Analysis of CO2 Migration in Horizontal Saline Aquifers during Carbon Capture and Storage Process

Abstract

The storage of CO2 has become an important worldwide problem, considering that an excess of CO2 in the Earth’s atmosphere causes dramatic changes in its climate. One possible solution is to remove the excess of CO2 from the atmosphere, capture it in the process of creation, and store it safely, negating the possibility of its return into the atmosphere. This is the process of Carbon Capture and Storage (CCS). In the following paper, the authors investigate horizontal saline aquifers and their ability to store CO2. The authors’ application of sensitivity analysis on horizontal migrations uncovered that CO2 permeability and aquifer porosity have a considerable impact on horizontal migrations. During the migration process, CO2 can reach tens of kilometers from its injection point. By introducing effective CO2 density to the conduction velocity term, the authors showcase that the convection-diffusion equation for compressible fluids can be replaced with the equation for incompressible fluids. The buoyancy factor in convective velocity is as density dependent as in conduction velocity. By means of introducing an effective density to the aforementioned term, the process of transport via variable convective velocity can be substituted for a process which is effective, constant, and not density dependent.

Enhancing Carbon Capture and Storage Deployment in the EU: A Sectoral Analysis of a Ton-Based Incentive Strategy

“…In the same research, an approach for evaluating the suitability of different geological formations for CO 2 storage is provided, and DSAs are categorized as very effective in terms of CO 2 storage, with relatively low safety risks and mitigation of CO 2 . On the other hand, other research has analyzed horizontal DSAs and concluded that long injection periods and high injection rates can increase the radial migration of CO 2 and make leakage probable when CO 2 finds an upward pathway in the aquifer [60].…”

Impact of Regional Pressure Dissipation on Carbon Capture and Storage Projects: A Comprehensive Review

“…Understanding CO 2 plume migration within aquifers is essential for ensuring the long-term integrity of CCS projects. When CO 2 is injected into an aquifer, it ours differently from the liquid phase of water [106]. CO 2 is less dense than brine, which is the predominant fluid in saline aquifers, and therefore tends to rise within the formation.…”