Cross correlation velocity of oil-water two-phase flow by a Dual-plane Electrical Resistance Tomography system

Oil-water two-phase flow is commonly encountered in industrial processes of petroleum and chemical engineering. The process parameters, such as velocity and phase concentration of the mixture are of great importance in both scientific and engineering field. Cross correlation technique is one of the methods of calculating the flow velocity by deriving the transit time of the fluid flowing through a pair of parallel mounted sensors on the target pipelines. The physical meaning of the cross correlation velocity is still an open discussion in the field of multi-phase flow measurement. In this research, a Dual-plane Electrical Resistance Tomography (ERT) is adopted to cross correlate the sensing data from two electrode planes. A method of dynamically seeking suitable signal segment for cross-correlating measured signals from two-phase flow is proposed. The results show that the cross correlation velocity is a structural velocity within two-phase flow, and the relationship of cross correlation velocity and mixture velocity is affected by the water flowrate within the two-phase flow.