The Government of India announced its commitment to reach net-zero greenhouse gas emissions by 2070 at the recent COP 26 summit. Modeling projections suggest that meeting this target would likely require substantial amounts of CO2 capture and storage (CCS) from large-point sources (LPS). Our analysis first reveals the key co-benefits for India in the adoption of CCS, viz. energy security, lower aggregate costs of carbon mitigation, higher resilience and lower stranded assets. For instance, we estimate that stranding of >100 GW and >70 GW of coal- and gas-fired power capacity could be avoided with the presence of CCS in the power sector mix.This analysis is further supplemented by our recent estimates on CO2 storage potential estimates in Indian geologic formations. Our results indicate that the storage capacity via enhanced oil recovery (EOR) is 1.2 GtCO2 after incorporating engineering and geologic constraints. Similarly, the storage capacity in unminable coal fields is estimated to be 3.5-6.3 GtCO2. Even though the combined storage potential in these formations is constrained, they should be actively considered within policy-making as they predominantly lie within areas of dense areas of LPS, thus creating possibilities of CCS hubs and clusters. In addition, 291 GtCO2 could be sequestered in saline aquifers and 97-316 GtCO2 in basalts; though, these values are subject to higher uncertainties. A number of saline aquifers may be characterized as having storage potential equivalent to several years of LPS emissions (>10 GtCO2) along with high storage feasibility.Our ongoing analysis attempts a more evolved approach towards source-sink mapping in India by combining the storage potential estimates with geospatial layers of LPS. Large power plants, which emit >20 MtCO2 annually, and high-purity CO2 sources such as refineries, are of particular interest. Preliminary source-sink mapping results show substantial clustering opportunities in eastern India, which has active coalbed methane extraction undertaken by five companies, and western India, with large industrial sources interspersed with EOR sites. The results of this analysis will also inform decision-makers on future LPS siting opportunities if a policy thrust on CCS is undertaken for meeting net-zero targets over the next two decades.

A document by Yashvardhan Verma. Click on the document to view its contents.

CO2 enhanced oil recovery (EOR) is being increasingly deployed for the exploitation of depleted conventional oil and gas fields, due to the twofold benefit of improved recovery efficiency and reduction in carbon dioxide emissions. Geomechanics starts playing an increasingly important role with the injection of CO2 in the subsurface and the subsequent pore pressure buildup. However, the release of pressure through oil production enables a higher amount of CO2 to be introduced into the ground without causing undesirable effects. Understanding the stress perturbation due to fluid injection and withdrawal aids in comprehending the fault activation mechanism and the risks of induced seismicity. The current study evaluates the geomechanical influence of CO2 injection for enhanced oil recovery in a depleted oil field, and assesses the risk of injection and production induced seismicity as a constraint in geologic containment of CO2. The Ankleshwar field in Cambay basin in India is chosen for the study. The field is a potential CO2 EOR site due to its excellent permeability and recovery efficiency. Coupled multiphase fluid flow modeling and geomechanical analysis were carried out to study the hydro-mechanical characteristics of CO2 injection and fluid production. The rise in pore pressure near the injection site induces stress changes even far away from the site of injection due to poroelastic coupling in rocks. The risk of induced seismicity was then analyzed through simulation of fault slip potential in the field. FSP analysis suggests orientation of faults along with proximity to injection site are key parameters influencing fault stability in the Ankleshwar field.