| 摘要 |
A method and apparatus are described using nuclear magnetic resonance (NMR) measurements for obtaining information relating to properties of geologic structures in highly conductive borehole environments. A centralized NMR logging probe is provided with a sleeve having a semi-circular RF shield that blocks signals from one side of the probe and with elements that press the uncovered side of the probe to the sidewall of the borehole. In highly conductive boreholes, the eccentrically-positioned modified probe results in increased signal-to-noise ratios and savings in peak power and energy compared with the use of standard centralized tools. The modified probe further suppresses unwanted NMR signals.
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