| US 7,511,488 B2 | ||
| Viscosity determination from logarithmic mean ratio of relaxation times | ||
| Pedro Antonio Romero, Buenos Aires (Argentina); Benito Eduardo Saavedra, Buenos Aires (Argentina); Hyung Tae Kwak, Spring, Tex. (US); and Gabor Hursan, The Woodlands, Tex. (US) | ||
| Assigned to Baker Hughes Incorporated, Houston, Tex. (US) | ||
| Filed on May 01, 2007, as Appl. No. 11/742,768. | ||
| Prior Publication US 2008/0272773 A1, Nov. 06, 2008 | ||
| Int. Cl. G01V 3/00 (2006.01) | ||
| U.S. Cl. 324—303 | 18 Claims |
| 1. A method for determining viscosity, η, of a fluid downhole, the method comprising:
performing a nuclear magnetic resonance (NMR) survey of the fluid;
determining a longitudinal relaxation time, T1, and an apparent transverse relaxation time, T2app, for the fluid wherein obtaining a magnetization decay of multiple NMR echo trains provides for determining T1 and T2app;
forming a ratio R of T1/T2app for the fluid;
determining the viscosity, η, according to the ratio, R; and
providing the viscosity to a user as a result.
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