Fault characterization (Utah); importance of geometry and composition for along-fault flow of CO2
The impacts of Carbon Capture and Storage (CCS) on mitigating climate change appear increasingly more important (Bui et al. 2018, doi.org/10.1039/C7EE02342A). Subsurface CO2 storage could be part of the mitigation. Accordingly, subsurface analysis of stratigraphic intervals selected for CCS project through the study of sedimentary systems cut by faults is of significant relevance.
This master project will offer you the chance to join a large multi-disciplinary team of international researchers working on one of these CO2 reservoir analogues, which crops out in Utah, USA. You will collaborate with scientists and students from Utah State University, Western Colorado University, Boise State University, and Colorado School of Mines.
The Middle to Upper Jurassic faulted and fractured stratigraphic interval in question has been accumulating CO2 naturally for at least the last 400’000 years. It is composed of a complex vertical and lateral arrangement of continental and shallow-marine seal and reservoir units that are cut by the Little Grand Wash Fault (LGWF). Your thesis will address this fault-based in several weeks of fieldwork. Another thesis on the local stratigraphy will contribute to the overall aims of the study. The results of your thesis and the other complimentary thesis will be implemented in an ultra-high-resolution, geological model of the area, in order to simulate the migration of CO2 through these faulted sedimentary units.
Aim of the thesis:
The aim is to establish a viable geological model for the LGWF and investigate controls on CO2 leak along the fault, by combining field data and published results.
Work scopes cover;
- characterising the LGWF in map view and by a series of detailed cross-sections,
- investigate fractures that have leaked CO2 in the past,
- investigate other exhumed faults that can help constrain the subsurface geometry of the LGWF, and
- Use detailed stratigraphic information to calculate shale gouge ratio (SGR) for the various strands of the LGWF.
- Contribute to constructing an ultra-high-resolution, a geological model of the faulted stratigraphic intervals that will inform work with subsurface CO2 storage sites in the North Sea basin.
Research method and dataset:
This thesis is field-based, requiring ca 3 weeks of fieldwork in Utah, in the vicinity of the Little Grand Wash Fault, south of Green River, Utah, USA (Fig. 1). You will consider sedimentary units in large lenses between segments of the LGWF, with the aim to constrain the fault zones’ map-view geometry and verify the stratigraphic offset on the fault for each segment. Some sites will be analysed for fractures, to further understand how fluids move up along the fault. In addition, several other sites with well-exposed faults will be visited, to acquire information on fault geometry that can be used for the subsurface part in detailed cross-section construction.
The student will:
- Get a unique experience in the field, collecting data surrounded by an amazing and pristine nature
- Learn how to conduct independent research, and develop his/her academic writing and presentation skills
Background for the project:
This MSc work is part of the COTEC research project at UiO focusing on CO2 containment and monitoring techniques. The student will get a chance to work in a cross-disciplinary team taking part in a collective effort on understanding how CO2 migrates through sedimentary strata, fractures and faults. Field campaigns for data collection in Utah are planned within the project and provide possibilities for the collection of additional data for this study.
Alvar Braathen and/or Valentin Zuchuat