The Department of Earth Sciences currently seeks a highly-motivated, high-potential applicant for a position as a PhD researcher in rock deformation at the High Pressure and Temperature Laboratory, in collaboration with the Structural Geology & Electron Microscopy Group. Globally, depleted oil and gas reservoirs represent huge potential storage volumes for CO2. However, Joule-Thomson cooling and freezing of any pore fluid, due to injection of high-pressure CO2 into a low-pressure, depleted reservoir, causes an important technical challenge. This could impact injectivity, but also near-well stability and well integrity. 
The current PhD position will focus on determining and quantifying the effects of re-pressurisation and pressure-temperature cycling on the mechanical and transport properties of sandstone reservoirs and clay-rich caprocks. The approach adopted will involve experimental deformation (uniaxial, triaxial, hydrostatic) conducted at in-situ reservoir conditions (sub-zero up to typical reservoir temperatures) and permeametry work. In addition, microstructural analysis using state-of-the-art (cryo) electron microscopy techniques will be performed on selected samples. Together with microphysical theory, the results will be used to develop quantitative, mechanism-based models describing the mechanical and transport behaviour of the materials, which are thus directly relevant to predicting the long-term integrity of a CO2 storage complex.
The first three years of the project are funded through an international Accelerating CCS Technologies (ACT) research programme Re-use of depleted oil and gas fields for CO2 sequestration (RETURN). Additional funding for a 4th year is also available, thus constituting a 4-year PhD position. Throughout the project, there will be regular interactions with other academics and industry partners in the RETURN programme. A personalised training programme will be set up, which will reflect the candidate's training needs and career objectives. As part of this training, up to 10% of the candidate's time will be dedicated to assisting in Bachelor's and Master's teaching programmes.

• Applicants must not have a PhD degree.
• Applicants must hold a Master's degree in geosciences, physics, or materials science (at the starting date of the contract), and must have good quantitative and programming skills as well as an interest in chemistry.
• Applicants must have experience of Earth materials research, ideally in rock or materials mechanics or in rock physics.
• Applicants must have excellent written and spoken English skills and be highly motivated to work in an international team.

You will be offered a temporary position (1.0 FTE), initially 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. The gross salary ranges between €2,443 in the first year and €3,122 in the fourth year of employment (scale P according to the Collective Labour Agreement Dutch Universities) per month for a full-time employment. Salaries are supplemented with a holiday bonus of 8% and a year-end bonus of 8.3% per year. In addition, Utrecht University offers excellent secondary conditions, including an attractive retirement scheme, (partly paid) parental leave and flexible employment conditions (multiple choice model). More information about working at Utrecht University can be found here.

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 societal themes. Our focus is on Dynamics of Youth, Institutions for Open Societies, Life Sciences and Sustainability.

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 45 scientists and more than 110 PhD students and postdoctoral researchers. Our research programme spans four intertwined themes: Climate & Life, Earth Interior, Earth Materials, and Environmental Earth Sciences. We house or have access to a wide variety of world-class laboratories.