Traditional methods for increasing oil recovery for deposits of high-viscosity oil and heavy oil are aimed at reducing the viscosity of oil and increasing its mobility through the use of methods based on heat injection into the reservoir. In some cases, thermal methods do not show a good result, for example, for thin-bedded or deep-seated formations. Currently, specialists use chemical methods for stimulating the formation as the most commonly used means of increasing the efficiency of the oil field development process. One of the most commonly used chemical methods is polymer flooding. Traditionally, the economically advantageous area of application of this method is: 1) a high mobility ratio in the case of classical water flooding, 2) high heterogeneity of the formation, 3) a combination of these factors. In these cases, polymers can be injected both in the form of conventional polymer solutions and in the form of polymer systems crosslinked in formation, in order to increase the oil recovery due to the thickening of the displacing fluid or the reduction of phase permeability along it, as well as by puncturing the zones of increased permeability. Classical polymer flooding involves the injection of a large-sized rim polymer solution to reduce the mobility ratio. It is very important in the design of polymer flooding to find a rational concentration of polymer (substance) in the polymer solution, to determine the viscosity of the polymer solution, the size of its rim, the injection regime, etc. In this article, the authors considered in detail such a parameter as the viscosity of a polymer solution, and also proposed an express method for determining its rational value.
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