Recognition method and system for pumping unit swimming valve opening point

Abstract

The invention discloses a method and system for identifying the opening point of a pumping unit's swimming valve. The method may include: collecting a stroke cycle electric power map graph P (T) of the pumping unit; performing third-order Mallat wavelet decomposition on the electric power map graph P (T) based on wavelet transform theory, and extracting an oscillation signal; The extracted oscillation signal is used to obtain the oscillation signal of the sucker rod; when the amplitude of the oscillation signal of the sucker rod meets the effective discharge condition, the start time corresponding to the effective discharge condition is determined as the opening time of the swimming valve. The present invention has the advantages of: apply the wavelet Mallat algorithm to decompose the sucker rod oscillation signal from a cycle electric power diagram of the pumping unit, judge the oscillation amplitude satisfying the opening signal of the traveling valve to accurately capture the signal, and use the method to On-line metering and working condition monitoring of pumping wells can improve metering accuracy and fault diagnosis accuracy, and there is no need to install a dynamometer acquisition device, which reduces the workload of operation management and daily maintenance costs, and improves economic efficiency.

Description

technical field [0001] The invention relates to the field of monitoring and metering of pumping unit wells in oil fields, and more particularly relates to a method and system for identifying the opening point of a pumping unit's swimming valve. Background technique [0002] A stroke of the pumping unit refers to the process that the piston of the oil well pump moves from the top dead center to the bottom dead center, and then from the bottom dead center to the top dead center. The first process is a downstroke, and the second process is an upstroke. During the upstroke process, the sucker rod string drives the piston to move upward, and the floating valve on the piston is closed due to the pressure of the liquid column in the pipe, so that the pressure in the pump gradually decreases. At this time, the fixed valve is under the action of the pressure difference formed by the submerged pressure and the pressure in the pump. When the pressure difference is greater than its own...

AI Technical Summary

Problems solved by technology

However, the dynamometer diagram is affected by factors such as gas, wax deposition and salt deposition, and its curvature changes the most at the position of the valve opening and closing point. The floating valve opening and closing point identified by this method does not match the actual working conditions.

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