PhD: Experimentation on Fluid-injection Induced Seismicity in Geothermal Systems

The Department of Earth Sciences is looking for a highly motivated candidate for a PhD position at its High Pressure and Temperature Laboratory (HPT), run by the Experimental Rock Deformation Group.

Your job
Geothermal energy, as a sustainable source with a small land footprint, is increasingly playing a crucial role in the energy transition. In the Netherlands and Europe, there is growing interest in tapping into deep fractured reservoirs to exploit high enthalpy geothermal resources.

Sustainable geothermal operations in deep fractured reservoirs require sustained reservoir circulation, thermal longevity, and minimal seismic risk, all of which are closely linked to the connectivity of the fracture system. However, the high pressure resulting from re-injected fluid can cause fracture slip, significantly altering the connectivity and hydraulic conductivity of the fracture systems, potentially leading to induced seismicity. To ensure sustainable geothermal operations, it is essential to understand how fractures behave under in-situ geothermal conditions, how they impact the connectivity and hydraulic properties of fracture systems, and how to mitigate seismogenic fracture slip. This PhD project is part of the NWO-funded GeoFirst project, which aims to advance sustainable geothermal exploitation and enhance seismic hazard management. This PhD project will involve close collaboration with geothermal energy operators, research and monitoring institutes, and geothermal industry associations.

Within this PhD project, you will perform rock mechanical and frictional experiments to characterise mechanical, frictional and hydrological properties of rock fractures in representative geothermal environments. You will also investigate fluid injection-induced fracture slip behaviour, and identify key controlling parameters with the support of analytical techniques. This will provide the foundation for developing friction-stability-permeability relationships for use in numerical modelling within a companion PhD candidate. Through collaborative experimental and numerical efforts, you will contribute to the development of a sustainable geothermal operation strategy. Throughout the project, you will regularly interact with the other consortium partners and present your results to a broader audience.

A personalised training programme will be set up, reflecting your training needs and career objectives. About 20% of your time will be dedicated to this training component, which includes following courses/workshops as well as training on the job in assisting in the Bachelor’s and Master’s programmes of the department at Utrecht University.

We are looking for a candidate in experimentation on fluid-injection induced seismicity in geothermal systems. You must have completed your MSc degree in Geomechanics, Hydrogeology, Geological engineering, Civil Engineering, Reservoir Engineering, or a related discipline by the time the position starts. Preferably, you will also have:

• experience or strong interest in rock mechanical experiments, or high-pressure and/or high-temperature laboratory experiments;
• experience or strong interest in analytical analyses (e.g., microstructural analyses, SEM-EDX, fluid chemistry);
• strong quantitative and data analysis skills;
• the ability to work independently and as part of a team in a multidisciplinary research environment;
• enthusiasm for geo-energy and applications relevant to the sustainable use of the subsurface; and
• excellent communication and interpersonal skills.

Due to the international character of our research, good command of spoken and written English is essential. We highly encourage applicants from all members of our community and of diverse backgrounds to join us.

We offer:

• a position for one year, with an extension to a total of four years upon a successful assessment in the first year, and with the specific intent that it results in a doctorate within this period;
• a working week of 38 hours and a gross monthly salary between €2,901 and €3,707 in the case of full-time employment (salary scale P under the Collective Labour Agreement for Dutch Universities (CAO NU));
• 8% holiday pay and 8.3% year-end bonus;
• a pension scheme, partially paid parental leave and flexible terms of employment based on the CAO NU.

In addition to the terms of employment laid down in the CAO NU, Utrecht University has a number of schemes and facilities of its own for employees. This includes schemes facilitating professional development, leave schemes and schemes for sports and cultural activities, as well as discounts on software and other IT products. We also offer access to additional employee benefits through our Terms of Employment Options Model. In this way, we encourage our employees to continue to invest in their growth. For more information, please visit Working at Utrecht University.

A better future for everyone. This ambition motivates our scientists in executing their leading research and inspiring teaching. At Utrecht University, the various disciplines collaborate intensively towards major strategic themes. Our focus is on Dynamics of Youth, Institutions for Open Societies, Life Sciences and Pathways to Sustainability. Sharing science, shaping tomorrow.

Utrecht University’s Faculty of Geosciences studies the Earth: from the Earth’s core to its surface, including man’s spatial and material utilisation of the Earth – always with a focus on sustainability and innovation. With 3,400 students (BSc and MSc) and 720 staff, the faculty is a strong and challenging organisation. The Faculty of Geosciences is organised in four Departments: Earth Sciences, Human Geography & Spatial Planning, Physical Geography, and Sustainable Development.

The Department of Earth Sciences conducts teaching and research across the full range of the solid Earth and environmental Earth sciences, with activities in almost all areas of geology, geochemistry, geophysics, biogeology and hydrogeology. The department hosts a highly international tenured staff of over 50 scientists and more than 110 PhD candidates and postdoctoral researchers. We house or have access to a wide variety of world-class laboratories, among which are the Electron Microscopy Centre, the Geolab, and the Earth Simulation Lab.

The department and its facilities are located at Utrecht Science Park. Utrecht is the fourth largest city in the Netherlands with a population of nearly 360,000 and forms a hub in the middle of the country. Its historical city centre and its modern central station can easily be reached from the Science Park by public transport or by a 15-minute bicycle ride. Utrecht boasts beautiful canals with extraordinary wharf cellars housing cafés and terraces by the water, as well as a broad variety of shops and boutiques.

For more information, please contact Dr Wenzhuo Cao at w.cao2@uu.nl, Dr André Niemeijer at a.r.niemeijer@uu.nl, or Dr Loes Buijze at loes.buijze@tno.nl.

Note that international candidates that need a visa/work permit for the Netherlands require at least four months processing time after selection and acceptance. This will be arranged with help of the International Service Desk (ISD) of our university. Finding appropriate housing in or near Utrecht is your own responsibility, but the ISD may be able to advise you therewith. In case of general questions about working and living in The Netherlands, please consult the Dutch Mobility Portal.

Candidates for this vacancy will be recruited by Utrecht University. Commercial response to this ad is not appreciated.

As Utrecht University, we want to be a home for everyone. We value staff with diverse backgrounds, perspectives and identities, including cultural, religious or ethnic background, gender, sexual orientation, disability or age. We strive to create a safe and inclusive environment in which everyone can flourish and contribute.

You can only apply via our online procedure using the 'apply now' button. E-mail applications cannot be accepted. Include the following information in your application:

• your curriculum vitae, including any courses taken that are relevant for the position;
• academic credentials (mark sheets and degree statements);
• your motivation letter.

No reference letters need to be submitted in your initial application. If you are shortlisted, we will contact you for referees. We aim for a quick selection procedure after the application deadline. The preferable starting date is 1 September and no later than 1 October 2025.