A method for obtaining a parameter of interest related to an earth
formation, the method including: obtaining nuclear magnetic resonance
(NMR) data from an NMR tool investigating the earth formation with a
plurality of pulse sequences of radio frequency energy, each pulse
sequence having a unique frequency, a first train of pulses having a
first interecho time (TE.sub.1) and a second train of pulses having a
second interecho time (TE.sub.2) different from the first interecho time;
relating the NMR data to a partial porosity at points to establish an NMR
response model; solving the NMR response model to calculate the partial
porosity at each of the points in the earth formation; summing the
partial porosity for each of the points corresponding to each depth of
investigation to provide a pore volume; and associating each pore volume
with the corresponding depth of investigation to provide the parameter of
interest.