CO2 Sequestration
1. Whether ‘induced seismicity’
(albeit, mostly, micro-seismic events with magnitude lesser than 3;
its cumulative effect over a long period – upon reaching, yield point)
would be able to destroy the cap-rock; and in turn,
whether, CO2 would get escaped
through the least resistive damaged paths;
and eventually,
would reach the ground surface?
2. If yes, then,
the spatial distribution of such induced seismicity
would be covering
a relatively larger areal/volumetric extent -
as the injected CO2 gets transported
relatively far away from the injection well
due to the relatively higher permeability of the reservoir?
3. Following the injection of supercritical CO2,
if the reservoir pore-pressure gets build-up; and, in turn,
if the effective stress offered by solid grain network gets reduced; and, in turn,
if the injection process tends to destroy the initial reservoir stress equilibrium condition significantly, and, in turn,
if the reservoir rock formation encounters a major mechanical failure, and in turn,
if the reservoir rock mass releases a significant amount of stored energy in the form of seismic waves; then,
whether the contribution by
(a) Pore pressure perturbation would remain to be significant and dominant?
OR
(b) Pore pressure diffusion caused by CO2 injection would remain to be significant and dominant?
OR
(c) Both (a) & (b) along with thermal stresses resulting temperature variation and stress corrosion resulting from long-term chemical reaction by injected CO2: All of these mechanisms would play a crucial role
in generating, the resulting induced seismicity - to be of a concern?