EPSRC DLA: Pump it up? Quantifying the integrity, capacity and risks of injecting CO2 into depleted gas fields

One full scholarship is available in the School of Earth and Environment in 2026/27. This scholarship is open to UK applicants and covers fees plus maintenance.<br /> <br /> The School of Earth and Environment invites applications from prospective postgraduate researchers who wish to commence study for a PhD in the academic year 2026/27 for the School of Earth and Environment EPSRC Scholarship. <br /> <br /> In this exciting project, the student will work at the forefront of the Energy Transition. As plans accelerate towards injecting carbon dioxide into depleted gas fields around the UK, all stakeholders need to have confidence in the process. In particular, we need to ensure both the mechanical stability of the reservoir over time and the immediate safety of drilling new injection wells.

<div><strong>Background & Rationale:</strong> You will tackle this problem with an integrated programme of data science, laboratory rock deformation experiments and numerical modelling. The results from this project will inform policy at national and local levels. Depleted gas fields comprise some of the main targets for carbon dioxide storage projects, in the UK and overseas. We know that production of oil, gas and water over time changes the effective stress in a reservoir, and likely therefore the total stresses in the reservoir and overburden. These changes in stress may involve pore pressure-stress coupling where the minimum horizontal stress decreases as a proportion of the reservoir pressure; but equally, they may not. Either way, the present-day effective stress in these depleted fields is different to when production started, and will change again on injection of carbon dioxide. Injection of carbon dioxide will raise the reservoir pressure, reduce the effective stress and possibly change the total stress in the reservoir and the surrounding rocks. Several such schemes are scheduled to start around the UK in the next few years, but published data to support the forecasted response of the reservoirs are hard to find.</div> <div> </div> <div><strong>Hypothesis:</strong> To ensure the integrity of any proposed storage scheme, we need to reliably predict how the effective and total stresses will change on injection; and to enable safe and cost-effective drilling, we need to constrain the present day fracture gradient. Pore pressure-stress coupling is well described, although not necessarily well understood. Critically, there is no consensus in terms of the governing constitutive rheological model to explain observed reservoir behaviour during depletion. Limited laboratory experiments, numerical modelling and observations from oil and gas fields confirm that stress path hysteresis is possible, or even likely, on injection after depletion. This project will evaluate the hypothesis that pore pressure-stress coupling can be predicted based on careful laboratory measurements of porous rock behaviour at the appropriate physical conditions.</div> <div> </div> <div><strong>Aims & Objectives:</strong> Depending on their specific interests and experience to date, the student will aim to deliver: </div> <div><br /> •    Quantitative estimates of depleted reservoir stress paths in selected former gas fields; <br /> •    Constraints on the rheological behaviour of depleted reservoir rocks;  <br /> •    A tool to predict the geomechanical behaviour on carbon dioxide injection, including estimates of uncertainties in the current in situ and predicted future stress state;  <br /> •    Specific policy recommendations at national and local levels targeted at improving regulatory oversight and public confidence in the injection process. </div> <div> </div> <div><strong>Methods & Training:</strong> The student will integrate borehole and reservoir geomechanics, structural geology, experimental rock mechanics and data science. To quantify reservoir stress paths during depletion, we will use open data from public repositories and published industry papers. To provide constraints on the rheological behaviour of depleted reservoirs, we will integrate the data from the stress path estimation with targeted rock deformation experiments on selected rock samples from borehole core and outcrop analogues. These experiments will be conducted in the Geosolutions Leeds Geomechanics Laboratory using the Sanchez triaxial rock deformation apparatus (confining pressures up to 250 MPa, and temperatures up to 200°C). The student will measure stress-strain behaviour for poroelastic properties, pore volume changes, and P- and S-wave velocity variations under changing loads. By integrating the findings from the borehole geomechanical analysis and the laboratory deformation experiments, the student will develop a predictive numerical model in open source Python to predict future stress paths on injection. At all stages of the work, the student will be trained to estimate errors and constrain uncertainties in the measured and estimated variables.  Impact will be generated through collaboration with the North Sea Transition Authority at the national regulatory level, and operator companies at the local level.</div> <div> </div> <div>This project will benefit from the wider Geosolutions Leeds project portfolio, including ongoing research into geothermal energy, subsurface storage and critical minerals. Geosolutions Leeds is a core part of the University of Leeds Climate Plan, an ambitious £174M programme designed to decarbonise campus by 2030 and support the Energy Transition of the city and wider region. </div>

<p>Formal applications for research degree study should be made online through the <a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University's website</a>. Please state clearly in the research information section that the research degree you wish to be considered for is <em>ESPRC DLA: Pump it up? Quantifying the integrity, capacity and risks of injecting CO2 into depleted gas fields</em> as well as <a href="https://environment.leeds.ac.uk/see/staff/12746/dave-healy">Prof. Dave Healy</a> as your proposed supervisor.</p> <p>If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below).</p> <p><em>As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.</em></p>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

The minimum English language entry requirement for postgraduate research study in the School of Earth and Environment is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<p>We are offering a fully funded scholarship to study the project <em>Pump it up? Quantifying the integrity, capacity and risks of injecting CO2 into depleted gas fields</em>, at the School of Earth and Environment, University of Leeds for one UK status candidate. The funding covers UK tuition fees as well as a UKRI matched stipend (currently £20,780 in 2025/26) per year, subject to satisfactory progress.</p> <p>Eligibility Criteria</p> <p>Applicants must be eligible for UK (Home) fees/funding.</p> <p>If you are unsure whether you are eligible for UK fees/funding, please see our <a href="https://www.leeds.ac.uk/undergraduate-fees/doc/fee-assessment">fee assessment page.</a></p>

<p>For further information please contact the project supervisor, David Healy: <a href="mailto:D.Healy@leeds.ac.uk">D.Healy@leeds.ac.uk</a>.</p> <p>For application guidance please contact the Postgraduate Research Admissions Team: ENV-PGR@leeds.ac.uk</p> <p> </p>