Method and device for diagnosing working conditions of underground oil well pump

Abstract

The invention provides a method and device for diagnosing the working conditions of an underground oil well pump. The method comprises the following steps: obtaining an equation set for diagnosing the working conditions of an oil well pump according to the movement conditions of a sucker rod, and calculating the displacement relationship between the cross section of the sucker rod on each level; discretizing a ground indicator diagram to obtain the polished rod load of a pumping unit in multiple time periods as well as the polished rod displacement corresponding to the polished rod load of each time period; stepwise calculating the cross section load of the bolt-support cross section on the level closest to the oil well pump as well as the cross section displacement corresponding to the cross section load from the bolt-support cross section on the level farthest from the oil well pump to the bolt-support cross section closest to the oil well pump, and drawing the indicator diagram of the oil well pump; and comparing the indicator diagram of the oil well pump with a preset pump indicator diagram to determine the working conditions of the underground oil well pump. In the embodiment of the invention, by adopting the method, the diagnosis precision of the working conditions of the underground oil well pump is effectively improved, and the accuracy of the diagnosis result of the working conditions of the underground oil well pump is guaranteed.

Description

technical field [0001] The invention relates to the technical field of petroleum exploration, in particular to a method and a device for diagnosing the working conditions of downhole oil well pumps. Background technique [0002] At present, the fault diagnosis of oil wells is mainly carried out by using the ground polished rod dynamometer. Specifically, first use the ground polished rod dynamometer to draw the relationship curve between the polished rod load and displacement, that is, the polished rod dynamometer diagram, and then the polished rod dynamometer diagram Interpretations are made to determine failures of oil wells and equipment. [0003] Regarding the above-mentioned method of directly diagnosing the working condition of the downhole oil well pump by using the polished rod dynamic instrument on the ground, in order to improve the accuracy of diagnosing the working condition of the well pump, there are mainly the following two aspects: [0004] 1) Continuously im...

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Problems solved by technology

[0009] However, in view of the limitations of the computer development level, and the limitations of factors such as the poor convergence of the Fourier transform solution method, it is difficult to popularize and apply this method.

[0010] For the above-mentioned problem of how to simply and efficiently improve the diagnostic accuracy of the working conditions of the oil well pump, no effective solution has been proposed so far

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