Method based on parallel-wire conductivity probe for measuring water hold-up in near-horizontal oil-water two-phase flow pipes

On the basis of a quick-closing valve technology, parallel-wire conductivity probes were designed to measure water hold-up of oil-water two-phase flow in near-horizontal pipe. First, the electric-field distribution characteristics of the parallel-wire conductivity probe and its response to the change of the water layer height were calculated by using finite-element method. Then, for the oil-water stratified distribution in the near-horizontal pipe with a 5 degrees inclined angle, 20 mm inner diameter, and 1050 mm length, a measurement model for water hold-up was established. After that, a static experiment was carried out to investigate the accuracy of water-hold-up measurement. The results show that errors occur when the set water hold-up is with high values. The measurement errors were analysed based on curved oil-water interface predicted by Young-Laplace equation model, which are significantly related to the curvature of oil-water interface. It provides an effective experimental method for the measurement of water hold-up in a near-horizontal oil-water two-phase flow pipes. On the basis of this, the dynamic experiment of oil-water two-phase flow was carried out, and the slippage of oil-water two-phase flow was preliminarily revealed.