A visual measurement method for oilfield downhole water holdup

Abstract

The invention relates to a visualization measurement method for the specific retention under an oil field well. The visualization measurement method includes the steps of distributing an ERT sensor array at the position of the oil-water mixed cross section under the well to be measured, measuring a voltage across adjacent electrodes in the ERT sensor array, then obtaining an under-well oil-water distribution real-time image according to the ERT image rebuilt algorithm, and finally calculating the specific retention of the layer according to the image. According to the visualization measurement method, the electrical resistance tomography is adopted for achieving visualization measurement on the specific retention under the oil field well, influences of oil-water two-phase flow flow-type changes on the measurement accuracy are eliminated, the measurement accuracy of the specific retention of an oil-water mixture is greatly improved, and the visualization measurement method is particularly suitable for measurement on the specific retention under the high-water-content oil field well.

Description

technical field [0001] The invention relates to an electric resistance tomography (ERT) technology-based method for visually measuring oilfield water cut, which belongs to the field of measurement technology. Background technique [0002] The fluids produced in petroleum production have different water cut ratios. For oil fields that have entered the medium and high water cut development period, in order to reduce water and increase oil production, and rationally arrange the recovery of different oil layers, it is necessary to accurately measure the water content of different layers in the downhole. water holding rate. [0003] Common water holdup measuring instruments are as follows: [0004] (1) Capacitive water holdup measuring instrument, this measuring instrument is only suitable for measuring oil wells with low water holdup. , High water cut oil well; [0005] (2) Microwave water holdup measuring instrument, its principle is to use the resonance state of high-freque...

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Problems solved by technology

[0004] (1) Capacitive water holdup measuring instrument, this measuring instrument is only suitable for measuring oil wells with low water holdup. , High water cut oil well;

[0005] (2) Microwave water holdup measuring instrument, its principle is to use the resonance state of high-frequency electromagnetic waves to measure the moisture in crude oil, but it is affected by parameters such as oil film, sand production, wax deposition, heavy oil, and slippage speed. Poor repeatability, stability, consistency and standardization, making it difficult to popularize and apply;

[0008] The above-mentioned water holdup measuring instrument can only measure the average water holdup of a single point or measurement space, while the oil-water mixed water holdup measurement belongs to the measurement of gas-liquid two-phase flow, and the change of flow pattern will affect the measurement accuracy. Therefore, the existing water holdup None of the measuring instruments can guarantee the measurement accuracy of oil-water mixed water holdup

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