The Effect of Thermal Steam Treatment Duration with Metallic Sodium Nanoparticles on Heavy Oil Upgrading

Abstract

The escalating share of hard-to-extract, highly viscous oil poses tangible challenges in the realm of oil extraction. Employing thermal steam treatment (TST) technology presents a promising approach, not only for viscosity reduction but also for comprehensive upgrading of extracted hydrocarbons within the reservoir itself. This study meticulously explores the impact of the TST duration, in tandem with organodispersed metallic sodium, on the upgrading of heavy oil sourced from the Ashalcha field. Through meticulous analysis utilizing gas chromatography, SARA analysis, IR spectroscopy, and GC-MS of individual fractions, the optimal duration for enhancing oil composition was pinpointed: 72 h at a temperature of 250 °C during TST. Remarkably, the utilization of sodium nanoparticles neutralizes hydrogen sulfide and carbon dioxide while concurrently catalyzing the degradation and reduction of asphaltenes, notorious for their adverse impact on oil rheology. Noteworthy findings include a discernible upsurge in low-molecular-weight hydrocarbons within the C1−C4 range, ascertained via gas chromatography. Additionally, analysis of saturated hydrocarbon composition using GC-MS highlighted a decline in compounds characterized by longer hydrocarbon chains. IR spectroscopy unveiled alterations in the asphaltene fraction, exhibiting reduced aromaticity attributable to the unfolding of cyclic structures and the elongation of hydrocarbon chains consequent to TST in the presence of a metallic sodium-based suspension.