1. A method for obtaining a parameter of interest related to an earth formation, the method comprising: 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 1 ) and a second train of pulses having a second interecho time (TE 2 ) different from the first interecho time, the tool establishing a magnetic field gradient in the earth formation wherein a depth of investigation corresponds with each frequency and the magnetic field gradient; relating the NMR data to a partial porosity at points (i,j) related to a first apparent transverse relaxation time (T 2,app,TE1,i ) obtained with (TE 1 ) and a second apparent transverse relaxation time (T 2,app,TE2,j ) obtained with (TE 2 ) to establish an NMR response model; solving the NMR response model to calculate at least one of the partial porosity and a fluid-filled pore volume at each of the points; summing at least one of the partial porosity and the fluid-filled pore volume for each of the points corresponding to each depth of investigation to provide at least one of a pore volume and a total fluid-filled pore volume; and associating at least one of each pore volume and each total fluid-filled pore volume with the corresponding depth of investigation to provide the parameter of interest.