Monitoring strategies for CO 2. Nick Riley Jonathan Pearce. Storage

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1 Monitoring strategies for CO 2 storage Nick Riley Jonathan Pearce

2 Outline of talk Why do we need to monitor CO 2? How & what do we monitor? Monitoring strategies Summary

3 EU CCS Directive Overriding consideration is: The purpose of environmentally safe geological storage of CO 2 is permanent containment of CO 2 in such a way as to prevent, where this is not possible, eliminate as far as possible negative effects any risk to the environment human health. site- "storage site" means a defined volume area within a geological formation used for the geological storage of CO 2 associated surface injection facilities Complex- storage complex" means the storage site surrounding geological domain which can have an effect on overall storage integrity security; that is, secondary containment formations; Leakage- "leakage" means any release of CO 2 from the storage complex dialogue

4 Why monitor? To demonstrate site performance. Verify in situ masses of CO 2 stored Underst processes Calibrate / test reservoir simulations Predict long-term site behaviour to enable transfer of site responsibility at site closure to Competent Authority Environmental reasons For climate change Provide early warning of leakage To assess local health, safety ecosystem impacts of leaks

5 Why monitor? To demonstrate site performance. To build public confidence, especially in early demonstrations Key question from public: Will it leak? Financial reasons Markets need confidence in technology. Any CO 2 emitted to the ocean or atmosphere from a storage site must be accounted for in National Allocation Plans within the European ETS, requiring quantified measurements.

6 Characterisation modelling monitoring risk assessment International Energy Agency Green House Gas Programme, Risk Assessment, CO 2 FEP database International Energy Agency Green House Gas Programme, CO 2 storage monitoring selection tool, v2.2.1/index.php dialogue

7 Monitoring aims A range of monitoring aims can therefore be recognised: Locating tracking the CO 2 plume at depth Demonstrating containment monitoring the top-seal Monitoring trapping mechanisms quantifying storage Verifying calibrating predictive models Monitoring potential leakage routes including Wellbore integrity Monitoring near-surface leakages, if any Monitoring for seismicity (indicator of fault reactivation) ground movements

8 Basic Geological Traps (Riley in press) dialogue

9 Amounts movement of CO 2 within storage reservoir immediate surroundings Deep monitoring Predictive models of site performance calibrated, tested & adjusted Early warning of migration of CO 2 to shallower depths Can be acquired at or near surface or in subsurface in wells (injection / monitoring)

10 Shallow monitoring Detect & quantify amounts of CO 2 that have migrated into the shallow overburden, the soil or seabed Or ultimately the ocean or atmosphere In addition to techniques that measure CO 2 concentrations in these locations, an evaluation of the impact on local ecosystems may be needed

11 Shallow focussed monitoring: coverage issues detected not detected sample points (map view) 3D seismic gives continuous areal coverage (laterally uniform detection capability) point coverage (non-uniform detection capability) dialogue

12 Selection of monitoring tools Location of site: Offshore/onshore Access (l use, topography, wells ) Volume to monitored (depth, footprint) Monitoring aims Timing Project stage (baseline, injection, post-injection, closure) Mass of CO2 injected (detection limits, plume migration) Cost benefits Environmental impacts of monitoring technologies

13 Selecting monitoring tools e.g. A generic offshore, depleted gas field High To be considered Rejected Multicomponent surface seismic Surface gravimetry 3D surface seismic 2D surface seismic Microseismic monitoring Seabottom EM Long-term downhole ph Vertical seismic profiling (VSP) Cost Downhole fluid chemistry Bubble stream chemistry Geophysical logs Boomer/Sparker High resolution profiling acoustic Cross-hole seismic imaging Downhole pressure/temperature Tracers Seawater chemistry Headspace gas Multibeam echo sounding Sidescan sonar Cross-hole EM Permanent borehole EM Well gravimetry Tiltmeters Cross-hole ERT Low To be included Bubble stream detection Ecosystems studies To be considered for mitigation? For building confidence? High Value/usefulness Low

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18 Monitoring strategies A strategy should comprise, inter alia Clear statement of aims Justification of selection of parameters, techniques, threshold values Frequency of monitoring Footprint of monitored area Record keeping reporting (internal, external) These will vary with the techniques used, parameters being monitored stage of project

19 Four basic stages 1. Pre-injection Site characterisation for licence to inject Baseline surveys 2. Injection Monitoring for trading Monitoring for local HSE 3. Post-injection Building confidence in predictive models Application for licence to close site 4. Post-transfer Undertaken by Competent Authority

20 1. Pre-injection Operator applies for a storage licence with an appraisal term: Site characterisation geological model Predictive model including reservoir simulation Environmental impact assessment Risk assessment Monitoring programme Remediation strategy

21 1. Pre-injection The appraisal terms are time-limited Non-intrusive exploration Intrusive characterisation, including injection tests For depleted gas fields appraisal terms may be 1-5 years For saline aquifers, appraisal exploration terms may be much longer. Site performance criteria defined as part of licence to inject. Baseline survey(s) will be needed prior to injection would be undertaken once a consent to store has been obtained Monitoring programme will be specific to each site.

22 Monitoring programmes Monitoring plans submitted as part of the Application for consent to inject: Plans need to consider: 3D volume footprint of baseline surveys (defined by site characterisation predictive modelling of plume behaviour) Appropriate technique selection Frequency of monitoring: depends on rate of injection, speed of plume migration, objectives, technique (continuous or repeat surveys) Use of monitoring wells Repeatability, accuracy, detection limits Costs, usefulness, risks potential impacts

23 2. Injection Mass of CO 2 injected to be verified at regular intervals. History matching against predicted behaviour. If migration /or leakage occurred Monitoring would establish if site performance is still acceptable. Monitoring type frequency could be changed. Revision of storage capacities, project lifetime may be needed. Remediation may be necessary. Injection may need to be stopped.

24 3. Post-injection Operator applies for consent to close site Monitoring continues at a reduced level Infrastructure likely to be decommissioned at end of injection so access to wells may no longer be possible. EC Directive suggests duration of up to 20 years with Member S tate discretion Transfer of responsibility for site to Competent Authority Evidence that (revised) site performance is acceptable against pre-defined criteria. Long-term risk assessment is acceptable. Competent Authority may wish to continue monitoring will developing a financial mechanism to fund this.

25 4. Post-transfer No monitoring should be required The safety case for a storage site should be based on the fundamental principle that there will be no requirement for future generations to demonstrate the site s safety. 1 Therefore no storage site should be closed unless the long-term safety can be assured. It follows therefore that long-term post-closure monitoring should not be needed. 1 Stenhouse et al., 2004.

26 4. Post-closure However, arguments for post-closure monitoring are: To demonstrate no fugitive emissions (leaks) to avoid loss of credits, at least during the lifetime of the ETS. To provide assurance that site integrity is maintained. Confirmation of (some) safety assessment predictions. Public confidence, especially in early demonstration storage projects.

27 Monitoring process Site characterisation for a proposal to inject Geological model Predictive model & reservoir simulation Environmental Impact Assessment Risk assessment Remediation strategy Operator applies to regulator for site licence to inject expert QC review of application Approved Site licence awarded Acquire baseline monitor surveys Commence injection Revise storage estimates, project lifetime monitoring programme Licence renewal for next 5-year ETS accounting period No No Yes Increase monitoring frequency More monitoring Remediate if necessary Yes Is leakage occurring or likely to occur? Yes Is migration occurring or likely to occur? Revise predictive models No review. Is system behaving as expected, within pre-defined tolerances? Monitoring predictive performance modelling Yes injection complete Yes Is site performance acceptable against performance cirteria? No Stop injection Monitoring for Risk assessment Accounting Local HSE Operator provides evidence that system will behave as original (or revised) Expectations application unsatisfactory Expert QC review of application Regulator issues abonment certificate assumes liability Site closure Remediation No years Is predicted site performance acceptable against performance criteria? Yes Notice of site Closure KEY Key events in monitoring process Times when monitoring may be necessary Major decision points which monitoring might influence

28 Summary Monitoring will be required for a variety of reasons to provide confidence in the safety of CO 2 storage. Monitoring of the injected CO 2 has been shown to be technically feasible in a number of demonstration research projects. Lots of mature technologies are available. An online tool is available to help non-specialists consider appropriate monitoring techniques. Newer techniques are being developed tested by researchers internationally. See

29 Fossil Fuel Emission (GtC y -1 ) (From Greenpeace False Hope ) (1 Pg = 1 billion tons or 1000 x million tons) Carbon Dioxide Information Analysis Center International Energy Agency A1B A1FI A1T A2 B1 B2 CO 2 emissions (PgC y -1 ) Gas Oil Cement Coal 40% 36% Le Quéré et al., Nature-geoscience