Fracture characterization and monitoring of underground CO2 storage
This project was assigned to the student Stine Grindheim when she started her Master's program in Earth Sciences, Geophysics, in the Autumn semester 2022.
Underground CO2 storage has been proposed to mitigate climate change caused by increased levels of CO2 in the atmosphere. This CO2 storage is currently being tested at a few sites such as Sleipner and more, larger sites, have been proposed at Smeiheia and Aurora. However, in order for CO2 storage to be successful, it is important to make sure that that the CO2 does not leak through the caprock. This is typically done using seismic imaging and time-lapse seismics.
Hypothesis (scientific problem):
Monitoring of CO2 storage in a large number of very different subsurface reservoirs requires accurate and flexible seismic monitoring techniques. Seismic monitoring has been relatively successful. For example, time-lapse seismics makes it possible to detect saturation changes in the reservoir. However, there are still important issues to be resolved. Monitoring of flow through (near) vertical fractures and faults, to name one such issue, is still quite difficult. The challenges here are both the narrow width as well as the steepness of the faults. It is therefore important to improve seismic characterization of fault zones.
In this project acoustic and elastic forward modeling and imaging/inversion methods will be used to better characterize fault zones. The project consists of three parts. The first part of the project consists of building velocity models that contain realistic fault zones (e.g. based on what is observed in outcrops). These velocity models will be both based on a regular as well as an irregular grid. In the first instance the modeling will be acoustic. Later on also (visco-)elastic models will be used. The second part of the project consists of using both imaging and full waveform inversion to invert for detailed fault zone properties. In the third and final part of the project, if time allows, the developed methodology will be applied to a time-lapse scenario for one of the proposed CO2 storage sites (e.g. Smeaheia or
Proposed course plan during the master's degree (60 ECTS):
GEOV274 (10 sp)
GEOV277 (10 sp)
GEOV300 (5 sp)
EU field course in Kiel (5sp)
GEOV352 (5 sp)
AG335 (10sp) (UNIS, Svalbard)
AG349 (5sp) (UNIS, Svalbard)