Study of the performance of liquid-gas ejectors for pumping water-gas mixtures into the reservoir

When pumping water-gas mixtures into a formation to enhance oil recovery, various equipment configurations are used with pumps, compressors, mixers, dispersers, etc. Previous studies showed the feasibility of using associated gas to enhance oil recovery using pump-ejector water-gas treatment technologies. The characteristics of liquid-gas ejectors, being key elements in these technologies, have not yet been fully studied. The characteristics of ejectors are affected by the processes of suppression of coalescence of gas bubbles in liquid, which depend on the absolute pressure in the flow, the concentration and composition of dis-solved electrolyte salts, the foaming properties of the liquid, etc. In order to experimentally evaluate the parameters of liquid-gas ejectors under changing operating conditions, bench studies were conducted for various pressure values in front of the nozzle and in the receiving chamber. When processing the experimental data, the parameter of the dimensionless relative average integral feed was used, taking into account the decrease in the volumetric gas flow rate as the pressure in the flow part of the ejector increases. These studies showed that in order to increase the efficiency of water-gas treatment in the pump-ejector systems, it is advisable to use liquid-gas ejectors with geometric ratios of the mixing chamber diameter to the diameter of the diaphragm nozzle in the range from 1,73 to 2,73. The values of the maximum efficiency of the ejectors range from 37,4 to 40,7 %, the average integral injection coefficients range from 1,4 to 3,9, the relative dimensionless pressure drops range from 0,09 to 0,21. © 2025 Elsevier B.V., All rights reserved.