Displacement of high-parafin oil from formations by injected cold water

When cold water is injected into reservoirs, the reservoir temperature near the injector wells decreases and becomes lower than the wax saturation temperature of the oil. As a result, wax is precipitated from the oil in the porous medium of productive horizons, negatively impacting the development of oil reservoirs. The need to take into account the characteristics of oils and reservoir systems when designing the development of oil fields applies both to deposits of high-viscosity oils, in which, with increasing the reservoir temperature, viscosity decreases and oil mobility increases, intra-reservoir hydrodynamic resistances decrease, which improves the flow of fluids to producing wells, and to deposits of low-viscosity oils saturated with paraffin. The article addresses the question of the effectiveness of hot water injection. Hot water injection is only meaningful when the oil (or gas equivalent to oil) consumption for heating the water is less than the potential oil losses during cold water injection. The problem of research on cold water injection is relevant and necessary to optimize oil production processes. Changes in the reservoir pressure and temperature are important in assessing the effectiveness of the flooding method to increase oil recovery at the Uzen field of the Republic of Kazakhstan. The paper presents theoretical models based on real data that were used for calculations. The criteria for the effectiveness of hot water injection include such indicators as an increase in oil production, increase in the reservoir pressure efficiency, decrease in oil viscosity to improve its flowability, as well as a reduction in production costs.