Development of a multiphase composition measurement method by using capacitive sensor array

Abstract

Multiphase flow, a flow of two or more liquid/gas components, is present in many industries. One of the challenges is to measure accurately the volumetric/mass ratio of each component against the total volume/mass. In the oil and gas industry, this kind of measurement is performed on a regular basis. Since the early 1980s, many methods have been proposed for multiphase flow measurement and some are commercially available today. However, these sensors often depend on a separator to isolate each phase, or use a homogenizer/mixer to achieve consistent solutions, or employ Gamma- Ray radiation provided by a nuclear source. The approach used in this research is to combine a sensor with an integrated cyclonic stratifier that transforms diverse flow regimes of multiphase flow into a channel flow regime. The sensor employs a relatively simple capacitive sensor array and allows for accurate measurements of phase fractions in real time. The system is also capable of compensating for drift in parameters such as permittivity, often caused by a changed chemical composition, e.g. the level of sulphur in the oil, the salinity of water, or due to variable temperature.