The Hydraulic Analysis And Experimental Research Of The Oil Well Pump Of Directional Well

Recently, with the deepening of the oil drilling, the influence of the complexity of geological factors, together with the increase of the directional well, the low pump efficiency of directional well is always the problem to be solved in the oil industry. In this paper, based on the in-depth analysis of the factors that influence the pump efficiency, it is found that the lower pump efficiency is largely because this pump isn't suitable for directional well. The pump is in a inclined state, and this makes the amount of leakage increases in the process of pump'normal production, which causes the low pump efficiency. The increase of leakage is mainly reflected in two aspects: on the one hand, it is the leakage of the annulus between pump cylinder and plunger; on the other hand, it is the leakage of fixed valve. In order to identify the leakage, the experimental apparatus that measure the leakage of the annulus between pump cylinder and plunger was built, together with the apparatus of pump efficiency of different inclination angles; simultaneously, in order to identify the submergence depth, pump's local resistance experiment was included in the pump efficiency experiment. With three experimental apparatuses established ourselves, two kinds of pump (ordinary pump and efficient pump) were tested, and the corresponding results were obtained.In the experiment of measuring leakage volume, carves of leakage of annulus between cylinder and plunger changed with pressure of two kinds of pumps of different inclination angles and different temperature are obtained, and the main reasons that cause the different leakage between two kinds of pump are analyzed. The results show soft sealing plunger is more suitable for directional well production in structure and material. Combined with generally accepted cylinder and plunger Tapered theory model, the theoretical formulas of annular leakage volume of different conditions are summarized. And with the help of experimental data, formulas of annular leakage that is suitable for directional well production are found.In the pump's local resistance experiment, the relationship of flow with pressure drop of fluids of different viscosity in different inclination angles flow over fixed valve is obtained, and the relationship curves are also gained. In the pump efficiency experiment of different inclination angles, the curves of pump efficiency of two kinds of pumps of different angles and different strokes are gained. The critical angle that the pump efficiency begins to drop of directional well is discovered. The influence of inclination angles smaller or bigger than the critical angle on pump's efficiency is analyzed, and the high efficient pump that suits to directional well is optimized. Through the comparison of total leakage and annular leakage, it is found that the total leakage mainly depends on the fixed valve's leakage.This paper mainly adopts the method of combining theoretical analysis and indoor experiments, and studies the experimental schemes of actual situations. The indoor experiment apparatus was designed and built in the Special Laboratory of Northeast Petroleum University, and experiment data were obtained from the indoor experiments, which provide evidence for field of the selection of oil well pump.