Patent ID: 6232778
Filing Date: 2001-05-15
Classification: G01N,G01V

Abstract:
A method of determining the amount of bound fluid in an earth formation utilizing a nuclear magnetic resonance (NMR) tool that is placed in a borehole in the formation and which produces a static magnetic field and an oscillating magnetic field according to a pulse sequence, and measures induced magnetic signals, the method comprising:applying the static magnetic field from the NMR tool to a volume of the formation;applying the oscillating magnetic field to the volume of the formation for a plurality of pulse sequences, each pulse sequence being preceded by a shortened wait time, without an extensive wait time for full polarization, so that the static magnetic field only partially polarizes the volume of formation and induces signals only from bound fluid in the volume of formation;measuring the induced signals; anddetermining the amplitude of the induced signals, the amplitude being representative of the amount of bound fluid in the formation.