Authors: F. Rodriguez | Hadi Belhaj | Aysylu Askarova | Tatiana Alekhina | R. Morales | María Llamedo | A. Mendoza‐Galván | C. Bejarano | Аlexey Cheremisin | Morteza Hosseinpour | Fausto Posso | Mohammed Aldhuhoori
Source:  (article, 2025-04-21)
Field: Chemistry — Analytical Chemistry

Modeling In-Situ Catalytic Upgrading and Hydrogen Production from Unconventional Extra-Heavy Oil Reservoirs: First Results of a Reference Case in the Orinoco Oil Belt “La Faja Petrolífera Del Orinoco” - Venezuela Abstract Modeling the in situ combustion (ISC) process in the presence of chemical additives (i.e., catalysts and hydrogen donors) is challenging due to the multiple chemical reactions that occur in the process (e.g., hydrocarbon combustion, thermal-cracking, water-gas shift, coke gasification, etc.). The objective of this study is to model numerically the in situ catalytic upgrading of crude oil process using experimental data from the Orinoco Oil Belt and a hydrogen generation method available in a commercial numerical simulator, which will allow considering the effect of the catalyst in improving crude oil properties and in providing a better understanding of the mechanisms involved in the process. ISC combustion tests with catalysts (nanoparticles of a transition metal) and hydrogen donors have been carried out in Venezuela for extra-heavy crude oil reservoirs of Eastern Venezuela Basin, aiming at the stabilization of the combustion front and improving physical-chemical properties of the crude oil. In this article, the numerical simulation was based on results of combustion tube tests with catalysts (pre-packed combustion cells) performed at reservoir conditions (8.5 °API, unconsolidated sandstones,4500 cP at 50°C) of the Orinoco Oil Belt heavy oil reserves. The kinetic model used in the numerical simulation considers the upgraded component, as well as the hydrogen and the catalyst components. The history matching ISC tests with catalysts was carried out using a machine learning tool, and the outputs were applied to field upscaling by a cluster of wells in the Orinoco Oil Belt. Experimental results from in situ combustion tests with catalyst show an improvement in crude oil properties, mainly in API gravity and viscosity, as well as a reduction in asphaltene content, a high generation of light compounds and a higher recovery factor greater than 90%. The experimental outcome also highlights the effect that mineralogy of the reservoir-rock may have on the in situ upgrading process. An acceptable match of experimental variables such as API, thermocouple temperature, oil recovery, gas composition is obtained. The main mechanisms involved in crude oil upgrading and hydrogen production are analyzed and illustrated in detail. Predictions of the cumulative oil production, gas composition and coke concentrations, temperature and oxygen distributions, as well as sensitivity analyses of the critical variables (e.g., injection rate) in the evaluated sector model of the field are presented and discussed in this article. This paper presents a workflow for modeling in situ catalytic upgrading and in situ hydrogen production from Venezuelan highly viscous oil reservoirs, with potential application worldwide. This study contributes to the development of technologies for in situ hydrogen production, as well as for the management of acid gases in order to accelerate the energy transition to net-zero carbon in 2050. Gasoline ; Petroleum engineering ; Environmental science ; Unconventional oil ; Oil production ; Waste management ; Geology ; Fossil fuel ; Engineering Petroleum Processing and Analysis ; Reservoir Engineering and Simulation Methods ; Enhanced Oil Recovery Techniques