Patent ID: 6882147
Filing Date: 2005-04-19
Classification: G01N,G01R,G01V

Abstract:
1. A method of identifying a presence of a first fluid having a first transverse nuclear magnetic spin relaxation time T 1 in a mixture of earth formation fluids with a second fluid having a second transverse nuclear magnetic spin relaxation time T 2 ′ greater than said first transverse relaxation time, the method comprising: (a) producing a static magnetic field in said mixture of said earth formation fluids; (b) applying a pulse sequence having pulses to said mixture where A 1 is a first excitation pulse, τ is a Carr-Purcell time, B 1 is a first refocusing pulse, A 2 is forced inversion pulse, A 3 is a second excitation pulse, and TW is a wait time wherein a resulting signal from said second fluid in said earth formation is substantially zero and (c) determining said presence by analyzing signals after said second excitation pulse.