Patent ID: 6898541

Claim:
A method for determining component flow rates of a multiphase fluid in a conduit, the fluid consisting of at least three known components, the fluid having a pressure and temperature at each location of the fluid, the method comprising the steps of: a) measuring at each of two different positions along the conduit at least four mixture quantities; b) providing speed of sound values for each of the components at the pressures and temperatures at which the four different mixture quantities are measured; c) providing a trial value for each of either the component flow rates or phase fractions of the fluid; d) using a predetermined model to calculate values for the measured mixture quantities based on the speed of sound values and the trial values for each of either the component flow rates or the phase fractions; e) using a predetermined error function to determine an error value based on differences between the measured mixture quantities and the calculated values for the measured mixture quantities; f) determining whether the calculated values are acceptable based on the error value; and g) if the calculated values are not acceptable, using a predetermined optimizing algorithm to provide a new trial value for each of either the component flow rates or the phase fractions and repeating steps d through f.