## 3 Results and Discussion
### Investigation of the Mechanism of Sediment Formation in Sediment-Gelling Compositions
This dependence is shown in Figure 2. An analytical approximation of this dependence was obtained and substituted into (1); thus, the dependence of the sediment volume on the concentrations of alkali and polyacrylamide was obtained in the following form (3):  
\[V_{sd}=0.3289\cdot C_{NaOH}^{0.716\cdot e^{11.502\cdot C_{PAA}}} \tag{3}\]  
Figure 1: The dependence of the amount of precipitate on the concentration of alkali at different concentrations of polyacrylamide (PAA) (colored lines indicate approximating curves for the obtained dependencies). Calculations were made according to this expression, and comparison with the actual experimental values showed their sufficient coincidence. The change in the amount of sediment upon contact of the polymer and alkali, depending on their concentration, is caused by the action of several factors. On the one hand, when alkali is introduced into the polymer solution, part of it interacts with polyvalent cations (Ca\({}^{2+}\), Mg\({}^{2+}\)) contained in water, as a result of which the poorly soluble hydroxides of the Ca(OH)\({}_{2}\) type precipitate as a finely dispersed solid phase. The other part of the alkali, being adsorbed on polymer macromolecules, does not participate in the formation of a precipitate [1]. Therefore, at low concentrations of alkali (0.1-0.15%), with an increase in the concentration of the polymer in solution from 0.025 to 0.15%, a decrease in the amount of sediment is observed due to the increasing possibility that part of the alkali may be adsorbed on the polymer. The same mechanism also operates up to an alkali concentration of 0.25% at polymer concentrations in solution of 0.025-0.075%, with alkali and polymer, respectively, in the ranges of 0.5-0.75 and 0.025-0.075%. And at high concentrations of both reagents, the volume of the precipitate increases. On the other hand, alkali facilitates the association of functional groups of the polymer into larger formations [1; 3], as a result of which they can precipitate. At the same time, the polymer is able to bind the individual, formed, dispersed particles to each other and also lead to their precipitation. Therefore, with an increase in the concentration of both alkali and polymer above the indicated limits, all of the above mechanisms come into play. As a result, the amount of sediment increases both in the form of poorly soluble hydroxides and large polymer-alkaline aggregates. Thus, the conducted studies have shown that by selecting the appropriate concentrations of polymer and alkali for each specific case of near-bottom-hole zone treatment, it is possible to control the amount of sediment formed and thereby increase the efficiency of limiting water inflows by SGCs. Analysis of the Results of Studies Devoted to the Study of the Filtration Characteristics of Polymer Systems  
In recent years, researchers have begun to pay serious attention to finding technological solutions to eliminate the consequences of water breakthrough through highly permeable interlayers of heterogeneous reservoirs while using the so-called flow-diverting technologies (FDT) [4; 5; 6; 7; 8]. Most of the functions of FDT are aimed at the formation of a water barrier by pumping the appropriate compositions into injection wells. As a result of this, the volume of water injection is redistributed, both in terms of thickness and area of the deposit, and the previously unexplored or poorly covered formation zones are connected to the development by waterflooding. It should be noted that a polymer solution plays one of the main roles in the mechanism of the formation of a water-insulating shield. In some of the studies carried out, the main focus of attention was the movement of compositions based on a PAA polymer solution of the brand \"FP-307\" and a chromium acetate cross-linker  
Figure 2: Dependence of parameter \(b\) of expression (2) on the concentration of polyacrylamide. in a porous medium.