Patent ID: 8863587

Claim:
A method for determining a first flow rate (q g ) of a gas phase and a second flow rate (q) of at least one liquid phase present in a polyphasic fluid circulating in a conduit, the method comprising: circulating the polyphasic fluid through a neck of a venturi delimited by a conduit, the polyphasic fluid forming a gas-rich core and a liquid-rich shell in the neck, measuring a pressure difference (Δp) of the fluid through the neck; measuring a property (Γ g ) representative of the relative surface occupied by the gas phase relative to a total surface over a cross-section of the neck; estimating the first flow rate (q g ) and the second flow rate (q l ) by using the measured pressure difference (Δp) and the property (Γ g ) representative of the relative surface occupied by the measured gas phase; wherein estimating the first flow rate (q g ) and the second flow rate (q l ) further comprises: (a1) calculating an amount (e d ) of the liquid phase present in the gas-rich core relative to the total amount of liquid phase in the neck depending on at least one amount (W e ′) representative of the flow of the polyphasic fluid in the neck and a first set of parameters (p 3 , p 4 ) depending on the geometry of the venturi and independent of the first flow rate (q g ) and of the second flow rate (q), (a2) calculating the first flow rate (q g ) and the second flow rate (q l ) as a function of the amount (e d ) representative of the liquid phase present in the core calculated during (a1).