Magnetotelluric characterisation and monitoring of the Hontomín CO2 storage site, Spain

The electromagnetic methods are especially interesting for the characterisation and monitoring of geological storage of CO2 sites. The electrical resistivity is a physical parameter that depends on the mineralogical composition of the rocks, as well as on other characteristics such as porosity, pore...

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Detalles Bibliográficos
Autor: Ogaya Garcia, Xènia
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2014
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/284957
Acceso en línea:http://hdl.handle.net/10803/284957
Access Level:acceso abierto
Palabra clave:Prospecció magnetotel·lúrica
Prospección magnetotelúrica
Magnetotelluric prospecting
Captura i emmagatzematge de diòxid de carboni
Captura y almacenamiento de dióxido de carbono
Carbon sequestration
Ciències Experimentals i Matemàtiques
55
Descripción
Sumario:The electromagnetic methods are especially interesting for the characterisation and monitoring of geological storage of CO2 sites. The electrical resistivity is a physical parameter that depends on the mineralogical composition of the rocks, as well as on other characteristics such as porosity, pore connectivity, pore fluid salinity, saturation, temperature and pressure. The CO2 injected in the reservoir produce changes in the resistivity that enables its detection with electromagnetic methods. However, it is necessary to have a thorough knowledge of the structure at the pre-injection state to detect and quantify the changes produced by the injected CO2. The magnetotelluric method is the only electromagnetic method with a penetration depth ranging from ten of metres to hundreds of kilometres depth. Furthermore, this method allows determining the directionality and evolution of the structures in depth thanks to its tensorial character. Hence, the objective of this thesis is to characterise using the magnetotelluric method, the Technological Development Plant (TDP) of Hontomín for Geological Storage of CO2 in a deep saline formation and evaluate the capabilities of the magnetotelluric method to monitor the injected gas. The work presented in this thesis represents an important contribution to the characterisation projects of CO2 storage sites in deep saline formations. The 3D resistivity model obtained defines the reference geoelectrical model for the subsequent electromagnetic monitoring studies. Moreover, the model shows the dome structure of Hontomín and the main fault system. The model allows identifying the potential leakage zones and defines the monitoring needs for the Hontomín TDP. This model also correlates satisfactorily with hydrogeochemical, seismic, gravimetric and well-log data. Additionally, the monitoring capabilities of the magnetotelluric method have been assessed in this work, proposing a new methodology to improve the resolution of the surface magnetotelluric responses to resistivity changes occurred at the reservoir level.