A This article focuses on the study of physicochemical processes occurring during the filtration of carbonated water through a porous medium simulating an oil reservoir. The aim of the research is to understand the mechanisms of enhanced oil recovery (EOR) and to assess the possibilities of CO2 sequestration in depleted reservoirs. The experiments were conducted in a dynamic mode, which allowed approximating laboratory conditions to real technological processes. The relevance of the work is due to the insufficient understanding of chemical reactions during the injection of carbonated water, which limits the effectiveness of existing technologies. The scientific novelty lies in the experimental confirmation of hydrocarbon synthesis, including methane, ethane, propane, and heavy hydrocarbons (С10–С20), under conditions simulating natural processes, which supports the biospheric concept of oil and gas genesis. The dependence of hydrocarbon yield on pressure, filtration rate, and contact time with the catalyst was established. The main results include the formation of hydrogen (68–85% vol.), methane (5–12%), ethane (0.2–0.8%), propane (0.1–0.5%), and carbon monoxide (0.3–1.2%) during filtration through iron filings. Deposition of heavy hydrocarbons on the catalyst was observed, and the concentration of hydrogen increased with increasing pressure from 3 to 12 atm. The Fischer-Tropsch mechanism was confirmed as the main pathway for hydrocarbon synthesis. The obtained data are important for the development of EOR and CO2 sequestration technologies, as well as for deepening the knowledge of hydrocarbon formation processes in nature.