Patent ID: 8855263

Claim:
A method for measuring a composition of a multiphase fluid, the method comprising: radiating a photon beam through the multiphase fluid; measuring radiation absorption by the multiphase fluid for at least three energy levels to obtain measured radiation absorption data; providing the measured radiation absorption data to processing unit configured to calculate the composition of the multiphase fluid using the measured radiation absorption data, wherein an effect of an injected fluid on the absorption of the photon beam is taken into account during calculation of the composition of the multiphase fluid; setting up a matrix equation scheme relating a linear attenuation coefficient for the multiphase fluid to phase fractions of components in the multiphase fluid and to a volume fraction of the injected fluid, wherein the matrix equation scheme uses at least one the following equations: μ oil — prod α oil +μ gas — prod α gas +(μ water — prod (1 −w )+μ water — inj w )α water =μ mix ; μ oil — prod α oil +(μ gas — prod (1 −w )+μ gas — inj w )α gas +μ water — prod α water =μ mix ; and (μ oil — prod (1 −w )+μ oil — inj w )α oil +μ gas — prod α gas +μ water — prod α water =μ mix , wherein the subscripts mix, water_prod, water_inj, gas_prod, gas_inj, oil_prod, and oil_inj refer to multiphase fluid, water from the aquifer, injected water, produced natural gas, injected natural gas, produced oil, and injected oil-solvent mixture, respectively, μx is the linear attenuation coefficient of the x-component in the multiphase fluid, αx is the phase fraction of the x-component in the multiphase fluid, and w is the volume fraction of the injected fluid in a produced fluid, wherein the injected fluid is one selected from a group consisting of injected water, injected natural gas, and injected oil-solvent mixture, and the produced fluid is one selected from a group consisting of water, gas, and oil; and calculating the composition of the multiphase fluid with the processing unit using the measured radiation absorption data and the matrix equation scheme.