The Optimization Design Of Plunger Gas Lift Sealing Structure And Its Flow Characteristics Analysis Of Clearance Flowing

Gas well production will be accompanied with load-up,which will affect the normal production of gas Wells.A variety of drainage gas recovery is adopted in the field to discharge the residual fluid.The plunger gas lift is a kind of drainage gas recovery,which is widely used because of its simple equipment with low investment.However,due to the influence of its own structure,the plunger tool has a large amount of leakage during the lifting process,which makes it has low efficiency when lifting.In this paper,Variable radial displacement gas production plunger is designed from the point of view of the serious leakage of the plunger.The contents of the plunger study are as follows:(1)After investigating a large number of plunger literatures and patents,then summarizing advantages and disadvantages of existing plungers.Next,designing a variable-diameter self-operated drainage gas extraction plunger tool for the problem of large leakage loss of existing plungers,Tool length 460 mm,maximum diameter 56mm;(2)The movement law Development the kinetic model of the plunger in the wellbore before studying the law of motion when the plunger in the wellbore by methods of mathematic,the numerical solution method of dynamic model has been given;(3)The finite-element analysis of the plunger sealant cylinder was carried out by ANSYS WORKBENCH software.Meanwhile,material,size,thickness and hardness of the rubber cylinder were optimized,the parameters of the sealed rubber cylinder after optimization are: material fluororubber,length 60 mm,thickness 8mm,hardness 75;(4)The gap flow law is studied,and the velocity distribution and flow calculation formula of the gap flow are introduced.Using FLUENT software to do the numerically simulate the flow characteristics of the plunger gap flow,and the flow law of plunger clearance flow and the influencing factors of plunger leakage are obtained,and the plunger has a smaller leakage loss when the gap between the plunger and the tubing is 0.3 mm and the plunger pressure difference is 1.5 MPa.