A Modified Adaptive Cross Correlation Method for Flow Rate Measurement of High-Water-Cut Oil-Water Flow Using Planar Flowmeter

This article proposed a modified adaptive (MA) cross correlation method to measure the flow rate of high-water-cut oil-water two-phase flow. It asynchronously commences the acquisitions of the upstream and downstream signals for cross correlation according to the flow rate, enhancing the degree of correlation between them, thus a higher measurement accuracy of transition time can be obtained. By limiting the searching scope of the correlogram's peak value in a transition time-related observation window, the calculation process is kept steady and divergence due to the outliers is effectively avoided. A planar flowmeter is adopted for high-water-cut flow rate measurement, and the advantages in axial resolution and sensitivity are analyzed. Experiments are conducted in 90% water cut oil-water flow in a practical vertical well. Results show that compared to the conventional (C) one, the MA method is capable of fast and reliable capture of the transition time from the upstream to the downstream sensors in a much wider flow rate range, with much lower deviation and a higher degree of correlation. Finally, the flow rates and their uncertainties are calculated from the measured transition time to validate the measurement stability.