Radioactive Genesis of Hydrogen Gas under Geological Conditions: an Experimental Study

Abstract

The coexistence of hydrogen‐containing materials and radioactive substances in source rocks is universal. Few documents have researched whether the latter can radiate the former to generate hydrogen gas (H2) as well as the factors controlling this process. This work conducted a series of radiation experiments to address this issue. Samples were placed in sealed Pyrex glass containers and subject to cobalt (60Co) γ irradiation and components and contents of resultant gases were analyzed using gas‐chromatography. The results show that all the samples released variable amounts of H2 after irradiation and that the yield (H2) of decane is lower than that of 3‐tetradecylthiophene but higher than that of distilled water, which implies that a weaker H‐X bond energy (X indicates O, C or other element) in homogeneous materials corresponds with increased yield (H2). The yields (H2) of samples decreased with the decreasing solutions concentrations in sequence from mixed salts solution, KCl solution, Yellow Sea water, oil field water, gypsum solution to distilled water. The experimental results also show that the yield (H2) of distilled water with montmorillonite is higher than that of distilled water with kaolinite, because due to the larger specific surface area, ion exchange capacity and more effective energy transfer effect of montmorillonite. Meanwhile, the irradiation of oxygen‐ and carbon‐containing materials also releases O2 and CH4. The production of H2 via the irradiation of hydrogen‐containing materials makes the involvement of exogenous H2 into hydrocarbon generation possible, which can enhance the hydrocarbon volume and optimize crude oil.