Measurement Of The Interface Characteristics In Stratified Oil-water Two-Phase Flows

Oil-water two-phase flow widely exists in multi-phase flow system of oil well.With the exploitation amount of horizontal well increasing,horizontal oil-water twophase flow phenomena are widely encountered in petroleum production process.There are complex concentration and velocity distributions in oil-water two-phase flow,which put forward great challenges for monitoring the production profile of horizontal well.Predicting the parameter of two-phase flow through fluid physical model is another approach for dynamic monitoring of complex two-phase flow.The investigation of interface characteristics in oil-water stratified flow became the key factor for improving the prediction accuracy of the physical models.In order to investigate the interface characteristics of the horizontal oil-water stratified flow,in this study we propose a parallel-wire array conductivity probe and its measurement system.Then,the horizontal oil-water two-phase flow experiment is conducted to obtain the responses of the parallel-wire array conductivity probe.The 3D reconstruction of the oil-water interface is achieved using the probe responses.Based on the reconstructed oil-water interface,we analyzed the interfacial properties of evolution,curve and wavy for different flow patterns.The two-fluid model is modified based on the interfacial properties,and the result indicate that the modified two-fluid mode has a better performance in the pressure drop prediction.Finally,a detrended partial cross-correlation analysis(DPCCA)method is utilized to investigate the oilwater interfacial wave stability and the entrained droplets characteristics of the horizontal oil-water two-phase flow.We obtain the innovative achievements as follows:1.We design a novel measurement system of parallel-wire array conductivity probe.The system can measure the oil-water interfacial characteristics at different locations in the pipe cross section.Through reconstructing the 3D oil-water interface,the complicate dynamic characteristics of the interface is effectively uncovered.2.The standard two-fluid flow is modified on the basis of the measured oil-water interfacial characteristics.The modification of the two-fluid model improves the pressure drop prediction accuracy.3.The DPCCA is utilized for the first time to analyze the multi-scale cross-correlations of the horizontal oil-water two-phase flow structures.The results indicate that the DPCCA cross-correlation coefficient can effective uncover the oil-water interfacial wave stability and the entrained droplets characteristics of horizontal oilwater two-phase flow.