Carbon Sequestration is a process where CO2 is liquefied and pumped inside the earth’s subsurface, with the goal of reducing atmospheric pollution. One of the possible sites for that to take place concerns abandoned oil and gas reservoirs. However, it is very important to assess the structural reliability of the abandoned wells (both the surrounding rocks and the cement) as CO2 leakage can be dangerous to nearby communities. The degradation process of the cement and rocks in a CO2 sequestration site is very complex and involves multiple processes that span large temporal and spatial scales. These include chemical reactions, fluid flow, and fracture evolution. Currently, we are working towards the development of a computational model capable of coupling all these processes together, with the goal of understanding how failure can occur and how to prevent it.