Geoengineering the Subsurface

Underground Storage of Fluids

Anthony Clark
Laboratory Manager

Tiziana Vanorio
Faculty

The underground storage fluids (gases and liquids) has the goal of storing energy (e.g., H₂ or Methane) and residual products (e.g., CO₂) in underground caverns, in the pore space of rock formations, or through the mineralization of the fluid into stable solid minerals. We are studying Whatever the technology, fluid storage in porous solid media involves chemical processes. We are studying the effect of these processes on the physical and mechanical properties of the host rock.

Carbonation

Anthony Clark
Laboratory Manager

CO₂ is injected at supercritical conditions (scCO₂), which provide CO₂ with the diffusivity of a gas and the the solvating power of a liquid. Carbonation is a reaction between CO₂ and metal oxides or silicates that leads to the formation of calcite or other carbonate minerals. This type of mineralization of CO₂ decreases permeability and increases the brittleness of the material.

Dissolution

Anthony Clark
Laboratory Manager

Tiziana Vanorio
Faculty

When carbon dioxide reacts with water, carbonic acid is formed, increasing the acidity of the system. The carbonic acid can react with the host rock and consequently can alter the rock structure and pore geometry with effects on flow and mechanical properties such as permeability and strength.

Methanation

Methanation is a reaction that converts carbon dioxide to methane through hydrogenation. Specifically, in the presence of a catalyst (e.g., nickel, ruthenium, or rhodium), hydrogen and carbon dioxide react at elevated temperatures to produce methane and water. The natural weathering process of ophiolites and ultramafic rocks produces laterite deposits with a nickel content of 1.65 - 2.40%, which can make them methane generating source rocks. Experiments are needed to study under what geological conditions abiotic methane can be generated.