Effects of elemental sulfur and sulfur-bearing minerals on the thermal evolution of aromatic compounds in solid bitumen

Abstract

Previous studies have shown that some of the aromatic compound parameters have good correlation with the maturity of organic matter. However, it is still unknown whether the widely used aromatic maturity-related parameters are available with the co-existence of sulfur (elemental and/or sulfur-bearing minerals). Artificial simulation experiments of solid bitumen together with elemental sulfur and/or sulfur-bearing minerals (e.g., pyrite, ferrous sulfate, iron sulfate, and calcium sulfate) were carried out to investigate the influence of elemental sulfur and sulfur-bearing minerals on the thermal evolution of aromatic compounds. Results illustrated that some reactions including methylation, alkyl rearrangement and demethylation of aromatic compounds were affected with various extents by the existence of elemental sulfur and sulfur-bearing minerals. Thus, the applicability of the aromatic index should be careful. This study also found some parameters that still can effectively evaluate the maturity of organic matter in the sulfur-bearing environment, such as 1,2,3-TMN/2,3,6-TMN, P/(P+∑MP), MPI and 4,6-DMDBT/3,6-DMDBT.

Keywords

• elemental sulfur
• sulfur-bearing minerals
• aromatic compound
• maturity parameter
• thermal simulation experiment
• solid bitumen
• sichuan basin