Abstract:
The downward resistance of plunger mainly comes from friction drag of well fluid passing the traveling valve, friction drag of well fluid passing the central pipeline of plunger, friction drag between plunger and pump barrel as well as other aspects. However, the traditional calculation model oversimplifies downward resistance without considering plunger structure. All of resistance coefficients of model are obtained by doing experiments with water as the medium, and they are not applicable to the polymer flooding well of heavy oil reservoir. In order to define production conditions and production parameters of the polymer flooding well of heavy oil reservoir, as well as plunger structure parameters’ effects on plunger downward resistance, the sensibility experiment versus friction drag between the central pipeline of plunger and traveling valve, and between plunger pump barrel clearance versus friction drag, have been designed respectively. Then the calculation model of friction drag of various downward elements of plunger in the polymer flooding well of heavy oil reservoir will be obtained. With regard to the polymer flooding well, the results show that the rising height of valve ball basically has no influence on resistance passing the valve, the effect of friction drag of the central pipeline of plunger on downward resistance of plunger cannot be neglected, and the effect of downward resistance of pump plunger in the polymer flooding well on friction drag between plunger and pump barrel clearance is the mostsensitive. Finally, the comparison with experimental data of the oil field indicates that accuracy is higher than that of traditional model.