The Gas Monitoring Facility provides equipment for the field measurement of gases in the near surface environment. The main focus of current research is on monitoring for leakage and the impacts of leakage from the geological storage of carbon dioxide (CO₂). Research has also been carried out on radon, landfill gases, volcanic gases and for geothermal studies. The facility provides equipment for measuring concentrations of a range of gases in both the soil and the atmosphere and for determining the flux of gases across the soil/air boundary.

Background

Measurement of radon in soil gas was used in exploration for uranium from the 1960s, with equipment being developed in conjunction with Harwell. Radon, as well as CO₂ and other gases, was used in exploration for other minerals in subsequent decades. More recently radon in soil gas has been used to assess indoor radon hazard, radiation dose to wildlife and as a more general tracer gas to identify fluid migration pathways and mechanisms.

Within the last decade near surface gas measurements have formed an important part of monitoring for carbon capture and storage projects and have been used on projects worldwide. This has involved research at sites of natural CO₂ seepage in Italy, Germany and Greece, the Weyburn project in Canada, In Salah in Algeria and experimental injection facilities in the UK (ASGARD) and Norway (CO₂ Field Lab). Observations have also been made at UK landfill sites. Projects include the EU Weyburn project, In Salah Gas Joint Industry Project, CO₂GeoNet, CO₂ReMoVe, CO₂ Field Lab and RISCS. This has involved both national and international collaboration in particular with European and North American colleagues.

Capabilities

• Soil gas sampling and analysis for CO₂, oxygen (O₂), methane (CH₄), carbon monoxide (CO), hydrogen sulphide (H₂S), radon (Rn), hydrocarbons
• soil gas flux measurement for CO₂ and CH₄
• atmospheric measurement of near-ground CO₂ and CH₄ using mobile open path lasers
• continuous monitoring of CO₂, CH₄, temperature and pressure using buried or surface mounted probes with remote data access
• continuous monitoring of CO₂ flux by automatic accumulation chamber and eddy covariance techniques

Approaches in CO₂ storage research

• observing natural background variations of near surface gases to define baseline conditions prior to CO₂ injection
• observing the changes in gas concentrations and fluxes arising from controlled or natural leakage of CO₂. This helps in defining criteria to recognise leakage at CO₂ storage sites and in assessing the detection capabilities of different types of equipment
• drawing up monitoring strategies for generic and actual storage sites
• quantifying leakage for emissions trading purposes

The detection and quantification of CO₂ leakage are required under developing legislation as defined, for example, by EU Directives.

Contacts

Please contact Dr Dave Jones for further information

• Carbon capture and storage (CCS)