×

Method and apparatus for high signal-to-noise ratio NMR well logging

  • US 7,663,363 B2
  • Filed: 06/01/2007
  • Issued: 02/16/2010
  • Est. Priority Date: 02/09/2004
  • Status: Active Grant
First Claim
Patent Images

1. A method for measuring nuclear magnetic resonance (NMR) relaxation properties of a formation with a high signal to noise ratio (SNR), the method comprising:

  • applying a magnetic field to nuclei of the formation during a polarizing interval, the magnetic field comprising a polarizing intensity having a constant magnitude resulting in a longitudinal magnetization (Mz) of the nuclei wherein the polarizing interval begins and ends before the (Mz) decreases;

    decreasing the applied magnetic field to a measurement intensity having a constant magnitude, the measurement intensity magnetic field applied to the nuclei of the formation during a measurement interval wherein a time interval for the decreasing is substantially shorter than a minimum longitudinal relaxation time of the nuclei;

    applying to the formation at least one radio frequency (RF) pulse train during the measurement interval;

    measuring an NMR signal from the formation in order to measure the NMR relaxation properties with the high SNR; and

    using a processor in order to perform at least one of the following tasks;

    store the NMR signal, analyze the NMR signal, use the NMR signal for equipment operation, and present the NMR signal to a user.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×