Patent ID: 6897652
Filing Date: 2005-05-24
Classification: E21B,G01V

Abstract:
1. A method for determining subterranean formation flow characteristics, the steps comprising: (a) providing a borehole through said subterranean formation; (b) positioning a nuclear magnetic resonance (NMR) tool and inducing fluid flow from said formation toward said borehole; (c) generating a first radio frequency saturation pulse of time t (d) generating a first 90° radio frequency NMR tool following a predetermined time period; (e) recording a first free induction decay (FID) signal generated by said formation fluid nuclei; (f) generating a second radio frequency saturation pulse of time t (g) generating a second 90° radio frequency pulse following a predetermined time period; (h) recording a second FID signal generated by said formation fluid nuclei; and (i) deriving formation fluid flow rate from the differences in said recorded first and second FID signals.