiments on filtration of a gas-liquid mixture with subsequent determination of the volumetric flow rate of gas using the equation of state of a real gas were carried out. An analysis was made of the possibility of using this modernization of the installation for further study of three-phase or two-phase filtration.

To generalize the experimental data on the displacement of oil by aqueous solutions of surface-active substances (surfactants) at temperatures of 40, 60, 80 °C, we studied the influence of an additional parameter of the ratio of the work of adhesion during the displacement of oil by water to oil adhesion during the displacement of an aqueous solution of surfactant W = Ww/W. This parameter characterizes the intensity of mass transfer of oil particles from the surface of the rock using surfactants at different temperatures. The parameter W in combination with the capillary number Ca characterizes the value of residual oil saturation in oil reservoirs. A criterion equation is obtained that allows one to calculate the displacement coefficient from two dimensionless parameters: the capillary number and the relative work of oil adhesion.

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