Sealing Characteristics And Experimental Study Of Gas Lift Plunger

The sealing performance of the gas lift plunger is the key factor affecting the liquid carrying effect of the plunger,so improving the sealing performance of the plunger is very important to improve the liquid carrying effect.At the same time,when the plunger lifts and drains liquid in the large inclination section,it is often close to one side of the tubing wall,so that the plunger is in an eccentric state in the tubing,leading to the liquid leakage phenomenon on the plunger,and the sealing performance is weakened.Therefore,this paper took the rotary plunger as the research object,combined with the leakage and eccentricity in the liquid carrying process of the large incline section,adopted the research method combining numerical simulation and experimental testing to carry out the optimization analysis of the rotary plunger,improve the sealing performance of the plunger,and further improve the liquid carrying effect of the plunger.In this paper,considering the working characteristics of the gas lift plunger,combined with the existing problems of leakage and eccentricity in the gas lift plunger,based on the specific plunger structure,the structural parameters that can be used to improve the sealing performance of the plunger and the structural parameters that can improve the eccentricity effect are selected for optimization analysis.Then the numerical simulation analysis shows that when the groove depth is 3.5mm,the sealing groove width is 10 mm and the number of slots is 16,the sealing performance of the rotary plunger is the best.spss data analysis software was used to sort the influence degree of parameters that may affect the anti-eccentricity performance of the plunger spiral groove,and it was concluded that the influence of the offset Angle of the chute on the anti-eccentricity performance > groove depth > groove number > groove width.Meanwhile,the optimal parameter combination of the anti-eccentricity performance was obtained by using spss data analysis: the offset Angle of the chute is 45 degrees,the depth is 6mm.The width is 7.5mm and the number is 6,and the simulation analysis of the anti-eccentricity performance of the tangential hole shows that the position of the tangential hole at the lower part of the sealing groove reduces the sealing performance of the sealing groove.At the same time,the number of tangential holes is 12 and the diameter is 3mm,while ensuring the anti-eccentricity performance of the plunger,it can also reduce the influence on the sealing performance of the plunger sealing groove.On the basis of the simulation,combined with the laboratory conditions,the sealing performance of the experimental equipment was established,through the experimental test proved that the sealing groove structure can achieve the improvement of its own sealing performance,spiral groove and tangential hole structure can improve the eccentricity problem;The optimal parameters obtained in the simulation are verified by experiment,and the experimental results are consistent with the simulation results.Then the liquid carrying efficiency of the plunger under different working conditions was tested.It was concluded that the liquid carrying efficiency of the gas lift rotary plunger gradually increased with the increase of the gas pressure at the bottom of the hole,the increase of the liquid quantity at the bottom of the hole and the increase of the well inclination Angle.Meanwhile,the liquid carrying efficiency of the rotary plunger was above 70%.