MODELING OF WATER-ISOLATING SYSTEM GEL TIME FOR OIL WELLS

Currently, a high water cut in wells is one of the main problems of the oil industry. Its presence leads to a decrease in the flow rate of wells, an increase in the volume of work connected with the dewatering and trans- portation of products, an increase in the number of annular flows in wells, the destruction of bottom-hole formation rocks and the formation of sand plugs. One of the available and effective ways to solve this prob- lem is the use of methods for limiting water inflow, and in particular, technologies for leveling the injectivity profile in injection wells. During these works fulfilling, an important characteristic is water isolat- ing system gel time, which is affected by various parameters. This is the time required for the gel to transition from a free fluid into a solid or semi-solid, after which its transfer becomes difficult. In this work, an organically crosslinked system containing an acrylate copolymer crosslinked with a polyamine was chosen as a water insulat- ing material. Different formulations were developed using 2 % and 5 % potassium chloride (KCl), used as an acidic agent. The gel time of vari- ous compositions was determined at temperatures of 60 °C and 88 °C. According to the research results, the corresponding dependencies were established. To quantify the degree of influence of these parameters on the gel time, factor analysis was performed, which showed that the temperature parameter had the greatest effect. Also based on the results of the research, a mathematical model was developed for predicting the gel time, which describes the mechanism by which the three parameters considered are affected: the concentration of the crosslinker, the concen- tration of the acidic agent, and temperature.