"PhD: Unravelling Clogging Mechanisms in Porous and Fractured Rocks"

Job Description

In the energy transition many technologies rely on the injection and extraction of energy carriers, like geothermal heat, CO2 and hydrogen. Repeated fluid pumping could lead to clogging of fluid pathways. Are you ready to dive into the how, using cutting-edge imaging techniques?

Then the Department of Earth Sciences is looking for you! We would welcome a highly motivated and ambitious applicant for a PhD position to contribute to our research theme Sustainable Use of the Subsurface.

Your job

Clogging in geological formations poses critical challenges for subsurface applications from geothermal energy to CO₂ and hydrogen storage. While individual clogging mechanisms have been studied extensively, the dynamic interplay between physical particle deposition, chemical precipitation, and deformation-induced particle remobilisation remains poorly understood. These processes vary fundamentally across rock types – from porous sedimentary to fractured crystalline systems, with volcanic and altered crystalline rocks presenting unique intermediate cases. Recent advances in operando micro-computed tomography (µCT) enable unprecedented real-time visualisation of these processes, yet systematic investigation across diverse rock types and integration with predictive models remains lacking.

In this PhD study, you will be performing experiments and numerical simulations to understand and predict the clogging evolution in a range of geological media by:

• Quantifying physical and chemical clogging dynamics across a spectrum of rock types (porous sedimentary, porous volcanic, altered crystalline, and fractured crystalline rocks) using 4D µCT imaging
• Establishing the role of deformation in particle remobilisation and preferential flow path creation that controls clogging patterns
• Developing predictive digital rock physics and permeability evolution models from µCT data using machine learning and computational tools (PuMA/CHFEM/MOOSE) validated against experimental observations
• Bridging scales from pore-level processes (µm) to sample-scale behaviour (cm) through integrated experimental-numerical approaches

To achieve this, you will be doing in-situ experiments using our state-of-the-art in-house Zeiss Versa 610 µCT-scanner equipped with custom flow-through cells to capture clogging evolution. In addition, we will apply for beamtime at a synchrotron facility across Europe for critical experiments requiring very high imaging rates or ultra-high resolution. These experiments will be coupled with large- and small-scale flow-through experiments, using capabilities available at the High Pressure and Temperature Laboratory (in collaboration with Dr Suzanne Hangx) and the Porous Media Lab (in collaboration with Dr Amir Raoof) at the Department of Earth Sciences, to examine particle mobilisation thresholds, and how stress-induced deformation remobilises particles, creates new flow pathways, and redistributes clogging zones. Your experimental data and observations will be used to upscale from pore-scale physics to continuum behaviour.

If you are thrilled to dive deep into the world of real-time imaging for sustainable energy solutions, this is a great opportunity for you! This position offers you the chance to explore your passion for understanding the impact of subsurface activities and boost your career with high-impact research in a field that is rapidly growing.

The main supervisor of the study is Dr Roberto Rizzo.

Training

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 and/or workshops (some of which are mandatory), as well as training on the job in assisting in the bachelor’s and master’s degrees programmes of the department at Utrecht University. Through interactions with the various scientists and stakeholders, you will be exposed to potential career paths in both academia and industry, helping you guide your future.

Requirements

The successful applicant will hold an MSc in Earth Sciences, Geology, Physics, or related field by the time the position starts. Good quantitative skills and programming experience (Python/MATLAB/Julia) are essential. Ideally, you will have experience with acquisition and processing of tomographic images, rock mechanics, machine learning and/or numerical modelling.

Given the highly diverse nature of the research groups that you will be working with, excellent communication (written and spoken English) and interpersonal skills are essential. In return, you will be part of an international team in an inspiring environment.

If you already have a PhD degree, then we unfortunately cannot consider you for this position.

Do you feel that you are a good match for the position but feel you do not meet all of our requirements, or have questions regarding the skills you may need? Then get in touch with us, so we can explore how you potentially can learn and grow in this position.

Conditions of Employment

We offer:

• a position (1.0 FTE) for 1 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 36 - 40 hours and a gross monthly salary between € 3.059 and €3.881 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 also offers a range of its own schemes for employees. This includes arrangements for professional development, various types of leave, and options for sports and cultural activities. You can also tailor your employment conditions through our Terms of Employment Options Model. In this way, we encourage you to keep investing in your personal and professional development. For more information, please visit Working at Utrecht University.