Study of the Rheological Characteristics of Sediment-Gelling Compositions for Limiting Water Inflows

In view of the poor knowledge of the applicability of sediment-gelling compositions (SGCs) in waterproofing the bottom-hole zone of wells, work in this area of research is one of the most promising in waterproofing today. The key goal of this work is to study the prospect of using SGCs for waterproofing as well as to calculate the rheological characteristics of the proposed SGCs depending on variations in the components of their composition (alkali and polymer). In the course of our studies, it was found that the key factors influencing the rheological characteristics of SGCs are not only the variation in the ratio in the composition of alkali and polymer but also the degree of salinity of the formation water, which must be taken into account when developing waterproofing. During this research, it was found that due to the absence of calcium and magnesium ions in fresh water, the proposed polymers have good solubility (the exponent in the rheological model is equal to or close to unity), which leads to an increase in the viscosity of solutions. The dependence of changes in the rheological constants of SGCs on such parameters as temperature and alkali concentration have been established. It was determined that an increase in the solution temperature leads to an increase in the rheological constant n from 0.8 to 0.92 (at a polymer concentration of 0.05 and a NaOH concentration of 0.1), while a variation in the NaOH alkali concentration from 0.1 to 0.75 leads to similar changes in one measured temperature range. The results obtained can be used in the future to evaluate the use of SGCs to create barrier waterproofing in the bottom-hole zone of wells during oil production.