The Challenges of Wide Ranging Viscosity Fluids on Liquid Ultrasonic Flowmeters

Wide ranging viscosities in ultrasonic flow measurement for liquids is a common pipeline scenario. With ever maturing oil fields and the growth in oilsands production, the trend appears to be towards the higher end viscosities and/or novel approaches towards reducing the viscosities for transportation such as heating. The variable viscosities of the fluids provide some unique challenges to ultrasonic flowmeters not only in terms of flow profile modeling, but also in acoustic signal propagation and application to elevated temperature fluids which likewise affect the accuracy or performance of the measurement. The flow profile interrogation techniques will be discussed with an emphasis on a distributed chord model together with the use of a waveguide technology that minimizes acoustic and fluid temperature effects. A combination of R&D, calibration and field testing data will both demonstrate these challenges as well as show the increased performance that results from the application of these approaches.