Thermally enhanced recovery, such as steam injection, of heavy oil in the presence of metal-ligand compounds can lower oil viscosity downhole, thereby improving its production. While catalytic chemistry has been proposed to be responsible for viscosity reduction, the interactions between metal-ligand compounds and crude oil components are poorly understood at the molecular level and the mechanism for viscosity reduction remains unknown. We thermally treated Peace River heavy oil using series of metal p-toluenesulfonate (M-PTS) compounds at 280 °C for 36 h. We quantified the viscosity change for the PTS complexes of nickel, zinc, silver, and iron, and compared the results against the sodium form. We analyzed reaction products using thermogravimetric analysis/mass spectrometry (TGA-MS) and gas chromatography/mass spectrometry (GC-MS) for chemical composition, and quantified the SARA components before and after treatment. Thermal-only treatment of Peace River oil lowered the viscosity by 39%. Thermal treatment with any of the PTS compounds reduced viscosity by an additional &gt;6%. We suggest that lower viscosity results from M-PTS compounds catalytically cracking certain chemical bonds in the heavier components, and from the PTS ligand and its decomposition products aiding in asphaltene disaggregation. The experimental observations shed new light on the role of catalysis in activating the oil fraction responsible for high viscosity.

Delineating heavy oil deviscosification catalytic chemistry of metal sulfonates

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.