Horizontal oil–water two-phase flow measurement with information fusion of conductance ring sensor and cone meter

Abstract

Oil–water two-phase flow is a commonly seen flow phenomenon in petroleum and chemical industries. Online measurement of oil–water two-phase flow is a difficult problem due to the rheological complexity of its flow structure. This work presents a method of solving this measurement problem by combining a conductance-ring sensor and a cone meter to measure phase fraction, overall and individual flow rate of oil–water two-phase flow. This proposed method is based on the idea of information fusion between the conductance-ring sensor and the cone meter. Experiments were conducted on a multiphase flow loop, with the flow rate of water and oil ranges 3.9m3/h–10.2m3/h and 0.7m3/h–7.3m3/h, respectively. Phase fraction estimations with different correlations of the conductance-ring sensor calibrated under different typical phase distribution are fused at data level to deliver an estimation on volumetric phase fraction of water with an average of relative error εave=1.7%. Flow pattern is found to affect the discharge coefficient Cd of the cone meter and therefore is identified with a physically meaningful feature obtained by fusing features from the conductance-ring sensor and the cone meter. Based on the accurate flow pattern identification, the overall flow rate of oil–water two-phase flow is estimated with an associate error εave=1.6%, and the error of both the individual flow rate of water phase and oil phase is εave=2.8%. This work provides a solution of how to combine the information from heterogeneous sensors for two-phase flow measurement, and can be extended to gas–liquid two-phase flow and also in vertical flows.