| US 7,501,819 B2 | ||
| Measurement apparatus and method | ||
| Joo Tim Ong, Aberdeen (United Kingdom) | ||
| Assigned to Baker Hughes Incorporated, Houston, Tex. (US) | ||
| Filed on Sep. 23, 2005, as Appl. No. 11/233,900. | ||
| Claims priority of application No. 0421266.8 (GB), filed on Sep. 24, 2004. | ||
| Prior Publication US 2006/0071661 A1, Apr. 06, 2006 | ||
| Int. Cl. G01V 3/00 (2006.01) | ||
| U.S. Cl. 324—306 [324/322] | 30 Claims |
| 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.
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