Research On The Law Of Stuck Pump For The ASP Lfooding Pumping Unit Wells

Many changes have arisen in the flow composition and flow characteristics with thedrive method changing from water flooding to ASP flooding in Daqing oilfield. Not only oil,gas and water are included, typical high-viscosity polymers and non-Newtonian fluid are alsoincluded, which makes the flowing laws more complex than the water flooding. In the processof ASP flooding producing well, the scaling of well increased rapidly, stucking pumpphenomenon between the plunger and pump barrel, generating eccentric wear of sucker rodand tubing in rod pumped wells will make a serious pull off the rod. In addition, the fluidviscosity of ASP flooding is larger than the oil wells of water flooding, which leads toincreasing of viscosity-related friction and rising of malfunction, workover operation andlifting cost. Therefore, research on stuck pumps pumping unit laws of ASP flooding hassignificant potential for pump-stuck warning, such that we can take measures to reduce thenumber of wells operating and cut down the cost.According to the basic structure of pumping wells and the motion law of pumping unit,analyze the change law of polished rod load at up and down strokes in ASP flooding, fromwhich find the main reason of pump-stuck. Based on the case that most pump-stuck arise inthe down stroke, so make detailed analysis on the load of down stroke, the stuck reason islargely due to the change of friction load by comparing. The clearance decreaseing betweenthe plunger and pump barrel leads to the friction increasing between them rapidly, when therod weight is smaller than the polished rod load of down stroke, then pump-stuck happens.Summarize the law of pump-stuck for pumping unit wells through the analysis of thepumping rod load changes.In order to verify the law of stuck pump for pumping unit wells, the field and laboratoryexperiment are carried out. The change rule of scaling rod loads is obtained through continousdatas of two scaling wells. Because of the limited field well datas, establish laboratoryexperiment to simulate the field wells. The field and laboratory experiment results coincidewith pump-stuck theory, showing the accuracy of pump-stuck theory.