Patent ID: 6897652

Claim:
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 1 and intensity I 1 with said NMR tool to align nuclei in formation fluid flowing toward said borehole; (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 2 and intensity I 2 , with said NMR tool after a predetermined period of time, wherein: ∫ 0 t 1 I 1 ( dt )=∫ 0 t 2 I 2 ( dt ) (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.