In one embodiment of the present invention, a method of measuring the
molecular displacement of a fluid is disclosed comprising: (a) applying a
strong magnetic field gradient to the fluid; (b) applying a sequence of
oscillating magnetic field pulses to the fluid wherein the sequence
includes a first portion followed by a second portion, wherein the first
portion spatially modulates the magnetization state of the fluid and the
second portion monitors the evolution of the modulation; (c) detecting
magnetic resonance signals from the fluid; and (d) analyzing the detected
signals to determine the molecular displacement of the fluid. This method
may be used to determine the diffusion of the fluid or the restricted
diffusion of the fluid through the porous media if the fluid is within a
porous media (such as earth formation, bone, wood or other material). Also
disclosed is a logging tool configured to implement this methodology.
