SARA characterization and comparison for the ultra-heavy oil via combined analyses

Abstract

Structure characterization and comparison of the ultra-heavy oil and its four components are fundamental and crucial. In this work, nuclear magnetic resonance analyses were employed to quantitatively investigate carbon and hydrogen atom distributions. Combined with the gel permeation chromatography, elemental analysis, and X-ray diffraction results, average molecular structure parameters were determined for four components. Besides, an improved Brown-Ladner method was adopted to identify and adjust corresponding structural parameters, which considered influences of both heteroatoms (O, S, and N), and katacondensed or/and pericondensed system assumption on aromatic structures, compared with conventional methods. Moreover, molecular architectures of four components were respectively speculated and reconstructed based on this improved method, and the specific comparison reflected a higher accuracy. From this study, it could provide updated understandings on specific component structural information for the ultra-heavy oil to facilitate subsequent oil reactivity and simulation studies.