deep well pump efficiency refers to the ratio of the actual pumping well liquid production and deep well pump displacement theory. Actual production in order to separate the amount of oil as the basis, the theoretical displacement of the deep well pump is the stroke multiplied by the number of strokes and then multiplied by the area of the plunger. Is an important indicator to measure the working condition of deep well pump. In the actual production there are factors affecting deep well pump efficiency, such as leakage, gas, filling and pump stroke loss and other factors, the actual output is less than the theoretical displacement of oil pump, the pump efficiency is generally less than 1, when the oil pumping with gushing when pump efficiency may be greater than l at this time the pump efficiency of deep well pump can not represent the actual working efficiency, and can only show the production condition of oil well. deep well pump efficiency reached 70% of the high efficiency, generally only 30% to 50%, or even lower, the deeper the pump, the lower the level of moving and the lower the degree of sinking, the pump efficiency is relatively lower.
There are two main factors affecting the pump efficiency of deep well pump:
1. Stroke loss. The variation of the load of sucker rod and tubing to generate elastic deformation, displacement and piston rod to cause no displacement or displacement rod began because of the rod bending caused by the stroke of the piston plunger displacement caused by no less than rod stroke, called stroke loss.
2. Nvalid stroke. Although plunger displacement, this part of stroke but did not produce pumping effect, mainly in the following 4 aspects:
1). Leakage effects on deep well pump efficiency: the cause is mainly manifested in the clearance between the plunger and pump barrel pump leakage is too large is not reasonable, pump parts wear or corrosion formation leakage deep, and leakage of tubing and other factors reduce the pump efficiency.
2). Failure of the valve action of deep well pump efficiency effect on magnetic or foreign bodies and deviation effect of valve normal action factors reduce the pump efficiency.
3). Filling dissatisfaction with the deep well pump effect: the sinking of the low, slow down or well fluid viscosity is too high, the inlet channel resistance is too large to cause deep well pump suction filling process, reduce the pump efficiency.
4). The effect of gas influence on the pump efficiency: smoke free gas suction process of the pump barrel, when the plunger from bottom upward, gas expansion pressure, the pump cylinder decreased slowly, until the pump cylinder pressure is lower than the fixed valve to open the sinking pressure, began to enter the oil. When the piston from TDC downward, by compressed gas pump, cylinder pressure rise slowly, the traveling valve can be opened until the pump pressure is higher than the piston above fluid column pressure, discharge oil, these phenomena directly affect the pump efficiency. The more the free gas in the pump barrel or the larger the clearance volume of the deep well pump, the more serious the influence of the gas.
Improving the pump efficiency of deep well pump can improve the pump efficiency and reduce the actual output. There are three main aspects:
1. Starting from the reservoir, to ensure that the oil reservoir has sufficient supply capacity, so that the production capacity of the deep well pump and reservoir fluid supply capacity to adapt is to ensure the premise of high pump efficiency.
2. To take measures to make the pumping system in the case of constant displacement of theory to improve the system capacity, so as to improve the actual production, and thus improve the efficiency of deep well pump. General measures are: choose reasonable pumping parameters (pump diameter, stroke, number), increasing the piston stroke; to determine the reasonable submergence degree and improve the structure of the pump to reduce flow resistance, improve the pump with coefficient; improve the wear and corrosion resistance, reduce the pump leakage; tubing anchor reduce stroke loss; rational use of energy of gas control reasonable casing pressure; the use of gas to reduce the influence of the gas anchor.
3. In two aspects in front of all reasonable, small pumping parameters reduce the theoretical displacement of deep well pump can improve the pump efficiency.
