Mass balance equation

The mass balance equation is an equation that relates densities of a rock with its porosity. The equation is as follows:


 * $$\rho=\phi \rho_\mathrm{f} + (1 - \phi) \rho_\mathrm{m}\ $$

where $$\phi$$ is the total porosity, $$\rho$$ is the measured bulk density, $$\rho_\mathrm{m}$$ is the density of the rock matrix, and $$\rho_\mathrm{f}$$ is the density of the saturating fluid.