Integrated Capacitance-Ultrasonic Sensor for Gas-Liquid-Solid Multiphase Measurements: A Proof of Concept

Abstract

Capacitance and ultrasonic sensors are used to detect solid particles in a multiphase flow mixture. In this study, it is proposed to utilize the capacitance and ultrasonic techniques in an integrated industrial device that can be used in gas-liquid-solid multiphase flow measurements for practical purposes. The key feature of the developed integrated sensor is the ability of the ultrasound sensor to detect the concentration of the solid particles while the capacitance sensor identifies the ratio between the gas and liquid phase in the total mixture. Two-dimensional finite element analysis using COMSOL© is used to design the optimum sensor configuration and to show the feasibility of the developed sensor. Experiments were performed utilizing materials that mimic a frozen multiphase flow mixture to perform static tests to determine the calibration coefficient and validate the sensor design. The need for multiphase flow measurement in the oil and gas production and petrochemical industries has been significantly increased over the last few years. Reliable measurements of the multiphase flow parameters such as void fraction, phase concentration, phase velocity and flow pattern identification are important for accurate modelling and/or in the operation of multiphase systems. Although many multiphase flow meters were recently developed, challenges in measuring multiphase flow components remain unresolved. Therefore, extensive research efforts were spent in designing accurate multiphase flow meters and several meters are currently under development worldwide. However, due to the complexity of the multiphase flow mixture and in some cases when three or more phases co-exist, it is difficult to adopt only one technique to develop a multiphase flow meter. Consequently, the integration of multiple sensors, based on several measurement techniques, found to be the optimum solution for accurate multiphase flow metering. In this study we investigated both capacitance and ultrasonic techniques for their potential use in detecting solid particles in multiphase flow mixture.