A New Approach Utilizing Liquid Catalyst for Improving Heavy Oil Recovery

Abstract

Chemicals-assisted enhanced oil recovery (EOR) has recently received a great deal of attention as a means of improving the efficiency of oil recovery processes. Producing heavy oil is technically difficult due to its high viscosity and high asphaltenes content, therefore, novel recovery techniques are frequently tested and developed. The present study contributes to general progress in this area by synthesizing an acidic Ni-Mo-based liquid catalyst (LC) and employing it to improve heavy oil recovery from sand-pack columns for the first time. To understand the mechanisms responsible for improved recovery, the effect of the LC on oil viscosity, density, interfacial tension (IFT), and Saturates, Aromatics, Resin, and Asphaltenes (SARA) contents were assessed. The results show that heavy oil treated with an acidic Ni-Mo based LC has reduced viscosity and density, and that the IFT of oil-water decreased by 7.69 mN/m, from 24.80 mN/m to 17.11 mN/m. These results are specific to the LC employed. The results also indicate that the presence of the LC partially upgrades the structure and group composition of the heavy oil, and sand-pack flooding results showing that the LC increased the heavy oil recovery factor by 60.50% of the original oil in place (OOIP). Together, these findings demonstrate that acidic Ni-Mo based LCs are an effective form of chemicals-enhanced EOR and should be considered for wider testing and/or commercial use.

Molecular Characterization of Remnant Polarizable Asphaltene Fractions Upon Bitumen Upgrading and Possible Implications in Petroleum Viscosity

“…Viscosity improvement also arises from increasing the content of saturates and aromatics, with a concurrent decrease of the concentration of sulfur and other molecular features such as aromaticity. 14,15 The improvement of methods for viscosity reduction via in situ upgrading requires comprehensive investigation of the molecular changes induced by cracking and addition reactions that occur during common processes such as thermal treatment and hydroprocessing. It is also critical to understand how these changes correlate with petroleum bulk properties (i.e., viscosity and API gravity).…”

“…Generally, the goal of upgrading extra-heavy oils, via methods such as visbreaking and hydroconversion, is viscosity reduction, via cracking reactions to decrease molecular weight and/or disruption of intermolecular interactions that likely promote strong aggregation among specific petroleum fractions (e.g., asphaltenes). − Therefore, it is likely that viscosity reduction upon upgrading results from a decrease in the concentration of asphaltenes and resins, known for their higher heteroatom content and stronger aggregation tendencies. Viscosity improvement also arises from increasing the content of saturates and aromatics, with a concurrent decrease of the concentration of sulfur and other molecular features such as aromaticity. , …”