Enhanced oil recovery (EOR) refers to a set of techniques used to extract additional oil from reservoirs after the primary and secondary recovery processes have been exhausted. The goal of EOR is to increase the amount of crude oil that can be extracted, thereby improving overall recovery rates.

There are three main categories of EOR techniques. Thermal recovery involves injecting steam or hot water into the reservoir to reduce the viscosity of heavy oil, making it easier to flow. Gas injection entails injecting gases like carbon dioxide (CO2) or natural gas into the reservoir to help push oil toward production wells or to reduce oil viscosity. Chemical EOR involves injecting chemical agents, such as surfactants or polymers, to alter the properties of the oil and the reservoir rock, enhancing oil displacement and mobility.

The integration of liquid hydrogen in EOR can enhance these traditional methods by improving oil recovery rates, lowering viscosity, and potentially reducing carbon emissions. Using hydrogen can also maintain reservoir pressure and enable the co-production of hydrogen, making the overall extraction process more efficient and sustainable. This approach aligns with current energy transition goals, addressing both the demand for oil and the need for cleaner extraction methods.