Patent ID: 8322228
Filing Date: 2012-12-04
Classification: G01F

Abstract:
1. A method of measuring a property of a multiphase fluid, the multiphase fluid including a gas phase and a liquid phase and the liquid phase comprising at least one of oil and water, travelling through a conduit, wherein the liquid phase travels substantially along an inside-wall of the conduit, the method comprising: using a mixing rule and a notional water-in-liquid ratio to estimate a speed of sound in the liquid phase; measuring a thickness of the liquid mixture using the estimated speed of sound; measuring at least one of a permittivity and a conductivity of a portion of the multiphase fluid; combining the thickness measurement with the at least one of the permittivity and the conductivity measurement to obtain a derived value for at least one of the permittivity and the conductivity of the liquid mixture; using at least one of the derived permittivity and the derived conductivity and a relationship between a single phase liquid property and a corresponding two-phase property of the liquid mixture to obtain a calculated water-to-liquid ratio of the liquid mixture; and comparing the calculated water-in-liquid ratio to the notional water-in-liquid ratio; using the comparison of the calculated water-in-liquid ratio to the notional water-in-liquid ratio to adjust the notional water-in-liquid ratio; and repeating the steps of the present method iteratively using the adjusted notional water-in-liquid ratio until the notional water-in-liquid ratio is approximately equal to the calculated water-in-liquid ratio.