Method and system for detecting dead point of suspended point of polished rod in pumping well

Abstract

The invention discloses a method and a system for detecting the suspension and dead points of polished rods in pumping wells. The detection method includes: based on the synchronous dynamometer diagram, collecting the electric power diagram X(i) of the pumping well for one stroke cycle; setting the time series x(i) based on the electric power diagram X(i), and calculating y according to the mean value filter formula '(i), obtain the corrected time series based on the corrected time series to obtain the filtered output signal y(i); obtain the variance Qd(i) of the time series x(i) and the filtered output signal y(i) ); Obtain the dead point of the suspension point based on the variance Qd(i). Its advantages are: it can realize the online correction of the electric power diagram and the indicator diagram of the pumping well, and the real-time detection of the dead point of the suspension point is helpful to judge whether the displacement sensor of the indicator diagram is normal, and improves the monitoring ability of the working condition of the pumping well. The safety is high, and the practical application is easy to install, operate and maintain.

Description

technical field [0001] The invention relates to the field of working condition monitoring and liquid quantity measurement of oil pumping unit wells, and more particularly, to a method and a system for detecting the dead center of a polished rod suspension point of a pumping unit well. Background technique [0002] In order to improve the production efficiency and management level of oil and gas production enterprises, dynamometer diagrams are commonly used in oil wells in various oil fields to measure oil well fluid volume online and monitor oil well conditions. The dynamometer monitoring, diagnosis and measurement system consists of three parts: perception layer, transmission layer and application layer. Collect data such as dynamometer diagram of pumping unit and information on opening and shutting well through on-site sensor equipment, and transmit the data to the data processing unit RTU. RTU transmits the data to the server through wireless or wired network, and the ser...

AI Technical Summary

Problems solved by technology

For the displacement detection method, the most commonly used method is to measure the position indirectly by measuring the acceleration, which can realize the wireless test of the displacement, simplify the test procedure, improve the reliability of the dynamometer measuring instrument and the accuracy of the displacement test data, However, there is a problem in the acceleration sensor measuring the displacement that the dead point drifts due to the acceleration oscillation of the dead point, which affects the displacement detection accuracy; for the dead point switch method, the dead point switch installed at the suspension point is easily damaged by collision

In summary, the current dead point detection method for the suspension point of pumping wells has problems such as high investment and maintenance costs, poor implementability, and unguaranteed accuracy.

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