Patent ID: 7501819
Filing Date: 2009-03-10
Classification: G01F,G01R

Abstract:
1. A method of determining flow characteristics of a multiphase fluid along a flow path comprising: imparting a primary magnetic field on the multiphase fluid flow to align nuclei of the multiphase fluid with a direction of the primary magnetic field; imparting a radio frequency signal on the multiphase fluid flow to excite the nuclei of the multiphase fluid flow; receiving a radio frequency signal emitted by the excited nuclei of the multiphase fluid to derive a Nuclear Magnetic Resonance (NMR) signal; and alternating between a phase ratio mode comprising processing the received radio frequency signal to determine a ratio of at least one phase with respect to another phase in the multiphase fluid, and a phase flow mode comprising imparting a secondary magnetic field in a region of the fluid flow which varies in magnitude along a length of the fluid flow path to provide a variation in the magnetic field experienced by the nuclei of the multiphase fluid dependent upon their position along the flow path to determine velocity of the multiphase fluid flow.