Ultrasonic multiple-Backscattering Sensor for Monitoring of water-in-Crude Oil emulsions: Temperature Effect

This work deals with the development of an ultrasonic backscattering sensor for the monitoring of water-in-oil emulsion. The sensor consists of a 3.5-MHz ultrasonic transducer, working in pulse-echo mode, and an array of cylindrical obstacles located in the near field. Information from the backscattering signals was extracted by two processing methods: cross-correlation and wave energy. It was studied the sensitivity of the sensor and the time stability of the emulsions at three temperatures and volume water concentration from 0% to 50%. Cross-correlation and wave energy showed dependence on concentration. However, the wave energy showed little dependence on temperature. For water content monitoring, it was observed a measurement feasibility for concentrations below 20% with the cross-correlation methods and over all the measured range of water concentrations with the wave energy methods. On the other hand, the sensor allows the measurement of the propagation velocity in the emulsion with good accuracy and in a practical way.