CO2 Sequestration [Geomechanics]

If CO2 injection and its subsequent invasion in stressed deep saline aquifers or depleted hydrocarbon reservoirs could activate processes of mechanical failure as a function of pore-pressure changes, will it remain accountable for CO2-induced seismicity at any point of time in the future?

If so, then, depending on the ability of the aquifers/reservoirs to transfer stresses, which is more prone to happen following CO2 sequestration?

(a) near-well seismicity with an abrupt decay at larger distances; or,

(b) a longer-ranged seismic activity with a much slower decay at larger distances?

In case, if the poroelastic effects in the aquifer/reservoir remain to be captured by Biot-Willis coefficient, then, whether the presence of elastic stresses in deep saline aquifer or depleted hydrocarbon reservoir (in the long run) would lead to earthquake triggering far away from the injection point?

Suresh Kumar Govindarajan 07-Dec-2024