In-Situ upgrading technology: Nanocatalyst concentration levels effects and hydrocarbons paths in the porous medium

Abstract

The current research work contributes one further step in developing the heavy oil in-situ upgrading technique. The experimental work was carried out using a dolomite corepack as a porous medium at temperature and pressure already investigated in In Situ Upgrading Technology (ISUT). Crude oil was saturated in the corepack to simulate the oil in place in the reservoir; then, hot vacuum residue (VR) plus nanocatalyst, and in the presence of hydrogen (H2) was continuously injected into the porous medium. The nanocatalyst was composed of ultradispersed Ni–Mo and deposited in three incremental steps in the corepack. Depositing catalyst in the corepack aimed to create a reactor in which upgrading reactions can occur. After each incremental nanocatalyst deposition step, the hot VR and H2 continuously flowed at a selected temperature, pressure and residence time through the corepack. The products of every VR plus H2 step were analyzed with techniques such as microcarbon (MCR), simulated distillation (SimDist). The products from the stage with the highest catalyst concentration were determined to have lower VR contents, much lower viscosities, lower sulfur content, and stability; this latter indicating the necessity of carefully controlling processing severity levels. Chemical tracers were added to the crude oil (Phenanthrene) and the VR (1-methylnaphthalene and n-octadecane) at a 1.0 wt% level; their distributions were studied throughout the process via chromatography and mass spectrometry analyses. Cracking, plus olefin and aromatic hydrogenation reactions were evidenced to occur during the ISUT process.