ASPHALTENIC CRUDE OIL CHARACTERIZATION: AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF RESINS ON THE STABILITY OF ASPHALTENES

ABSTRACT High performance liquid chromatography (HPLC) and Thin Layer Chromatographic (TLC) latroscan were used to characterize an asphaltenic stock tank oil (STO) from the North Sea. The whole STO was separated into saturates, aromatics, polars 1 (resins 1), polars 2 (resins 2) and asphaltene fractions. The separated resins (1) and the more polar resins (2), also termed asphaltene peptizing agents, were further characterized by HPLC in terms of their neutral, basic, pyrrolic and acidic components. Resins (1) and resins (2) were mixed in different proportions with whole (original) STO; the resulting mixtures were tested for asphaltene onsets of precipitation due to n-C5 injection at 25° C and 690 kPa. Results of these tests are presented and the observed trends are explained in terms of resins characters and/ or major constituents.