A relative volume of Rock Matrix (a part of the bulk rock volume \Omega_r consisting of solid rocks with no free fluids):
| (1) | \Omega_m = \Omega_r - \Omega_\phi |
where
\Omega_\phi | pore volume |
See also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics (PP) / Volumetric Rock Model