Numerical and orthogonal optimization study on structural parameters of surface jet boosting tools

Abstract

Low-pressure gas wells are typically produced with the assistance of booster compressors to reduce wellhead pressure further, yet this approach incurs high operational costs. Therefore, it is of crucial significance to utilize the wasted energy from high-pressure gas wells to drive the production of low-pressure wells and exert the synergistic pressurization effect between gas wells. Current research on gas ejectors still faces challenges including unclear mechanisms of the pressurization process, lack of mature dimensional design methods, and poor theoretical universality under different working conditions. In this paper, an optimization study is carried out on gas ejectors. A CFD numerical model is established covering mesh generation, turbulence model selection, discretization scheme setting, and boundary condition configuration, and the simulation accuracy is validated against field test data. The distribution laws of the internal pressure field and velocity field of the ejector are systematically simulated. The effects of key structural parameters (nozzle outlet chamfer angle, nozzle-throat distance, length and diameter of the mixing tube, length and angle of the diffuser) on entrainment performance are analyzed, and the variation trends of the ejection coefficient influenced by each parameter are obtained. Field tests were conducted based on the optimization results, which demonstrated that the wellhead pressure of low-pressure gas wells decreased significantly and the production increased substantially, verifying the practicability of the optimization scheme. This study provides a theoretical basis for the structural optimization of gas ejectors and possesses important engineering application value for improving the recovery efficiency of low-pressure gas wells.