INCREASING EFFICIENCY OF THE DISPLACEMENT OF HIGHLY RESINOUS OILS BY POLYMER SOLUTIONS

Abstract

The article presents the experimental results of studies of the filtration properties of oils from fields with a high content of asphaltene-resinous substances. Experimental studies of the filtration process of deposits with a high content of asphaltene-resinous substances have established that in low-permeability, unlike high-permeability reservoirs, the beginning of filtration proceeds according to a nonlinear law, and with an increase in the pressure gradient, the nonlinearity turns into a straight line corresponding to the Darcy law. In addition, the results of experimental studies on the displacement of oil from fields with a high content of asphaltene-resinous substances by polymer solutions on artificially created reservoir models are presented to determine the concentration of the polymer solution and the size of the slug to increase oil recovery from reservoirs. Experimental research on oil displacement by polymeric solutions were carried out on reservoir models filled with quartz sand, while the analyzed deposits are represented by carbonate limestone rocks. The results obtained on the oil displacement by polymer solutions on reservoir models with terrigenous reservoirs are considered possible for use on objects with carbonate reservoirs with a qualitative justification for the introduction of the polymer flooding method. Experimental studies on the oil displacement from fields with a high content of asphalteneresinous substances with a thickened water rim have established that this method gives the greatest increase in anhydrous and ultimate oil recovery, within a change in the concentration of the polymer solution of 0.2-0.4%, with a rim size of more than 70% of the oil-saturated reservoir volume. Studies on the displacement of high-viscosity oils with polymer solutions have shown that the use of this method of increasing the oil recovery factor in practice is not always economically feasible, due to the need to provide high injection pressures and a high concentration of an expensive polymer solution.