Research On Theory And Application Of Downhole Vortex Deliquification Process

So far, liquid loading problem is very common in our country gas wells. For these, using the drainage gas recovery technology can help the gas wells producing. Downwhole vortex unloading process is one of the latest drainage gas recovery technologies. It has been already used in our country, but the theory research is not much. The working principle and active length calculating method of vortex tools by building a mathematical modeling was explained in this essay. Meanwhile, taking the 2-7/8 tubing as a using condition, the numerical simulations of different technical parameters and geometric parameters was done. At last, according to the common operating conditions and drainage gas recovery technologies, software of gas well unloading analysis system was compiled.In theoretical research, the flow of pipe with the vortex tool was analyzed. By comparing with the critical flow rate between the outside flow of inlet and outlet, it is proved that, using the vortex tool can make the critical flow rate 8-16% lower, which can improve the gas wells unloading capacity. Then, the two kinds of methods was derived by the using the vortex flow decay theory and film theory, which determine the method of estimating the active length of the vortex tool.In the numerical simulations, taking the 2-7/8 tubing as a using condition, it is conclude that, the increase of drops diameter, inlet velocity, liquid hold-up, downhole pressure and the decrease of gas density can improve the gas-water separation efficiency, and the influence of gas density is much greater. Besides, the results shows that when using the vortex tool in 2-7/8 tubing, it will get the best effect under these conditions:helix angle being 70°, the number of helix angle lead being 1.5, the column diameter being 45mm.