ANALYSIS OF DISSOLVING ABILITY OF LOWER ALCOHOLS AND ESTERS AQUEOUS AND HYDROCARBON SOLUTIONS TO ORGANIC MATTER OF BAZHENOV FORMATION ROCKS

Abstract

This work is devoted to studying the characteristics of treatments with organic solvents on bazhenov formation rock samples, which contains a large amount of unconverted organic matter (kerogen, bitumen). This article contains the results of studying the dissolving abilities of individual low-molecular alcohols and esters, and solutions of these compounds in water and in a non-polar aromatic solvent (petroleum solvent). Among the individual solvents studied, esters of acetic acid showed the greatest dissolving ability; alcohols are less active. Petroleum solvent slightly dissolves the rock’s organic matter and needs the addition of more polar organic compounds. The dependences of dissolving ability of alcohols’ hydrocarbon solutions on alcohol concentration is extreme, with a maximum of 10 wt.%. Based on the obtained results, the mutual influence of solvents in the hydrocarbon fluid was additionally evaluated. It has been established that solutions of isopropanol and aromatic solvent show a synergistic effect to the dissolution of rock organic matter more than hydrocarbon solutions of esters. For the compositions that showed the greatest dissolving ability, a qualitative and semi-quantitative analysis was made for establishing changes in the composition of rock samples after extraction using X-Ray diffraction and Fourier-transform infrared spectroscopy. It is shown that mixtures of polar and non-polar solvents provide a more regular extraction of aliphatic and aromatic components of rock organic matter. Systems containing petroleum solvent, isopropanol and isopropyl acetate have been identified as the basis for the development of process fluids for increasing oil recovery in organic-rich reservoirs.