Application of Array Imaging Algorithm in Horizontal Well Oil–Water Two-Phase Water Holdup Measurement

Due to the effect of gravity differentiation in nonvertical wells and the asymmetry of the space around the wellbore, the fluid flow pattern in the wellborn will change greatly. The water holdup reflects the distribution of water, which lays a foundation for understanding the proportion of oil and gas. Water holdup imaging can intuitively reflect the distribution of each phase and the overall water holdup. In this article, with No. 10 industrial white oil and tap water as the working medium, the local water holdup value was measured in the oil–water two-phase by the capacitance array tool (CAT), and then, the response characteristics of the instrument were analyzed. MATLAB software is used to interpolate the local water holdup data of the array in the oil–water two-phase of the horizontal well. The interpolation algorithms used include bilinear interpolation, cubic spline interpolation, simple inverse distance weighted interpolation, and Gaussian radial basis function (GRBF) interpolation. The results show that the water holdup measured by the CAT shows a good measurement effect at low and medium flow rates. Linear and cubic splines are selected in the case of low flow rate and low water cut in the oil–water two-phase flow with stratified flow pattern. The GRBF is selected under the condition of low flow rate and high water cut. The GRBF was selected under different water cut conditions of middle and high flow rates with dispersed flow pattern.