ENGINEERING OF LIQUID-GAS EJECTOR USING NUMERICAL SIMULATION

Abstract

The article deals with the development and application of the technology of injection of low-pressure associated petroleum gas (APG) into the reservoir through the reservoir pressure maintenance system (RPMS) in connection with the entry into force of the Russian government decree on the mandatory utilization of 95 % of produced APG. The technology under consideration, the key element of which is a liquid-gas ejector (LGE), makes it possible to achieve this level with minimal investment, in the shortest possible time and to stop flaring APG at flares remote from the central oil and gas treatment facilities of oil and gas production facilities. LGEs have a relatively simple and reliable design due to the absence of moving elements.At present, there are known LGEs of classical designs, in which the level of hydrodynamic losses can reach 40–60 %. High hydrodynamic losses make it inexpedient to use such ejectors at small fields operated at a late stage of development, remote from the central oil and gas treatment facilities, due to the limitations of the existing equipment complex and the allowed operation mode of the injection well stock. To ensure the possibility of including LGE in the RPM system it was required to develop a new design of LGE, allowing to reduce hydrodynamic losses up to 30 %, as well as to ensure the maximum possible percentage of APG utilization. The article is devoted to the development, calculation of geometry and operating mode of LGE using numerical modeling in ANSYS environment.Modeling of the flowing part of the main elements of LGE (confuser nozzle, diffuser throat and gas channel width) at different values of parameters directly affecting the level of hydraulic losses is carried out. The results of calculations of numerical simulation of LGE allowed to optimize the dimensions of the internal geometry of LGE, thus it was possible to develop a new device for the required initial data, which will reduce the level of hydraulic losses up to 30 % and ensure the involvement of the maximum volume of gas in the RPM system.