Overall Structure Design And Optimization Of High Pressure Tubular Separator

Tubular separator is a newly developed separation technology in recent years.Its general idea is to complete multiphase separation under different working conditions and different processing requirements through the appropriate combination of multiple single-phase separators.This technology is mostly used for the three-phase separation of oil,gas and water.However,for the current tubular separation technology under high pressure and high water cut conditions,the separation cost increases due to the low separation efficiency of the selected separators at all levels and too many separation stages.In order to improve the separation efficiency,this paper designs and optimises the oil-gas-water three-phase tubular separator based on the idea of tubular separation.The main research contents and conclusions are as follows:(1)In the optimal design of model structure,the separator structure is divided into two parts: gas-liquid separation section and oil-water separation section.Based on literature research,hydrocyclone separator and elevation-type oil-water separator were selected as the structural models of the first and second stage separation.(2)Numerical simulation of the first stage of separation in a tubular separator was carried out by using the computational fluid dynamics software Fluent.In order to improve the separation efficiency,the control variable method was adopted to change the structural parameters of the first section of separation,such as the diameter of the overflow port,the insertion depth of the overflow pipe and the diameter of the bottom flow port.According to the simulation results,the pressure field,gas volume and velocity field in each case were analyzed.After comprehensive comparison,the overflow diameter of 30 mm,the insertion depth of50 mm and the bottom flow diameter of 20 mm were selected as the relatively optimal structural parameters.(3)According to the parameters of the first stage determined the size of the elevation-type separator of the second stage.and after many simulations,the variation trend of the oil and water separation efficiency with the change of its structural parameters was analyzed.It is found that within a certain range,the larger the horizontal position of the inlet of the separator is,the greater the separation efficiency will be,and the later the oil collecting chamber is,the greater the separation efficiency will be.Finally,the relatively optimal structural parameters in the elevation-angle oil-water separator were obtained by adding three groups of coalescated corrugated plates,the horizontal position of the inlet was 90%L,and the position of the oil collecting chamber was 75%L.The optimized separation efficiency reached 96.1%.Finally,the fields in the optimized separator were observed and analyzed.(4)The optimized separation first section and separation second section are connected with the UDF module in Fluent to form a new integrated tubular separation device.After the selection of relevant models,the integrated separation device is simulated and its operation is observed.After that,the influence of different oil and gas content on the separation of gas and oil phase under the same inlet flow was explored.Finally,the optimal gas phase working range of the equipment was found to be between 7%-13%.