May 2013

National Risk Assessment Partnership - A Strategy to Manage CO2 Emissions

The National Risk Assessment Partnership is one of several modeling and simulation efforts conducted under the DOE Office of Fossil Energy's Carbon Capture and Storage Simulation Initiative. Carbon utilization and storage—the injection of carbon dioxide (CO2) into permanent underground and terrestrial storage sites—is an important part of our nation's strategy for managing CO2 emissions. 

An illustration of carbon storage system in a geological cutaway.
An illustration of carbon storage system in a geological cutaway.

This partnership is led by NETL and the NETL-Regional University Alliance (RUA) and involves four other DOE national laboratories: Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, and Pacific Northwest National Laboratory. This multi-lab effort leverages broad technical capabilities across the DOE complex to develop an integrated science base that can be applied to risk assessment for long-term storage of CO2.

The basic goals of NRAP are to: 

  • build a suite of science-based tools for predicting the performance of CO2 storage sites, 

  • apply the tools to a range of potential scenarios to clarify key storage-security relationships, and 

  • develop a suite of monitoring and mitigation protocols that can be used as part of a risk management strategy. 

The overall NRAP effort is divided into four general technical components, plus an additional component that captures issues with large stationary sources other than power plants. 

Phase I of NRAP comprises (1) development of a methodology and computational platform for quantifying risk profiles based on integrated assessment models (IAMs) and Uncertainty Quantification (UQ) and (2) targeted scientific investigations at the laboratory and field scale to validate/calibrate models and reduce uncertainties in the predicted risk profiles.

Phase II is ongoing and runs to fiscal year 2015. This phase focuses on identifying and developing risk management approaches including strategic monitoring to verify system performance and lower uncertainty. This includes field-scale processes testing to validate predicted behaviors of natural systems.

Phase III, if needed, involves data collection from a field site/s for model validation and testing.

CT image of fracture. Experiments performed by NRAP show that chemical and mechanical processes can lead to natural sealing of wellbore leakage pathways over time.
CT image of fracture. Experiments performed by NRAP show that chemical and mechanical processes can lead to natural sealing of wellbore leakage pathways over time.

NRAP's approach to modeling leakage scenarios is to develop software in three stages, each building on information from the previous stages. In the first stage, detailed component models are developed and used to generate reduced-order models (ROMs) that are combined into a single IAM applicable to a limited number of sites. ROMs and IAMs developed in the second stage have improved efficiency. Additionally, the capabilities of ROMs have been expanded, corresponding to different types of storage conditions. The third stage will involve additional capabilities for a broader range of sites and heightened model efficiencies, with calibration and verification of model components and model integration.

This program also uses a staged approach to developing tools for induced seismicity risks. The first stage is to build an integrated model capable of generating a probabilistic seismic hazards assessment for induced events at a single fault. Additional stages expand this capability to multiple faults and to basin scale simulations. 

NRAP's Phase I products include six reports that form a partial basis for the risk assessment framework. These reports are available here. The report titled, "Quantification of Risk Profiles for Atmosphere and Groundwater," is a good example of how the five NRAP labs come together to produce useful results. The report summarizes NRAP efforts to develop an approach to generate quantitative risk profiles for release of CO2 to the atmosphere at a CO2 storage site using a science-based prediction approach.

 
 
  


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