In the sub-sea segment there are three major providers for commercial multiphase flow meter. For the topside and offshore segment, there are around 15 providers for multiphase flow meter product. For sub-sea segment all available meters use a combination of technologies to perform multiphase flow measurements.
Some providers use bulk impedance measurement technology to estimate the phase fractions. Velocity measurements are addressed through Venturi and cross-correlation techniques. These meters are capable of measuring multiphase flow in both watercontinuous and oil-continuous states. This has been achieved by improving electrode configurations, implementing faster electronics and advanced signal processing algorithms.
Multiphase flow meter using microwave tomography with error < 10% is also available commercially. The claim here is capability to estimate the phase fraction accurately through tomography and address the error associated with slip velocity of liquid and gas through cross- correlation techniques. Apart from microwave techniques, these meters use a Venturi to measure the bulk velocity and also to condition the flow profile to be annular before the phase fraction measurements.
Overall, the market is converging towards measuring fractions, velocities and densities of each phase separately in order to achieve higher accuracies.