Energy reduction and efficiency separation method of associated gas in oilfield based on EOR-CO2

Abstract

Cryogenic distillation is considered to be the most promising technology for the treatment of CO2-EOR gases, but it is an energy-intensive process. Considerable scientific efforts are being made to reduce energy consumption in cryogenic distillation and to improve process efficiency. Therefore, this study proposes a unique low-temperature distillation process. The novelty of the designed distillation process lies in the fact that using a small amount of refluxed liquid CO2 mixed with untreated oilfield-associated gas into the distillation column reduces the process energy consumption and improves the rectification effect. The sensitivity analysis of different design key parameters of the system is carried out using ASPEN HYSYS, and the energy consumption is regarded as the key function of this cycle optimization. The simulation results show that the optimized low-temperature distillation process has lower energy consumption and better distillation results. Compared with the traditional process, the product purity of the optimized process increased from 94.01% to 94.82%, the product recovery increased from 95.87% to 98.46%, The energy consumption of the reboiler and condenser of the distillation column was reduced, and the total energy consumption was reduced from 1.147MJ/kg to 1.001 MJ/kg.