Patent ID: 8701461

Claim:
A method for calibrating a multiphase flowmeter comprising the steps of: providing the multiphase flowmeter; providing a vertically placed calibration device comprising: a tube for holding a liquid multiphase sample, wherein the multiphase sample comprises at least one liquid phase and at least one gas phase, wherein the liquid phase is water; a temperature sensor; a pressure sensor; and three ultrasound transducers positioned at one or more specific locations in or around the tube, wherein the transducers comprise a bottom/transversal (BT) pair, a top/transversal (TT) pair, and a longitudinal (L T L B ) pair; trapping the multiphase liquid sample in the tube of the calibration device; allowing the trapped multiphase sample to separate into two or more component phases; measuring an ultrasound velocity (UV) in the water by using the BT pair of ultrasound transducers; measuring the UV in the gas by using the TT pair of ultrasound transducers, wherein the step of measuring the UV in the gas and in the water may be performed simultaneously; calculating an ultrasound propagation velocity for gas (UV g ) and water (UV w ); measuring the UV in the mixture (UV m ) by using the L T L B pair of ultrasound transducers, wherein the L T L B pair of ultrasound transducers are operated in a transmission mode; obtaining a gas volume by using the L T in a reflection mode and combining it with the UV g ; obtaining a water volume by using the L B in the reflection mode and combining it with the UV w ; and calibrating the multiphase flowmeter by verifying and adjusting the gas volume and the water volume with the result for the UV in the mixture.