Fluid Mobility

Once we have the basic pore size distribution from the NMR data, a number of useful petrophysical parameters can be quickly and easily inferred. Using two basic NMR pore distributions, one on a saturated core and one on the same core that has been centrifuged, it becomes relatively easy to calculate Total Porosity, Bound Volume Index (BVI), Free Fluid Index (FFI), Clay Bound Water (CBW), and Permeability.

The area under the saturated T2 curve gives the total porosity (ΓΈ). The area under the centrifuged curve provides the BVI and the difference between the two is the FFI. Finally, using either the Coates or Schlumberger model, permeability can be estimated from relaxation data.