Dual-modality probe for characterization of heterogeneous mixtures

This paper presents a laboratory feasibility study aiming at the development of a dual modality sensor for development within an oil and gas extraction plant to measure the composition of heterogeneous mixtures. The technology of manufacturing the sensor is briefly described and the preliminary measurements, conducted for mixtures of vegetable oil and saline water, using two modalities: ultrasound and electrical, are presented. The experimental results obtained from ultrasonic measurements are compared with theoretical predictions. Finally, conclusions and recommendations for future work are presented.

I. Introduction

The aim of the presented study is to develop a reliable dual modality sensing technique to be deployed in the hostile environment of an oil and gas extraction plant, particularly within primary separation systems (both top-side and subsea) or, potentially, within the down-hole environment. Here, the heterogeneous mixtures consist of at least four components: crude oil, formation water, gas, and solid particulates. Typical operating conditions of such installations are characterized by high temperature reaching in excess of 150 °C pressure in excess of 150 bar, and the presence of highly aggressive chemical compounds. From the above, it is clear that any possible sensor design must meet at least two criteria: to survive the high operating pressure and temperatures and to ensure the chemical stability of the components exposed to process media.