09.35 Task 1: Overall monitoring objectives. Andy Chadwick, BGS (10 mins) 1

Task 1 Overall monitoring objectives Scene setting for technical work Overall aims and context of monitoring for offshore CO 2 storage projects: Monitoring for Containment Assurance: Monitoring for Conformance Verification: Contingency element Emissions Measurement (effectiveness of current technologies to detect and quantify CO 2 emissions at the seabed and in the water column). 2

Overall monitoring objectives Key regulatory and technical requirements for offshore CO 2 storage: Regulatory framework is most mature for NW Europe Sleipner (Norwegian North Sea) and Snøhvit (Norwegian Barents Sea) predate the current legislation. Goldeneye (UK North Sea), White Rose (UK North Sea) and ROAD (Netherlands North Sea) projects will be subject to European storage regs. 3 Task 1

Regulations reviewed OSPAR Guidelines (OSPAR 2007) European Storage Directive (EC 2009) EU Monitoring and Reporting Guidelines (MRG 2009) deal with the accounting of leaked emissions from storage sites under the EU Emissions Trading Scheme (ETS). Jonathan to add about London Protocol 2012, Australia and Japan although that hasn’t been included in this section (yet). 4 Task 1

Regulatory requirements (summary) Monitoring should be used to: 1.Demonstrate that a storage site is currently performing effectively and safely 2.Ensure that it continues to do so 3.Provide information supporting robust prediction of future performance Can be distilled into two main monitoring objectives: Containment assurance Conformance assurance Contingency monitoring (in the event that containment and/or conformance requirements are not met). 5 Task 1

Key monitoring actions for offshore storage required under the European regulatory framework 6 Task 1

Containment assurance To demonstrate that the stored CO 2 is securely retained within the storage site such that : it presents no hazard to health or the environment the greenhouse gas mitigation objectives of the storage are met. Deep-focussed unexpected migration of CO 2 out of the primary storage reservoir subsequent migration into the overburden and possible secondary reservoirs and movement out of the Storage Complex triggering the onset of leakage. early warning is given of potential movement of CO 2 to the seabed. Shallow-focussed detect CO 2 emissions changes of the seabed physical (bubbles) or chemical changes in the seawater column. displaced, fluids escaping from the storage site. 7

Conformance assurance The second element of proving storage performance is to show that storage processes at the site are understood with a sufficient level of certainty to preclude the possibility of significant future deviation from expected storage behaviour. The basis of this is conformance: a measure of the agreement between modelled predicted simulations of site behaviour and observed site behaviour. models and observations agree within acceptable limits enables the testing and calibrating of models of current site behaviour basis for reliable prediction of future site behaviour, long-term secure storage and satisfactory site closure Deep-focussed imaging and characterising processes in reservoir. resolution, sensitivity quantitative capability Non-conformance is where observed site behaviour deviates significantly from predicted, for example, falling outside the stated uncertainty ranges. 8

Contingency monitoring Assurance monitoring has detected significant deviation from planned performance Additional monitoring track the deviation assess possible consequences design corrective measures and verify efficacy ……… CO 2 is observed to be migrating into the shallower geological section, with a threat of future emissions. Contingency monitoring would be necessary to track the migrating CO 2 in the shallow subsurface, to assure that no emissions reach the water column and, if they did, to quantify them. 9

Offshore issues For large-scale offshore storage, the monitoring system will be focussed directly on a limited number of performance measures which are necessary and sufficient to demonstrate containment and conformance. A typical set of performance measures might comprise: Reservoir: spatial and temporal plume development (conformance and lateral containment) Reservoir: pressure evolution (conformance and containment) Overburden: spatial migration/leakage detection (vertical containment) Seabed and water-column: emissions detection and characterisation (vertical containment) 10 Task 1

Offshore logistics Determines the type of monitoring technologies that can be utilised Impacts on the design, implementation and efficacy of monitoring systems Factors: Water depths: logistics and the nature of CO 2 emissions in the water column.. Water movement: Disturbance of the water column will determine the rate at which fluids dissipate. Seabed type: Controls upward migration style - diffuse, episodic (pockmarks) or focussed flow (fractures) Seabed renewal rate: Determines reliability (and frequency) of time-lapse surveys to detect leakage-induced changes Anthropogenic effects: Trawling activity could destroy leakage-induced changes or monitoring equipment. Windfarm sea bed infrastructure could complicate coverage and quality of seabed monitoring surveys. 11 Task 1