The quantitative measure of solution gas:
R_s = \frac{V_{Go}^{\LARGE \circ}}{V_{Oo}^{\LARGE \circ}} =
\frac{m_{Go}}{ m_{Oo}} \cdot \frac{\rho_O^{\LARGE \circ}}{\rho_G^{\LARGE \circ}} where
V_{Go}^{\LARGE \circ}= \frac{m_{Go}}{\rho_G^{\LARGE \circ}} – STP volume of natural gas component of mass
m_{Go} and STP density
\rho_G^{\LARGE \circ}
R_s(p, T) is a function of pressure and temperature due to oil-gas exchange
V_{Oo}^{\LARGE \circ}= \frac{m_{Oo}}{\rho_O^{\LARGE \circ}} – STP volume of dead oil component of mass
m_{Oo} and STP density
\rho_O^{\LARGE \circ}