Efficiency and Pressure Recovery in Hydraulic Jet Pumping of Two-Phase Gas/Liquid Mixtures

Abstract

Summary Hydraulic jet pumping of gas/liquid mixtures was studied experimentally, and a mathematical model is proposed to extend the standard single-phase model for predicting efficiency and pressure recovery to suction fluids with gas/liquid ratios up to 2, 200 scf/STB. The experimental program comprises 616 low-pressure tests in a plastic model pump designed for flow visualization and measurement of pressure profile along the throat and diffuser, and 373 high-pressure tests on a stock pump. For the high-pressure tests, power fluid was supplied at 200 to 3, 000 psi and at 200 to 860 B/D; air was supplied from 0 to 185 Mscf/D. Discharge pressures ranged from 800 to 2, 000 psi. The mathematical model extends a previous model that describes single-phase performance from mass and energy conservation. The empirical loss coefficients for the nozzle and throat/diffuser are replaced by a nondimensional expression that varies as three dimensionless parameters: nozzle-to-throat area ratio, discharge-to-power-fluid pressure ratio, and air/water ratio (which usually is in conventional units of cubic feet per stock-tank barrel but is, of course, basically dimensionless). The loss coefficient for the nozzle is constant, but for the throat/diffuser it is a constant plus a product of a constant times the three parameters, each to a power. Compared with the standard model, which always overpredicts pressure recovery and thus efficiency, the new model reduces the standard error of the estimate to 18% of its former value.