Volume Flow Rate Measurement in Vertical Oil-in-Water Pipe Flow Using Electrical Impedance Tomography and a Local Probe

This paper presents the use of a high performance dual-plane electrical impedance tomography (EIT) system and a local dual-sensor conductance probe to measure the vertical upward co-current oil-in-water pipe flows. Experiments were carried on a flow loop with a transparent 2.5 m long, 80 mm inner diameter test section using kerosene and tap water. The flow conditions were predominantly of the dispersed type with the non-slip oil volume fraction of 9.1%, 16.7% and 23.1% respectively, and with two groups of different mixture velocities. A sensitivity coefficient back-projection (SBP) algorithm was adopted to reconstruct the flow distributions from the EIT measurement data, and then the oil in-situ volume fraction was calculated based on Maxwell relationship with temperature compensation. The oil velocity distribution was obtained using a pixel to pixel cross correlation method. A local intrusive conductance probe was adopted to supply a reference measurement of oil volume fraction and velocity profiles. The oil volume fraction and velocity distributions from the two techniques were compared, and good agreement was found. A further calculation of the water velocity distributions and flowrates was implemented through the drift flux approach, and the results were analysed and discussed.