Numerical simulation research on eddy current drainage gas recovery technology

In order to facilitate the eddy current drainage gas recovery technology being widely used in China, simulation research on eddy current instrument characteristics was carried out. The mathematical model of eddy current tools draining process was established to study the eddy field triggered by the cyclone of the tools. The simulation figured out the flow field structure and characteristics of gas-liquid spiral vortex flow under different Reynolds numbers and liquid holdup conditions; besides, the influence of gas velocity on liquid membrane spiral flow and variation of spiral flow intensity also obtained from the simulation results. The study had revealed that the gas-liquid two-phase fluid was transformed into kind of annular flow by vortex tools, and the center of the wellbore moved up in a continuous form of gas column accompanied liquid membrane near the wall spiral upward movement. These flow structures reduce string friction and improve gas liquid carrying capacity.