Measurement and Recognition of Gas­Liquid Multiphase Horizontal Flow Regimes using Electrical Resistance Tomography

Nicholas P Ramskill and Mi Wang

Institute of Particle Science and Engineering, University of Leeds, UK, pm06npr@leeds.ac.uk

ABSTRACT

The flow regime not only characterises the flow conditions, it also determines the type of flow meter and measurement model that is used. In order to develop a flow meter for the accurate measurement of multiphase flows it is of the utmost importance to correctly identify the flow pattern present to enable the selection of the optimal method for metering. In order to achieve this aim the flow will be studied under a multitude of conditions. This research studied two phase flow of air and water in horizontal pipelines. Electrical resistance tomography (ERT) technology was applied for the recognition the flow regime. The main objective of the project is to produce a flow regime map by applying ERT to the horizontal two­phase flow of air and water. The flow regimes that were investigated in this study are plug and bubble flow. This present study proposes a method for recognition of the prevalent flow regime using only a fraction of this data thus rendering the analysis more efficient. By considering the zoned average conductivity of five zones along the central axis of the tomogram key features can be indentified thus enabling the recognition of the prevalent flow regime. Visualisation of the flow using the reconstructed images provides a qualitative comparison between different flow regimes. Application of the Boolean logic scheme enables a quantitative comparison of the flow patterns thus reducing the subjectivity in the identification of the prevalent flow regime.

Keywords ERT, gas­liquid flow, horizontal flow, flow regime recognition, zoned average