Design and testing of a thick-film dual-modality sensor for composition measurements in heterogeneous mixtures

Abstract

The current paper focuses on design and laboratory evaluation of a dual-modality sensor, developed for the needs of oil and gas extraction industry to measure the composition of heterogeneous mixtures in harsh conditions. The sensor combines ultrasonic and electrical measurement techniques, which are non-destructive, rapid and can potentially provide an on-line industrial measurement. Such a 'dual-modality' measurement could potentially be reliable in a wider range of process conditions. A distinct feature of the sensors presented here is their construction, which makes use of the thick-film technology, enabling the construction of multi-layered structures of both conductive and non-conductive layers, some of which may exhibit piezoelectric properties for ultrasonic measurement purposes. These are later fired on a ceramic substrate to provide rugged sensors, capable of working in aggressive industrial environments. Laboratory experiments to investigate the feasibility of the dual-modality sensors were conducted and some comparisons with the theoretical predictions are presented.

Composition measurements of crude oil and process water emulsions using thick-film ultrasonic transducers

“…It is believed that the size and the material characteristics of such sensors may be beneficial for constructing slim-line and robust probes, or sensors which can be potentially easily embedded and distributed within the process environment-in particular, within the oil and gas extraction plant, which was envisaged as the main application area. The design philosophy behind these sensors and the detailed design and fabrication procedures were already reported in [1] and will not be repeated here.…”

“…In brief, the fabrication of thick-film sensors involves successive screen-printing and high temperature firing of thick-film pastes [1]. These form a multilayer sandwich of two metallic electrodes (each around 10 m thick) with piezo-ceramic material (about 50 m thick) placed in between the electrodes, deposited on an alumina substrate.…”

“…[1], except that the LCR meter for electrical measurements was not used, and there was no need to use surfactants to stabilise the mixtures. A pair of ultrasonic sensors was incorporated into a small measurement "cell" comprising two identical transducers (one "sender", one "receiver") facing one another and located at a distance of 12 mm.…”

“…A brief history of the applications and theoretical developments of ultrasonics is given in Ref. [1]. In the context of ultrasonic composition measurements in oil-water mixtures, it is perhaps worth mentioning Tavlarides and coworkers [8,9], who conducted investigations into monitoring the dispersed volume fraction, in liquid-liquid column extractors and stirred vessels and developed a modified time-average model for the volume fraction calculations.…”

“…In the context of ultrasonic composition measurements in oil-water mixtures, it is perhaps worth mentioning Tavlarides and coworkers [8,9], who conducted investigations into monitoring the dispersed volume fraction, in liquid-liquid column extractors and stirred vessels and developed a modified time-average model for the volume fraction calculations. 1 Chanamai et al [10] investigated the influence of temperature on the ultrasonic properties of oil-in-water emulsions. Nounah et al [11] developed a lowfrequency, near-field method for characterisation of mixtures of non-miscible liquids.…”