What is the shape of pores in natural rocks?

The geometry of the internal space of porous media determines transport properties at all scales. We demonstrate an experimental scheme to quantify the body-to-throat ratio and the shape of the pores through direct measurements of geometrical quantities. We used a constant-rate mercury injection measurement to obtain the throat size and the pore-body volume, and an NMR method (DDIF) to obtain the pore size distribution in a Berea sandstone. This approach uniquely identifies the pore throats and bodies and enables a quantification of their sizes. Our results show that the pore bodies in Berea sandstone is likely to be described by a very much elongated cavity.