CO2 Sequestration in Basaltic Formations: Indian Scenario
1. Despite Basaltic rocks (mafic) having a relatively higher content of divalent ions (Ca2+, Mg2+, Fe2+), whether, the Indian Basaltic formations, identified for CO2 sequestration, have favorable mineral compositions as well including pyroxene and Olivine?
Has favorable mineral composition containing enhanced fractions of ferromagnesian silicates?
If yes, will it be mafic or ultramafic rocks? Do we have significant ultramafic rocks with elevated amounts of magnesium along with enhanced dissolution rate of pyroxene?
2. Upon injecting dissolved CO2, how fast will it lower the pH of the formation water?
Can we have a control over the extent by which the reactivity gets enhanced?
When exactly hydrogen ions begin to attack the basaltic rocks?
Upon attacking the Basalts, whether, all the divalent ions (Ca2+, Mg2+ & Fe2+) will be released simultaneously into the formation solution?
If not, how do we monitor the fractions on the formation of Calcite, Magnesite or Siderite?
Despite having control over the composition of the injected fluid, would it remain feasible to monitor the entire process of precipitation and dissolution in the absence of having control over
(a) thermodynamic stability of the divalent cations present in Basalts; and
(b) the solubility rates of minerals?
3. Whether the identified Basaltic Formations have enough potential for CO2 storage?
4. With Basalt’s internal fractures formed during the cooling of lava that essentially enhance both porosity and permeability, how could these formations be devoid of fractures and fault reactivation?
Or
Should we focus on maximizing the surface area for mineral-CO2 interactions, which requires the presence of fractures, and which will aid smooth downstream migration of injected CO2?
5. How could we ensure the presence of vesicles that would aid the injected CO2 plume migration?
6. Since, in Basalts, water is to be injected with dissolved CO2 into reactive Basalt rocks, towards mineralization of CO2 for permanent storage, how about the requirement of huge quantum of water for the mineralization process?
7. Would it remain feasible to finalize the location and subsequently monitor the resulting in-situ mineralization of the injected CO2, given the heterogeneous and anisotropic nature of basalt formations (resulting from their complex original depositional environment)? Also, how will we have a control over the connectivity between the presence of divalent ions in Basaltic formation and the solution’s alkalinity, that control the rate of carbon mineralization?
8. Do we have areas with an enhanced geothermal gradient (to promote mineral precipitation) towards locating CO2 injection sites?
9. To what extent, the storage capacity of the Basalt rocks will get modified upon mineral carbonization?
10. How exactly to tackle the pressure builds up in a Basaltic reservoir that leads to reduced injectivity upon quick carbonation and also resulting from clogging of pore throats in the vicinity of wellbore?