Catalytic and Noncatalytic in Situ Hydrogen Production from Heavy Oil: A Review of Experimental Studies

Hydrogen (H₂) offers a less carbon-intensive energy production method than natural gas. The potential of utilizing hydrogen at a large scale within the future energy mix to fuel the world opens the door to investigating hydrogen production from heavy and extra-heavy oil reservoirs. Various reaction mechanisms are involved in the in situ combustion gasification of heavy oil to produce sustainable and low carbon intensive hydrogen. In-situ catalytic hydrogen production involves injecting a catalyst into the reservoir or utilizing the in situ reservoir materials to catalyze the various reactions. Clay minerals and formation water were found to serve as in situ catalytic materials and enhance the in situ hydrogen production process. This work presents a comparative review of the catalytic and noncatalytic experimental studies carried out on in situ hydrogen production. The formation damage induced by the in situ combustion and its effect on hydrogen production was highlighted. In addition, the impact of the formation damage induced by the in situ combustion on the hydrogen production process is discussed. This study categorized the experimental studies conducted on the hydrogen production from heavy oil into catalytic and noncatalytic processes to highlight the effect of the synthetic and natural reservoir catalytic materials on in situ hydrogen production.