$//<![CDATA[ \begin{array}{l}\displaystyle \ln p_b = 1.7669 + 1.7447 \, \ln p^*_b - 0.30218 \,\big( p^*_b \big)^2\end{array} //]]>$, $//<![CDATA[ \begin{array}{l}\displaystyle p^*_b = \left( \frac{R_s}{\gamma_g} \right)^a \, T^b \, \gamma_{API}^c\end{array} //]]>$

$//<![CDATA[ \begin{array}{l}a = 0.816, \, c = -0.989\end{array} //]]>$

$//<![CDATA[ \begin{array}{l}b = \begin{cases} 0.172 & \mbox{for Black Oil} \\ 0.130 , & \mbox{for Volatile Oil} \end{cases}\end{array} //]]>$