## 1 Introduction  
As is known, production wells are often completely flooded, while a significant part of the oil reserves still remain undeveloped. These features are inherent in various fields. Under these conditions, the most reliable way to increase oil recovery is to limit water inflow using modern technologies and chemicals [1, 2]. In turn, for these methods to be effective, a waterproofing shield with a radius of a large length is required. One of the technologies that enhances the efficiency of bottom-hole zone treatments by reducing the permeability of the washed zones of the bottom-hole formation and reducing the degree of its heterogeneity is the sediment-gelling composition--SGC. The action of such compositions is based on the creation of an insoluble sediment and polymer gel in the pore space of the bottom-hole formation zone, thereby blocking or reducing the permeability of water-washed intervals. Such technologies include the processing of the near-bottom-hole zone (NBHZ) with SGCs based on water-soluble polymers and alkalis. This technology is based on a reaction between two reagents in the reservoir, which, when mixed, interact with each other and reservoir water and form a precipitate and a gel in the near-wellbore region, preventing water from entering the well. A special case of this technology is the reaction of the polymer with formation water. In addition, as noted in the works [2; 3], the efficiency of using SGCs based on water-soluble polymers and alkalis increases significantly due to the presence of a polymer that has flocculating properties, which makes it possible to bind the individual dispersed particles formed in the reservoir to themselves and to the rock of the reservoir, thereby further increasing the isolation effect. However, the success of works on waterproofing with SGCs is still not high enough. It is possible to increase the effectiveness of water shutoff works due to a more reasonable choice of SGC for specific conditions of the treated wells [2]. As is known [3; 4], the efficiency of NBHZ treatments with SGCs depends on their good selective filterability in zones with high water saturation, allowing for the creation of water-insulating barriers/shields in the desired direction and to a sufficient depth, and the controllability of the process of water-shedding of the flooded section of the reservoir according to the degree and duration of blockage and water-insulating properties of the formed screen [5], determined by the rheological and filtration characteristics of the SGC. Currently, most of the world's oil fields are at a late stage of development, which is characterized primarily by an increase in water cut and a decrease in oil production [5; 6; 7]. Well water cut is a serious and widespread problem in the oil industry, and it is the subject of numerous studies. In published works, researchers are trying to find out the causes of water manifestations and outline the sequence of studies to develop measures for their prevention and elimination. If we add the uncertainty of the conditions for modeling and decision making to the above, then the complexity of solving this problem becomes obvious. This explains the great attention of researchers on this problem. Like any other process that is a serious problem, watering also requires the establishment, proper understanding, and analysis of the causes of excess water supply [8]. To date, methods have been developed and proposed, according to which problems and their nature are determined using modern diagnostic methods, which make it possible to prevent and eliminate the source of excessive watering. Thus, in order to increase the efficiency of field development and reduce the cost of processing and disposal of produced water, it is necessary to control the process of water cut in production correctly and in a timely manner, with a preliminary study and the establishment of its causes [9; 10].