Viability of the steam-based extraction of extra-heavy crude oil using nanoparticles: Exergy and life-cycle assessment

The growing energy demand has prompted the research community to seek more efficient and sustainable resource extraction methods, particularly in the case of crude oil. Investigating the potential of nanotechnology to enhance crude-oil recovery from extra-heavy and heavy crude-oil reserves is crucial for optimizing resource utilization, improving economic viability, minimizing environmental impacts, driving technological advancement, ensuring energy security, and meeting market demands. In this study, we investigated the implementation of exergy analysis (ExA) on nanotechnology in oil-recovery processes, which has not previously been explored. This involved a life-cycle assessment (LCA) to evaluate the environmental impacts and to complement the ExA in order to optimize operations. To environmentally and thermodynamically analyze the extraction process of extra-heavy crude oil, four scenarios were evaluated: i) steam injection at 0.5 quality; ii) steam injection at 1.0 quality; iii) steam injection at 0.5 quality with 500 mg L⁻¹ of nanoparticles; and iv) steam injection at 1.0 quality with 500 mg L⁻¹ of nanoparticles. The nanofluids used (AlNi1 and AlNi1Pd1) consisted of 500 mg L⁻¹ of alumina (Al₂O₃) doped with a 1.0 % mass fraction of nickel (Ni) (i.e., AlNi1), and the same amount of alumina doped with a 1.0 % mass fraction of Ni and palladium (Pd) (i.e., AlNi1Pd1). Both nanofluids were supplemented with 1000 mg L⁻¹ of Tween 80. The experiments were conducted in a laboratory and numerical simulation was used to upscale the different scenarios. Considering the equilibrium K-values model, a multiphase/multicomponent flow model coupled with an energy transport equation was utilized. Nanocatalyst transport, as per the experimental data, involved non-equilibrium transference between the liquid phases and the rock surface. The laboratory data were used to calibrate the model, which was then scaled up to reservoir conditions to estimate the oil recovery obtained from deploying in-situ upgrading processes at the field scale. Exergy calculations were performed on the involved flows and porous media in order to assess the crude-oil quality throughout the process. An LCA was implemented to evaluate the reduction in environmental impact achieved by using steam injection at X = 1.0 quality, with and without nanoparticles. The results of the ExA showed that using nanoparticles allowed crude oil with a higher energy quality to be obtained. Furthermore, the ExA showed that the increase in steam quality had a more significant effect on the exergy destroyed in the process than the use of nanomaterials, demonstrating the good performance of the proposed technology. Environmental analyses showed that marine ecotoxicity, urban land occupation, particulate matter formation, and global warming potential were the most-impacted categories, significantly contributing to total environmental impacts, after the fossil depletion impact category for all scenarios. In conclusion, using bimetallic nanoparticles in crude-oil extraction produces a better product with better energy and environmental performance.