Statistical characteristics of liquid injection by jet pump in the process of hydrocarbon production

Abstract

Purpose.To determine the effective range of pressure ratios in the working fluid at the inlet to the jet pump and at its outlet and to determine the numerical characteristics of the random variable – the injection coefficient, provided that the normal distribution law is implemented and rational values of the injection coefficient are achieved, with the determination of the probability of its implementation. The methods. The calculation is carried out using the statistical numerical characteristics of the injection coefficient and the justification of the initial conditions regarding the ratio of pressures at the inlet and outlet of the jet pump. Findings. The operating pressure range is set within (60...160) bar, which corresponds to the throttling pressure when the liquid passes through the nozzle of the jet pump within the limits accepted in the oil industry. The effect on the value of the injection coefficient separately of the pressure at the inlet and outlet of the jet pump, as well as the complex effect with the determination of the probable range of pressure at the inlet within 360...460 bar and at the outlet 330...336 bar, while -the injection ratio varies from 0 to a maximum value of 0.96. The range of variation of the injection coefficient within 3 σ with the centering of the random variable and the determination of the mathematical expectation with the value of 0.48 is constructed. The originality. It was found that within half of the mean square deviation, the established value of the probability of realization of the injection coefficient is 0.383. Within the mean square deviation, the established value of the probability of realizing the injection coefficient is 0.683, which confirms the high probability of realizing the injection coefficient with a centering of 0.48 Practical implementation. The obtained results of the calculations make it possible to substantiate the design parameters and energy parameters of the system of supplying the working fluid from the surface during the design of the pump and the development of the technology of its application with the achievement of rational values of the injection coefficient. This will increase the efficiency of the jet pump for cleaning the near-stem area of the oil well and will contribute to the increase of hydrocarbon production.