Patent ID: 6445180
Filing Date: 2002-09-03
Classification: G01N,G01V

Abstract:
A side-looking nuclear magnetic resonance (NMR) sensing apparatus for operating in a bore hole to sense NMR signals emanating from a region of interest in a formation adjacent the bore hole, the tool comprising:(a) a magnet for inducing a static magnetic field in the region of interest; (b) a transmitting antenna assembly for inducing a radio frequency (RF) magnetic field in a first region including the region of interest; (c) a receiving antenna assembly for receiving signals from a second region including the region of interest; and (d) a spoiler antenna assembly for spoiling the RF magnetic field so that the resultant RF field is forcefully mismatched to the static magnetic field in a portion of said second region outside the region of interest in order to reduce contributions to the sensed NMR signal therefrom, said portion including a portion of the bore hole.