Pore sizes and pore connectivity in rocks using the effect of internal field.

A novel nuclear magnetic resonance method has been applied to several sandstone rocks to measure the pore size distribution using the magnetization decay due to diffusion in the internal magnetic field (DDIF). By comparing the results of the DDIF and Hg porosimetry experiments, a clear picture of pore connectivity emerges. The pore body diameter can be defined using the DDIF data and is found to have a clear trend as a function of porosity.