集流型流体电容含水率计低流速测量原理

本文详细分析了用于生产测井中测量油、水两相流含水率的集流型流体电容含水率计在低流速下的测量原理。由于低流速时内电极表面的亲油性以及轻质相的油在垂直管道中趋于中心向上流动，集流型流体电容含水率计在低流速情况下，含水率以对数的形式改变仪器的响应频度。．

The Measure Principle of Inflatable Fluid CapacitanceWatercut Meter at Low Flow Velocity.

The measure principle of inflatable fluid capacitance watercut meter applied to production logging for measuring watercut in oil/water two phases flow at low flow velocity is studied in this paper. Since the insulator layer covering the inner electrode is contaminated with oil and the oil bubbles tend to rise in the middle of a vertical pipe(when gas/liquid flow upwards in vertical pipe, the gas bubbles tend to rise in the middle of the pipe, so it should be the same for oil/water. ),it is considered that the watercut changes the watercut meter response frequency logarithmically at low flow velocity. As an isopotential body, the water changes the electric field distribution between the electrodes, which equals the inner diameter of the outer electrode. According to this measure principle, the watercut meter can distinguish water from oil with watercut ranging from 0% to 100% and the sensitivity increases with the watercut. The static and dynamic experiment results both accord with the new measure principle, which is valuable for inflatable fluid capacitance watercut meter applied to low flow rate production well.