A METHOD AND APPARATUS FOR MULTIPHASE FLOW MEASUREMENTS IN THE PRESENCE OF PIPE-WALL DEPOSITS

摘要

A method for determining the flow rates of a fluid comprising a multi-component mixture comprising the following steps: a. The temperature and pressure of the multi-component mixture is determined b. the fractions of the multi-component mixture is determined based on at least two measured physical properties of the multi-components mixture and knowledge of the same physical property of the individual components of the multi-component mixture c. the velocity of the multi component mixture is determined d. based on the result from step a-c, the flow rate of the individual component of the fluid is determined characterized by a method for improving the accuracy of the determined flow rates where e. an electromagnetic measurement is performed f. a statistical parameter related to the electromagnetic measurement is calculated g. the said statistical parameter is compared to an empirical derived threshold value corresponding to the value of the statistical parameter when only one of the component of the multi component mixture is present h. the thickness of unwanted deposits on the pipe wall is determined i. the result from step a-d and step h is used to obtain an improved flow rate determination of the individual components of the said fluid An apparatus for performing the method is also disclosed.