Advanced Mud Gas Logging Techniques for Hydrogen Exploration

Abstract The exploration of natural hydrogen or "white hydrogen" has gained significant attention due to its potential as a clean and sustainable energy source. Unlike industrially produced hydrogen, which relies on energy-intensive processes such as steam methane reforming or electrolysis, natural hydrogen is generated through geochemical and biological processes within the Earth's crust. It can be continuously produced through reactions such as serpentinization, radiolysis of water, and deep subsurface and soil biological activity. This study investigates various degassing and gas analysis techniques for hydrogen detection while drilling, including real-time mass spectrometry at the wellsite and gas chromatography with thermal conductivity detection (GC-TCD). Particular attention is given to the calibration of mud-logging gas chromatographs equipped with mass spectrometry (GC-MS) to enable accurate quantification of hydrogen at low concentrations (e.g., below 5 ppm). Additionally, advanced analytical technologies such as cavity-enhanced Raman spectroscopy are explored as potential improvements for enhancing sensitivity and selectivity in hydrogen detection. A major challenge in hydrogen logging is the artificial generation of hydrogen when drilling with oil-based mud, which can be mitigated by analyzing alkene and carbon monoxide concentrations obtained from continuous logging or spot sampling. Addressing these challenges, the study proposes a workflow for quantitative hydrogen logging, contributing to the assessment of this resource in hybrid drilling scenarios, including oil and gas, geothermal applications, and dedicated hydrogen exploration wells.