Successful operation of Enhanced Geothermal Systems (EGSs) requires easy flow of geothermal fluids. Pre-existing faults often provide low permeability pathways for fluid flow. However, such faults may be reactivated during geothermal operations, potentially leading to induced seismicity. Whether or not fault movement leads to induced seismicity depends on the fault frictional properties, which is affected by a range of factors, including the fault rock composition. Both permeability and frictional properties can be affected by the flow-through of the undersaturated solutions involved in geothermal operations, which can lead to mineral dissolution and precipitation, as such changing the (connected) porosity and the fault rock composition. This project aims to quantify how flow-through of undersaturated solutions affects the composition and transport properties of fault materials typical for EGSs, and what the implications are for the frictional properties and thus induced seismicity. The approach adopted involves experimental work, microstructural investigations and microphysical modelling. In addition, the student may be able to work with an industry reactive transport modelling code.
The project contributes to a better understanding of the processes active in EGSs, including fault frictional properties and induced seismicity. It is anticipated to result in experimental data on and model predictions of the evolution of fault rock composition and permeability during flow-through of geothermal fluids under a range of conditions with trends identified and quantified. These results can be used as input for studies addressing the evolution of the transport properties of typical fault rocks found in EGCs and the risk of induced seismicity in such systems. This project is directly linked to the successful NERC highlight Topics “Geothermal Power Generated from UK Granites (GWatt)” project, on which the primary supervisor is PI for HWU.
The PhD student will learn to: design an experimental program; perform rock deformation experiments; analyse data; perform microstructural analysis, use optical and electron microscopes; formulate microphysical and potentially numerical models; and write scientific papers. Finally, there may be the possibility for an internship with an industrial partner.
Informal enquiries should be directed to the primary supervisor, Dr Sabine den Hartog.
Applicants should have a first-class honours degree in a relevant subject or a 2.1 honours degree plus Masters (or equivalent). Scholarships will be awarded by competitive merit, taking into account the academic ability of the applicant.
Please complete our online application form. Please select PhD programme Petroleum Engineering, Petroleum Geoscience or Applied Geoscience within the application and include the project reference, title and supervisor names on your application. Applicants who do not include these details on their application may not be considered.
Please also provide a written proposal, at least one side of A4, outlining how you would approach the research project. You will also be required to upload a CV, a copy of your degree certificate and relevant transcripts and one academic reference. You must also provide proof of your ability in the English language (if English is not your mother tongue or if you have not already studied for a degree that was taught in English). We require an IELTS certificate showing an overall score of at least 6.5 with no component scoring less than 6.0 or a TOEFL certificate with a minimum score of 90 points.
Applicants MUST be available to start the course of study in October 2019.
Scholarships will cover tuition fees and provide an annual stipend of approximately £14,999 for the 36 month duration of the project.