A fully coupled XFEM model for hydraulic fracturing in multi-phase porous media, Engineering – PhD (Funded) Ref: 3405

About the award

Supervisors

Professor Akbar Javadi, University of Exeter
Professor John Coggan, University of Exeter

Location:

Engineering, Streatham Campus

The University of Exeter’s College of Engineering, Mathematics and Physical Sciences is inviting applications for a fully-funded PhD studentship to commence in February 2019 or as soon as possible thereafter.  This studentship is supported by the College and a National Productivity Investment Fund studentship awarded by NERC Centre for Doctoral Training in Oil and Gas. For eligible students the studentship will cover UK/EU tuition fees plus an annual tax-free stipend of at least £14,777 for 4 years full-time, or pro rata for part-time study, and an annual Research Training Support Grant of £5,000pa. The student would be based in Engineering in the College of Engineering, Mathematics and Physical Sciences at the Streatham Campus in Exeter.

Project Description:
Gas produced from shale has revolutionised the oil and gas industry in the US and is a potential resource in many countries including the UK. Production is dependent on hydraulic fracture stimulation. In shales, which are extremely low permeability, fracture stimulation depends on the presence of a natural fracture network (open or filled) having a large surface area available for connection to the well. Shale gas has the potential to revolutionise the energy supply and have a significant impact on the economic development and energy security and diversity in the UK and throughout the world. This is contingent on increasing the efficiency by improving the current understanding of the processes involved. Shale gas development has met with considerable resistance for environmental reasons. The main concerns relating to the stimulation process are: (i) The intensity of surface disturbance by fracturing operations (site preparation etc); (ii) Fracturing water usage, storage and disposal of large volumes of flow back fluid; (iii) The potential for induced seismicity; and (iv) The potential for leakage of fracturing fluids to surface aquifers.
Although hydraulic fracturing has been used for several years, a thorough understanding of fracking processes is still lacking. To increase efficiency and meet political, environmental and public concerns it is essential to improve the current understanding of the geomechanical processes which occur during fracture stimulation which is the focus of this proposal. In this study, we will build on our extensive experience in modelling of fracture propagation in porous media to develop a fully coupled hydro-mechanical model for hydro-fracturing of porous media with existing discontinues. Two fluids will be considered: one representing the fracturing fluid and the other the host fluid. Flow through fracture will be defined based on lubrication assumption, while flow through the matrix will be expressed as Darcy flow. The fracture discontinuity in the mechanical model will be captured using eXtended Finite Element Method (XFEM) while the fracture propagation criterion will be defined through cohesive fracture model. The developed model will provide a valuable tool that can be used for (i) evaluating the hydraulic fracturing process and fracture propagation, (ii) predicting induced seismicity, and (iii) assessing potential leakage from the system and fate of contaminants in subsurface environment. Using this novel approach further understanding of the processes involved and their impacts can be achieved.

The studentship will cover a stipend at the minimum Research Council rate, currently £14,777 per annum, research costs of up to £5,000pa and tuition fees at the UK/EU rate for students who meet the residency requirements outlined by NERC.  Students from EU countries who do not meet the residency requirements may still be eligible for a fees-only award but no stipend.  Applicants who are classed as International for tuition fee purposes are not eligible for funding.  Further information about eligibility can be found here.
You will join the NERC Centre for Doctoral Training in Oil and Gas and you will be required to attend a 20 week residential training programme. Full attendance on this course is a requirement of the funding. Further details can be found at http://www.nerc-cdt-oil-and-gas.ac.uk/training-academy.html

Entry requirements

Applicants for this studentship must have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of science or technology. 
If English is not your first language you will need to have achieved at least 6.0 in IELTS and no less than 6.0 in any section by the start of the project.  Alternative tests may be acceptable (see http://www.exeter.ac.uk/postgraduate/apply/english/).

How to apply

In the application process you will be asked to upload several documents. 
• CV
• Letter of application (outlining your academic interests, prior research experience and reasons for wishing to undertake the project).
• Transcript(s) giving full details of subjects studied and grades/marks obtained (this should be an interim transcript if you are still studying)
• Two references from referees familiar with your academic work. If your referees prefer, they can email the reference direct to stemm-pgr-admissions@exeter.ac.uk quoting the studentship reference number.
• If you are not a national of a majority English-speaking country you will need to submit evidence of your proficiency in English
The closing date for applications is midnight on 07 January 2019.  Interviews will be held on the University of Exeter Streatham Campus the week commencing 14 January 2019.
If you have any general enquiries about the application process please email stemm-pgr-admissions@exeter.ac.uk or phone +44 (0)1392 722730 or +44 (0)1392 725150.  Project-specific queries should be directed to the main supervisor.

Summary

Application deadline:7th January 2019
Number of awards:1
Value:£14,777
Duration of award:per year
Contact: Postgraduate Research Office stemm-pgr-admissions@exeter.ac.uk