With more than a decade of experience acquired using Venturi/gamma ray multiphase flowmeters (MPFMs), further gains in measurement quality and operational robustness have been achieved. This paper will illustrate how enhancements in fraction measurements using multienergy gamma ray attenuation and a more comprehensive analysis of the gamma ray spectrum have been developed and implemented to provide greater measurement accuracy and stability, leading to enhanced performances in multiphase-flow measurements.
Introduction
Increasing industry interest in MPFMs has led to numerous developments in the search for the technology (or, more generally, combination of technologies) most capable of providing multiphase-flow measurements in a wide range of conditions with high levels of accuracy and moderate sensitivity to input parameters and their variations. Several manufacturers have revised their operating principles over the past few years. These revisions include replacing either one or several core-measurement blocks; providing optional added measurements to improve accuracy; or completely changing operating principles, either to replace existing meters or to target specific markets.
Two core technologies have proved very reliable in the field of multiphase metering: Venturi meters for flow velocities and gamma ray measurements to determine flowing fractions.