A specific case of cross-phase fluid 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  and temperature .

Given a mixture of oil and gas sharing the same volume under pressure  and temperature  with

the total mass of oil component

the total mass of gas component

where

the mass share of oil component in oil phase  

the mass share of oil component in gas phase 

the mass share of gas component in oil phase  

mass share of gas component in gas phase 

are all functions of pressure  and temperature .

The quantitative measure of cross-phase exchange is given by Soliton GOR () and Vaporized Oil Ration ():