The Research On Vortex Drainage Gas Recovery Technology Of Low-Yield Oil Wells

With the domestic oil and gas fields coming into a stage of further development, the energy of the formation is getting smaller and smaller, so capacity of natural gas carrying liquid is getting worse under the ground. When speed of natural gas is less than the critical speed of lifting the liquid to the ground, the lifts force fluid suffered is not enough to bring it out of the well in the wellhole. The liquid begins to accumulate at the bottom of the wellbore in the form of droplets, and gradually merged as effusion. When the effusion reaches a certain level, the production of natural gas wells will have declined sharply, or even discontinued. In order to continue to exploit the underground natural gas, measures need to be taken to drain the liquid from the bottom of the well. And traditional drainage process, need to inject additional energy, greatly increased the cost of exploit. Therefore, develops the vortex drainage gas recovery process with the characteristics of high efficiency and low pollution, low cost.The function of the vortex drainage gas recovery process is mainly realized by a vortex tool with a spiral line. The parameters of the vortex tool have a great influence on the underground gas-liquid separation effect. this mainly research the separation effect of different parameters (center body diameter, guide of rotation, lead, spiral angle, spiral line height, spiral line width, etc.) of vortex tool under different downhole working conditions(gas-liquid ratio, flow velocity, etc.). Through computer simulation technology, simulates the gas-liquid separation effect and the law, which tool spiral angle is 55°,45°,50°,60°, under the working conditions which gas-liquid ratio is 1:5000,1:10000 and 1:20000, downhole pressure is 2.5MPa and 6.5MPa, the mixed flow velocity is between 2m/s and lOm/s. then carry on the numerical simulation for parameters which center body diameter is 51mm,52mm, 53mm, spiral line width is 2mm,4mm,6mm, spiral line height is 3mm,4mm,1 times lead and 2 times lead, spiral line is left and right. Through the analysis of the simulation results, it is found that the separation effect of 50 degree and 55 degree is better above conditions. Large central body diameter is more suitable for the low yield gas well. Spiral line width and height respectively adapt to the different velocity range. The lead multiple and guide rotation of spiral line is little influent on the separation effect. Then carry on the indoor vortex simulation experiment, to verify the computer simulation results and law. Choose six vortex current tools with different parameter combinations to simulate experiment, and measure the experimental data, then compare with numerical simulation data, to verify the computer simulation results.