State-of-the-Art of Monitoring Methods to evaluate Storage Site Performance

 
1. INTRODUCTION
 
2. MONITORING TECHNIQUES
 
3. MONITORING CONCEPTS – STATUS QUO
 
4. SETTING UP A SITE-SPECIFIC MONITORING PLAN
 
5. CONCLUSIONS AND RECOMMENDATIONS
 
6. REFERENCES
 
 
» 3.1 General concepts and proposed monitoring guidelines
 
3.2 Regulations in place
 
3.3 Monitoring in selected current CO2 storage projects
 
 

3.1 General concepts and proposed monitoring guidelines

General monitoring concepts provide a high-level framework for setting up site-specific monitoring plans and give general recommendations for potentially suitable techniques (v. Goerne et al., 2010). General concepts often comprise a selection of methods that have been classified according to different criteria such as:

  • parameters to be measured,
  • physico-chemical processes,
  • monitoring purposes,
  • leakage pathways,
  • subjects of protection,
  • monitoring intensity and duration,
  • compartments: reservoir, caprock, surface ‑ (migration, leakage, seepage),
  • project phases,
  • applicability of methods,
  • marine / terrestrial setting,
  • resolution of methods,
  • normal operation (basic monitoring) and irregularities (supplementary monitoring).

According to v. Goerne et al., 2010 most published monitoring concepts focus on addressing and meeting the risk of increased CO2 concentrations in case of CO2 leakage to the surface and its impacts on near-surface ecosystems (e.g. Benson and Myer 2002; Pearce et al. 2005), i.e. focussing on HSE monitoring. Benson, 2006 discusses the possibilities and limitations of monitoring methods for ets monitoring. In the following, examples of published general concepts will be briefly summarised following v. Goerne et al., 2010.

  • Benson and Myer 2002 and Benson, 2006 propose methods for the monitoring of different "parameters" including physico-chemical parameters and processes considering various monitoring purposes, leakage pathways and subjects of protection.
  • Similarly to Benson and Myer, 2002, Chalaturnyk and Gunter, 2005 assign monitoring methods to different subjects of protection, leakage pathways, parameters and monitoring purposes. In addition, they suggest following the movement of the CO2 plume with time and distinguish migration (migration of CO2 within the storage reservoir), leakage (migration of CO2 out of storage reservoir) and seepage (CO2 emanation at surface).
  • Pearce et al., 2005 differentiate various monitoring purposes in the different project phases. They point out that the area to be monitored is usually larger than the areal extent of the CO2 plume, because the area of the pressure footprint and potential brine displacement also needs to be monitored. Based on a discussion of characteristics and the suitability of individual techniques for monitoring of the underground, criteria are derived for site-specific selection of appropriate monitoring methods. The BGS concept provides the basis for the monitoring-selection-tool, a web application available on the IEA GHG R&D programme's website (http://www.IEAghg.org).
  • The concept of Benson, 2006 considers different system components (compartments) from the storage reservoir to the atmosphere and differentiates terrestrial and marine environments. In the concept the most advanced technology and alternative methods for the different system compartments are selected based on the resolution potential of each technology.
  • Benson, 2007 distinguishes different project phases and suggests basic sets of methods for the preparation, operation and closure of a storage site: These basic sets contain suitable monitoring methods for normal operation that are supplemented by additional methods in case of irregularities.
  • Srivastava et al. 2009 assigned different monitoring techniques to the compartments atmosphere, near-surface environment and subsurface. For definition of monitoring tasks they consider operation and closure of the storage site as well as time spans before and after these, respectively.
  • A comprehensive overview of various monitoring techniques, their applicability and limitations can be found in IEA GHG, 2012. High-level guidance on monitoring can be found in the following international legal and regulatory frameworks:
  • IPCC, 2006 Guidelines for National Greenhouse Gas Inventories; these consist of a number of steps leading to the inventory and quantification of emission terms during injection and storage of CO2 for national greenhouse gas inventories;
  • OSPAR, 2007, Guidelines for Risk Assessment and Management of Storage of CO2 Streams in Geological Formations, which are only applicable for offshore areas, and
  • Guidance Document 2 (2011) "Implementation of Directive 2009/31/EC on the Geological Storage of Carbon Dioxide. Characterisation of the Sstorage Complex, CO2 Stream Composition, Monitoring and Corrective measures."
 

in depth

3.1.1 Monitoring guidelines according to EU CCS Directive and related Guidance Documents

According to the EU CCS Directive monitoring is essential to assess: whether injected CO2 is behaving as expected, w...

3.1.2 Integration of EU ETS monitoring and reporting guidelines

The Monitoring and Reporting Guidelines (MRG) under the EU ETS Directive (Commission Decision 2007/589/EC and its amendm...