The role of geophysics in geologic hydrogen resources

Abstract Transition to cleaner energy sources is crucial for reducing carbon emissions to zero. Among these new clean energy types, there is a growing awareness of the potential for naturally occurring geologic hydrogen (H2) as a primary energy resource that can be readily introduced into the existing energy supply. It is anticipated that geophysics will play a critical role in such endeavors. There are two major different types of geologic H2. One is natural H2 (referred to as gold H2), which is primarily accumulating naturally in reservoirs in certain geological setting; and the other is stimulated H2 (referred to as orange H2), which is produced artificially from source rocks through chemical and physical stimulations. We will first introduce geophysics in geologic H2 in comparison and contrast to the scenarios of blue and green H2. We will then discuss the significance of geophysics in both natural H2 and stimulated H2 in term of both exploration and monitoring tools. Comparing and contrasting the current geophysical tools in hydrocarbon exploration and production, we envision the innovative geophysical technologies and strategies for geologic H2 resources based on our current understanding of both natural and stimulated geologic hydrogen systems. The strategies for H2 exploration will involve a shift from reservoir- to source rock-centered approaches. Last, we believe that the geophysical methods including integration of multi-geophysics, efficient data acquisition, and machine learning in geologic H2 could be potentially provide sufficient new directions and significant opportunities to pursue research for the next one or two decades.