Patent ID: 6023164
Filing Date: 2000-02-08
Classification: G01N,G01V

Abstract:
A centralized nuclear magnetic resonance (NMR) apparatus for conducting in-situ borehole measurements in a highly conductive environment comprising:a probe having a longitudinal axis and at least one magnet with a north pole and a south pole, said at least one magnet generating a static magnetic field in the borehole with magnetization direction substantially perpendicular to said longitudinal axis;a shield covering one of said north and south poles of said at least one magnet for reducing sensitivity of the probe to NMR signals from the corresponding magnetization direction;means for generating a time-variable magnetic field in a direction perpendicular to the static magnetic field;means for positioning the probe eccentrically within the borehole, such that the uncovered pole of said at least one magnet is positioned close to a sidewall of the borehole; andan antenna for receiving NMR signals from excited nuclei in the borehole.