Genesis and energy significance of natural hydrogen

H2 is clean energy and an important component of natural gas. Moreover, it plays an irreplaceable role in improving the hydrocarbon generation rate of organic matter and activating ancient source rocks to generate hydrocarbon in Fischer-Tropsch (FT) synthesis and catalytic hydrogenation. Compared with hydrocarbon reservoir system, a complete hydrogen (H2) accumulation system consists of H2 source，reservoirs and seal. In nature, the four main sources of H2 are hydrolysis, organic matter degradation, the decomposition of substances such as methane and ammonia, and deep mantle degassing. Because the complex tectonic activities, the H2 produced in a geological environment is generally a mixture of various sources. Compared with the genetic mechanisms of H2, the migration and preservation of H2, especially the H2 trapping, are rarely studied. A necessary condition for large-scale H2 accumulation is that the speed of H2 charge is much faster than diffusion loss. Dense cap rock and continuous H2 supply are favorable for H2 accumulation. Moreover, H2O in the cap rock pores may provide favorable conditions for short-term H2 accumulation.