COMPOSITE MIXTURES OF LIGNOSULFONATE REAGENT SYSTEMS WITH SILICON COMPOUNDS

Abstract

The relevance of the article is related to the study of the possibility of improving the quality of lignosulfonate systems used during the passage of intervals of swelling clay rocks. A feature of reagent systems based on lignosulfonates is their ability to inhibit the hydration processes of clay minerals and thereby reduce the risks of complications during the construction of oil and gas wells. The properties of the composition were studied on the basis of a mixture of lignosulfonate systems and silicon compounds using the example of ferrochromolignosulfonate (FHLS-M) and sodium silicate Na2SiO3 (SS). The objective of the study was to find optimal ratios of the components of the mixture by the method of experimental planning, as a means of constructing mathematical models and regression analysis to assess the magnitude and direction of the impact of various factors on the output parameters of the flushing fluid system. The research method consists in determining the stability of the solution parameters with varying temperatures from 20 to 190 °C in the aging cell for 5 h and conducting at least three parallel determinations for each ratio of reagents in the composition relative to the initial clay solution. The performed regression analysis of the composition of FHLS-M: SS showed that the greatest influence on the viscosity and filtration properties of the solution is exerted by the content of FHLS-M. However, in the temperature range of 80-190 °C, the ratio of FHLS-M: SS is justified, equal to 3%:5% (the addition of SS enhances the effect of the composition by more than 40%). In the temperature range of 20-120 °C, to maintain the conditional viscosity of the solution (CV) at least 60 s, a sodium silicate content of about 4 % is required, FHLS-M – within 3-5%. At temperatures of 80-120 °C and a value of CV = 60 s, the composition of the composition of FHLS-M: SS is 3%:4%, respectively; with an increase in temperature of more than 120 °C, there is a need to increase the consumption of FHLS-M. At the same time, in the temperature range of 80-190 °C, the ratio of FHLS-M: SS is justified at the level of 3%:4%, respectively. It was found that the optimal ratio in the temperature range of 20-190 °C, in the composition of FHLS-M: SS, is 0.75%:0.75 %, respectively, however, the conditional viscosity (CV) of the solution is no more than 35 s. A decrease in the filtration index (FI) of the solution at temperatures up to 80 °C is ensured by the use of less than 2% sodium silicate in the composition, and FHLS-M in the range of 2-5%.