Some geomechanical aspects of geological CO2 sequestration

Reservoir depletion and subsequent CO2 injection into the depleted geological reservoir induce stress changes that may mechanically damage top seal and wells, or trigger existing faults, creating the leakage pathways for CO2 escape from the reservoir. The role of geomechanics is to assess the mechanical impact of stress changes on seals, wells and faults. Since many hydrocarbon fields are geometrically complex and irregular, and the rock properties are spatially variable, such an assessment can be conveniently done with a numerical modeling of the field. Based on numerical analyses, recommendations can be given regarding the overall suitability of the depleted geological reservoir for CO2 disposal and safe CO2 injection.