An experimental investigation on phase behavior of a light oil and CO2

Abstract

The current oil frontier in Brazil is located in Santos and Campos Basin, where huge oil accumulations have been identified. Well tests have shown high pressures and high carbon dioxide concentration in these reservoirs. The characterization of the fluids existing in the reservoir rock is a key task for the better exploitation of the hydrocarbons. The objective of the paper is to present the results of an experimental PVT analysis of the oils found in the Brazilian pre-salt reserves in the region of Campos Basin using the same reservoir conditions of temperature and pressure. Dead oil and synthetic gas were recombined in laboratory to obtain the original live oil, which originally had 17.84% molar of CO2. Relevant data were collected and they are reported for oil and gas composition, formation volume factors, densities and viscosities at different pressures. A swelling test was also carried out through successive additions of carbon dioxide to the live oil from its original concentration up to 60.53% molar