Oil-Gas exchange

In BO and MBO PVT models when oil and gas phases reach chemical equilibrium the total mass of oil and gas components spread between oil and gas phases according to ambient pressure  $//<![CDATA[ \begin{array}{l}p\end{array} //]]>$ and temperature  $//<![CDATA[ \begin{array}{l}T\end{array} //]]>$.

Given a mixture of oil and gas sharing the same volume under pressure  $//<![CDATA[ \begin{array}{l}p\end{array} //]]>$ and temperature  $//<![CDATA[ \begin{array}{l}T\end{array} //]]>$ with

the total mass of oil component $//<![CDATA[ \begin{array}{l}m_O = m_{Oo}(p,T) + m_{Og}(p,T)\end{array} //]]>$

the total mass of gas component $//<![CDATA[ \begin{array}{l}m_G = m_{Gg}(p,T) + m_{Go}(p,T)\end{array} //]]>$

where

the mass share of oil component in oil phase  $//<![CDATA[ \begin{array}{l}m_{Oo}(p,T)\end{array} //]]>$ 

the mass share of oil component in gas phase  $//<![CDATA[ \begin{array}{l}m_{Og}(p,T)\end{array} //]]>$

the mass share of gas component in oil phase  $//<![CDATA[ \begin{array}{l}m_{Go}(p,T)\end{array} //]]>$ 

mass share of gas component in gas phase  $//<![CDATA[ \begin{array}{l}m_{Gg}(p,T)\end{array} //]]>$

are all functions of pressure  $//<![CDATA[ \begin{array}{l}p\end{array} //]]>$ and temperature  $//<![CDATA[ \begin{array}{l}T\end{array} //]]>$.

The quantitative measure of cross-phase exchange is given by Soliton GOR ( $//<![CDATA[ \begin{array}{l}R_s\end{array} //]]>$) and Vaporized Oil Ration ( $//<![CDATA[ \begin{array}{l}R_v\end{array} //]]>$):