Experimental investigation on in-situ hydrogen generation from depleted heavy oil reservoir by gasification

AbstractFossil energy has been confirmed as the primary raw material for hydrogen generation in chemical factories. In-situ hydrogen generation from depleted oil reservoirs has been considered a prominent technology for hydrogen generation, accompanied by harmful gas storage, over the past few years. In this study, the effects of temperature, reaction time, distinct porous media, and oil/water ratio on hydrogen generation were investigated by simulating in-situ heavy oil gasification using high-temperature and high-pressure reactors. As indicated by the results, besides hydrogen, methane and carbon dioxide were also largely generated in the gasification process through water gas shift, oxidation, aquathermolysis, pyrolysis, and so forth. The result suggested that temperature and oil/water ratio exerted relatively significant effects on hydrogen generation due to the boosted forward reaction of water gas shift and steam reforming. Moreover, oxygen would prefer an oxidation reaction with oil instead of hydrogen. It was expressed that the hydrogen fraction decreased and remained constant as residence time went on due to less carbon monoxide generation, and arriving at equilibrium, whereas the gas yield tend to increase. The metallic oxides notably catalyzed hydrogen generation. Some novel insights gained in this study are conducive to achieving high-efficiency hydrogen generation through in-situ heavy oil gasification.Keywords: depleted oil reservoirgasificationheavy oilhydrogen generationmineral catalysis AcknowledgmentsWe also thank the anonymous reviewers for their constructive and valuable comments.Additional informationFundingWe would like to express our gratitude to the Science and Technology Project of Southwest Petroleum University (2021JBGS09), Central Government Funds of Guiding Local Scientific and Technological Development of Sichuan Province (2021ZYD0056) and Open Fund (PLN020-23) of State Key Laboratory of oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University).