Method for calculating liquid output of oil pumping unit through active power difference

Abstract

The invention provides a method for calculating the liquid output of an oil pumping unit through the active power difference and relates to a flow measurement method. The area integral of the down stroke active power in an active power curve I to time is subtracted from the area integral of the down stroke active power in an active power curve II to time, and the area integral difference is obtained. The area integral difference corresponds to an actual filling degree difference of the oil pumping unit, and then the stroke frequency liquid output II corresponding to the active power curve II can be worked out according to the stroke frequency liquid output I, measured actually, of the active power curve I. Then the stroke frequency liquid outputs II corresponding to all the active power curves II are accumulated according to time, and the total daily liquid output, the total monthly liquid output and the total yearly liquid output can be worked out. According to the method, the difference method is adopted for calculation, frequent correction is not needed, and an operator just need to conduct correction after large change of the well condition happens. A correction method is simple, and the accuracy rate is high.

Description

technical field [0001] The invention relates to a flow measurement method, in particular to a method for calculating the liquid production rate of an oil pumping unit by using the active power difference. Background technique [0002] At present, there are two main methods of fluid production measurement in pumping wells: direct measurement and indirect measurement. [0003] Direct measurement is to measure the liquid production within a fixed time, mainly including flow meter measurement and storage tank measurement: [0004] Flowmeter measurement requires the laying of pipelines for every well, the installation of flowmeters, and the construction of metering rooms in the well area. The construction cost is expensive. If the oil wells are too scattered, then the small station measurement cannot be used. The flowmeters used for measurement are commonly used for target flowmeters, multiphase flowmeters and other flowmeters. Among them, the price of target flowmeters is relat...

AI Technical Summary

Problems solved by technology

In the calculation method, the effective power calculation method is difficult to calculate the friction force, which can only be judged according to experience, and there are large errors that are difficult to correct; while the effective stroke method involves some uncertain coefficients in the process of power map conversion, such as damping coefficients, etc. etc., frequent corrections are required to meet the accuracy requirements

The current oil measurement method with the power map has problems such as low test accuracy and large maintenance, and the test load module must be installed on the sucker rod, and the well must be stopped for installation, and there are problems such as high failure rate, difficult maintenance, and high price.

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