Novel approaches to the geological characterisation of chalk hard grounds in the North Sea

Applications are invited for a 3-year funded PhD studentship to commence in October 2019.

This PhD will be based in the School of Earth and Environmental Sciences and will be supervised by Professor Andy Gale, Dr Mike Fowler and Dr Paul Charles Reid of Aker BP.

This industrial PhD is funded by a 3-year bursary from Aker BP, and is available to UK and EU students only. The bursary covers tuition fees, an annual maintenance grant in line with the RCUK rate (£15,009 for 2019/20), researcher laboratory expenses of £4,000 per annum, travel and subsistence to and from Norway, travel and subsistence to and from Texas (field trip) and a placement opportunity with Aker BP.

The University of Portsmouth has been carrying out applied geoscience research for over 50 years and is an international leader in chalk biostratigraphy through Professor Andy Gale.

This project will utilise our state of the art in house equipment and expertise to characterise the nature, lateral and vertical extent, causes of, and predictability of hardening in levels of the Valhall and Hod Chalk reservoir and where these hardening levels are fractured (fractured hard grounds). The fractured hard grounds give rise to significantly increased production by fracture flow but also cause problems for drilling and production/injection because they set up large pressure differentials and short circuit injected water. 

Most lithification of chalk is caused by early diagenetic cementation at the chalk sea floor, forming hardgrounds. These can be identified using various criteria, most notably mineralization (iron minerals, primarily pyrites, glauconite, phosphate) which coats the surfaces of hardgrounds and burrows penetrating into these, and oxygen and carbon isotopes, which yield values indicative of the derivation of the cement from Cretaceous seawater.

However, there is a seamless transition between soft chalks, through nodular chalks, to highly cemented ones. Because they are formed by seafloor currents, the distribution of hardgrounds is often predictable over large regions. Processes which form hardgrounds include channeling and condensation over highs.

The aim of this project is to develop a predictive model for chalk hard grounds in the North Sea. This model will be integrated into the funders full field model. To achieve this aim will require a multi-disciplined approach using carbon isotope analysis, geochemistry, petrography, micro-analysis, and structural analysis with a sound basis in lithostratigraphy and biostratigraphy. A scoping study has already been completed and this will form the literature review for this phase of work.

It is likely that the project will follow a phased approach: reassessment of the existing biostratigraphy for the Valhall and Hod chalk reservoir cores and integrate with existing work on lithology and lithostratigraphy; the characterisation of selected hardgrounds both from petrographic and geochemical perspectives; understanding of the role of the structure in hardground formation and the lateral persistence of hardgrounds.

As a PhD student you will be working in a dedicated project team with academic leadership by Professor Andy Gale. We are therefore looking for a highly motivated earth science student who is keen to work on a multi-disciplined project with an industrial partner. Technical oversight of the project will be the responsibility of Professor Andy Gale and there will be addition support from Aker BP and the project consultant Dr Jenny Huggett as well as from the University's Graduate School.

There will be the requirement to travel to Norway to inspect and log chalk core early on in the project and to attend a field trip to Texas with Prof Andy Gale and Aker BP to inspect analogue outcrops currently scheduled for October 2019. The project team are also keen that the PhD student will spend up to three months with the client on placement in Norway to gain key industrial experience.

How to apply

We’d encourage you to contact Dr Nick Koor (nick.koor@port.ac.uk) to discuss your interest before you apply, quoting the project code SEES4910319.

When you're ready to apply, you can use our online application form and select ‘Geography, Earth and Environmental Sciences’ as the subject area. Make sure you submit a personal statement, proof of your degrees and grades, details of two referees, proof of your English language proficiency and an up-to-date CV.  

Our ‘How to Apply’ page offers further guidance on the PhD application process.

Please note, to be considered for this funded PhD opportunity you must quote project code SEES4910319 when applying.