Carbon dioxide (CO2) is one of the main greenhouse gases released to the atmosphere mainly from the burning of fossil fuels, such as coal, oil and natural gas, which currently supply around 85% of the world’s energy needs. Moreover, due to the low relative cost and abundance of fossil fuels, it is likely that fossil fuels will govern the economy for at least the next 25 to 50. Therefore, it is necessary to have proper CO2 emission control techniques to create a safer atmosphere for human beings. Geosequestration of carbon dioxide (CO2) in deep saline aquifers is one of the most feasible approaches to mitigate global warming. However, dissolution of injected CO2 in brine has some effects on chemical diffusion, failure strength and permeability in the reservoir rock. There is also a significant variation in the mineral composition of reservoir rock upon exposure to CO2, which changes the mineralogical and micrological structure of the rock mass and consequently changes the hydro-mechanical properties of the rock. Therefore, this research provides a comprehensive study of the potential changes in aquifer mechanical properties and permeability characteristics caused by injected CO2 under in situ conditions, highlighting the factors affecting the integrity of sedimentary rock properties.

In this research work, basically the following methods will be used;

  1. Laboratory experiments high temperature and high pressure tri-axial set up.
  2. Acoustic Emission (AE) to study crack propagation strength thresholds.
  3. Numerical modelling (COMSOL) to study the flow and strength behaviour of reservoir rock under different pressure and temperature conditions. These modelling results will be compared with laboratory experiments.
  4. Empirical modelling to improve the existing formula for reservoir rock failure strength, to suit deep underground conditions (pressure, temperature and fluid medium)