Foamy Oil Behaviour in Solvent Based Production Processes

Abstract

Abstract Foamy oils, generated during cold production, have also been detected in solvent based recovery processes. Understanding the foamy oil mechanism is key to determining how oil is produced in processes such as Cyclic Solvent Injection (CSI). Visual observations of solvent exsolving from solution during depressurization were performed to gain a better understanding of these processes. Heavy oil saturated with CO2, CH4, C3H8 and a combination of CO2 and C3H8 are examined in an etched glass micromodel. Three different expansion rates are examined. The results indicate that CO2 and CH4 show an extreme supersaturation. CO2 saturated oil produces more nucleation sites than CH4, C3H8 and a mixture of CO2 and C3H8. Approximately 8 times more nucleation sites were produced with CO2 than with CH4. With more nucleation sites, there is a greater potential for oil recovery with solution gas drive. The experiments conducted here provide a qualitative understanding of the foamy oil process and aid in the understanding of solvent based enhanced oil recovery mechanisms such as Cyclic Solvent Injection (CSI).