Single well gathering and transportation process of produced fluid from high-CO₂ gasfield in Huangqiao

In order to efficiently recover and utilize the produced fluid from high-CO₂ gas wells in Huangqiao, thermodynamic state equation (PRSV state equation and WS mixing rule) and flash evaporation calculation theory were adopted for phase state calculation of the produced fluid from high-CO₂ gas wells in Huangqiao, which revealed the phase diagram feature of the high-CO₂ well flow in Huangqiao and the influence of CO₂ on the phase state of oil and gas hydrocarbon system. Specifically, the gas-liquid two-phase area, which is on the p-T phase diagram of oil and gas hydrocarbon system containing CO₂, decreases significantly with the increase of CO₂ mole fraction. According to the phase characteristics of the produced fluid, the surface treatment process of single well was established, and the operating parameters of key equipment (cyclone separator and CO₂ compressor) in the produced fluid treatment process were analyzed, concluding that all the currently selected operating parameters were in the reliable working area (single phase gas area) of cyclone separator. There was no liquid phase precipitation in the full working pressure and temperature range of CO₂ compressor. The established gathering and transportation process flow and operating parameters of equipment in Huangqiao high-CO₂ single wells have been verified to be reasonable, and on this basis, free water and liquid crude oil can be effectively removed from the high-CO₂ single well flow in this area. The process flow and operating parameters of equipment can be promoted and used in similar condition blocks of this area.