Research On Hydraulics Of Oil Pump Based On Fluent

The oil pump is one of the key components in a rod pumping system. With the majority of oil fields in our country entering the middle and later stages, the oil reservoir environment is becoming more complicated, the depth of plunger is increasing and the benefit of oil fields is declining day and day, all of above-mentioned reasons make the stress condition of sucker rod more complex and the working environment of oil pump worse. The leakage and frictional force between the plunger and pump cylinder have direct influence on the production status of sucker rod pumping system. At present, the research on the valve of the oil pump can not simulate the real working conditions of the underground oil well pump.。In this paper, in view of the above situation, considering the factors that affect the working characteristics of the pump, mainly research include the following aspects:Firstly, the relative factors affecting the friction between the plunger and pump cylinder are analyzed, such as the eccentric rate, clearance level, pump diameter, velocity of plunger, pressure difference of plunger, etc. By using the Gambit software, the three-dimensional simulation model of the clearance between the plunger and pump cylinder is established. By setting import and export pressure, fluid properties and the velocity of plunger in FLUENT software, the transient simulation model of the clearance between the plunger and pump cylinder is established.Secondly, the leakage and frictional force of Newton fluid and power-law fluid in the gap of the plunger and pump cylinder concentric and eccentric are calculated. According to the simulation results, the expressions of leakage and frictional force are obtained, and the sensitivity analysis model is established.Then considering the motion characteristics of the ground pumping unit, the piston motion model is established based on the motion law of the suspension point; In the case of the motion law of piston, in connection with the whole process of the fluid intake pump, the two-dimensional model of the oil pump is established, then the grid division and boundary conditions are specified. Combined with the dynamic grid technology and UDF programming, the numerical simulation is developed based on the application of computational fluid dynamics software Fluent. The synchronous solution of plunger motion and flow field calculation is realized.Finally, The fluid velocity distribution at different time is obtained. And the effect of valve port opening degree, sinking pressure, gas-liquid ratio, oil viscosity and plunger speed on fluid pump full extent is got. The results of numerical simulation provide a reference for the future research of the oil pump.