Multiphase flow metering principles

Publisher Summary: This chapter deals with the objective of multiphase flow metering (MFM)— that is, to determine the flow rates of the individual components. If homogeneity of flow can be achieved, then three instruments are required each measuring a characteristic of the mixed fluid flow. The flow rates of each phase are then inferred from these measured parameters in different ways depending on the specific metering technology. In the first approach, the three independent flow parameters are measured, and the relationships between them and the flow rates of the respective phases are established. With the second approach, the basic parameters of phase velocities and phase hold-ups are measured. The phase velocities and the phase hold-ups are then combined together to provide the phase flow rate. For a three-phase flow, three mean velocities and three-phase cross-sections are required. By separating the phases, the need for cross-sectional hold-up measurements disappear and the three volume flows can be established by conventional single-phase metering technology. There are five basic parameters that can be measured by MFM devices: (1) density, (2) velocity, (3) momentum, (4) mass flow, and (5) elemental analysis. The methods of measurement can be reduced to three main categories of MFM techniques: (1) techniques dependent on homogenization of the flow, (2) techniques not dependent on homogenization, and (3) techniques depending on the whole flow separation and separate measurements