PNNL

Abstract

Geological sequestration of CO2 is gaining acceptance as a potentially viable option to mitigate global climate change. Several field scale demonstration projects are currently under way. While several tools have been developed in the recent past for modeling the fate and transport of injected CO2 in the host formations, large scale implementation of this technology worldwide requires effective tools for risk and consequence assessment at field scale, design and implementation of technologies for monitoring and verification, as well as regulatory evaluation for permitting purposes. Fate and transport models can serve as an effective basis for developing such tools for a given site, in an integrated manner. In this paper, we have used a reservoir-scale numerical model and extended it further, to develop an integrated assessment framework which can address the risk and consequence assessment, monitoring networks design and permitting guidance needs. The modeling approach is ‘integrated’ in two senses: (i) modleing of the entire geosystem, which includes the host formation, overburedn including the vadose zone, the shallow sub-surface and the surface (air, soil and water) environments which are the ultimate risk receptors; (ii) use of the same underlying modeling framework to assess the fate and transport of injected CO2 and tracers, risk and consequence assessment and sensor-based monitoring network design. The method was used to simulate sequestration of CO2 in moderate quantities at the Ohio River Valley CO2 Storage Project, Mountaineer Power Plant, New Haven, West Virginia. The overall project is aimed at providing an understanding of the viability of carbon capture and storage as a global warming countermeasure by performing an integrated demonstra¬tion of carbon dioxide (CO2) capture and geologic sequestration at a meaningful scale. Such integrated approaches are valuable to project implementation, permitting, monitoring as well as site closure.