Revisiting the methodology for asphaltenes precipitation

摘要: Abstract The world increase in energy demand has directed the petroleum industry to exploit unconventional oil reserves such as Brazilian Pre-Salt reservoirs. Production conditions verified those reservoirs enhance occurrence of asphaltene precipitation well correlated problems. Asphaltenes are known a solubility class. Such classification makes tough determination consistent chemical properties for these compounds. In this scenario, study aims analyze influence standard methodologies upon characteristics. Three oils were selected, which hereinafter called BR1, BR2, and BR3. Oil BR1 was produced from Post-Salt reservoir while BR2 BR3 originated one. asphaltenes extracted through by n-heptane according ASTM 2007, 6560 (IP-143), so-called SOHXLET, NUESC methodology. Asphaltene fractions characterized regarding their composition (FTIR) thermal stability (DSC). results showed that endothermic events typically registered compounds strange commonly accepted verified. Also, degradation temperature varied method. turn, FTIR spectra detected peak is usually associated with naphthenic acids (3500 cm−1). Therefore, analysis confirmed what indicated thermograms. summary, it concluded used 2007 methodology precipitated complex composed wax acids. Thus, present work suggested starting point analyses implications on crude behavior.