Multiple-Phase Generation During Carbon Dioxide Flooding

Publisher Website
Google Scholar
Abstract
This paper describes research to determine the pressure and temperature region in which multiple phases are generated for selected reservoir oils displaced by CO2. The major purposes of this study were (1) to determine whether single-contact PVT conditions and multiple-contact flow generated multiple phases over equivalent pressures and temperatures, and (2) to determine whether multiple-phase generation would affect mobility. Multiple phases were generated for two reservoir oils of similar composition above the CO2 minimum miscibility pressures (MMP's) for temperatures between 307.5 and 322 K. For a limited temperature range, the pressures over which these multiple phases were observed agreed fairly well with those determined in single-contact PVT cell studies. However, multiple phases were also seen at higher temperatures in the multiple-contact displacements. Pressure-drop data as a function of CO2 injection volume were obtained for displacements within the multiple-phase region and for displacements conducted at pressures above the multiple-phase region. Comparison of these data indicates that multiple-phase generation reduces mobility within the flow system used. Mobility reduction would be beneficial during application of CO2 flooding on a reservoir scale.