Microbial Hydrogen From Depleted Oil Wells: Scaling, Costs & Challenges - CleanTechnica

The article discusses Gold H2, a Houston-based startup spun out from Cemvita Factory, which aims to produce hydrogen underground in depleted oil wells by injecting hydrogen-producing microbes and nutrients into the reservoirs. This process, called Black 2 Gold, leverages existing oilfield infrastructure to convert residual hydrocarbons into hydrogen and other gases, avoiding new drilling. The concept parallels microbially enhanced oil recovery (MEOR), a technique used since the 1980s to improve oil extraction by stimulating microbial activity, though MEOR has seen limited and niche application due to varying reservoir conditions. However, the article highlights significant challenges for microbial hydrogen production in depleted wells. Many reservoirs have unsuitable temperatures, salinity, or low residual hydrocarbons, limiting microbial activity and hydrogen yield. Contamination from past water injection, such as sulfate presence, can further reduce hydrogen production through chemical losses. Consequently, only a minority of depleted wells with moderate residual oil, appropriate salinity, and favorable temperature are viable candidates for this technology.