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PhD Opportunity: Geological controls/ deep geothermal, University of Exeter

Pernzance, Cornwall, UK (source: flickr/ The Brit_2, creative commons)
Alexander Richter Alexander Richter 19 Jan 2018

The Camborne School of Mines at the University of Exeter has published a PhD opportunity on "Geological controls on upper crustal heat flow for deep geothermal energy in Cornwall, Camborne School of Mines".

The University of Exeter has published an opportunity for a PhD position on “Geological controls on upper crustal heat flow for deep geothermal energy in Cornwall, Camborne School of Mines” – MPhil/PhD Ref: 3011

About the award

The University of Exeter’s College of Engineering, Mathematics and Physical Sciences, in partnership with GeoScience Ltd, is inviting applications for a NERC Industrial CASE PhD studentship to commence in September 2018 or as soon as possible thereafter.  For eligible students the studentship will cover UK/EU tuition fees plus an annual tax-free stipend of at least £14,553 for 4 years full-time, or pro rata for part-time study.  The student would be based in the Camborne School of Mines in the College of Engineering, Mathematics and Physical Sciences at Penryn Campus in Cornwall.

Location: Camborne School of Mines, Penryn, Cornwall,

Academic Supervisors

  • Dr Robin Shail, University of Exeter
  • Dr Tony Batchelor (CASE Industrial Supervisor, GeoScience Limited)
  • Professor Frances Wall, University of Exeter
  • Professor Mark Smethurst, visiting professor, University of Exeter
  • Dr James Hickey, University of Exeter

Project Description

SW England has locally high surface heat flows associated with elevated levels of radioactive elements U, Th and K within the Early Permian granites of the Cornubian Batholith. As such, it is one of the most prospective areas in the UK for deep geothermal energy. Previous investigations into the regional deep geothermal energy potential included the Hot Dry Rock (HDR) geothermal research programme, undertaken by Camborne School of Mines (1975-1991).

There is now renewed interest in this technology. The United Downs Deep Geothermal Power project will commence drilling two wells into the Carnmenellis Granite in 2018, one 2.5 km deep and the other 4.5 km deep; this will result in the UK’s deepest onshore geothermal borehole and provides the project context.

The purpose is to address uncertainties regarding heat production and conduction models in the Cornish crust which include: (i) radioactive elements U, Th and K are not present in sufficiently high quantities within the previously investigated upper parts of the granite to account for observed heat flow, (ii) He-4 production from historical deep geothermal wells is higher than anticipated, and (iii) geophysical modelling has progressively reduced the interpreted thickness/volume of the Cornubian granites. These inconsistences imply substantive heat source(s) may occur within, or below, the deeper parts of the batholith.

The project will develop further understanding of the controls on upper crustal temperatures and deep geothermal energy exploitation in Cornwall and how this might relate to: (i) heterogeneous radiogenic heat production within the composite Cornubian Batholith (presently unsampled below 2.6 km), (ii) heat contributions from mid/lower crustal and mantle sources, and (iii) modification by fracture-controlled deep groundwater circulation. Drilling within the Carnmenellis Granite will occur over a depth range of approximately 0.8-4.5 km.

The arisings and limited sidewall core samples will permit mineralogical and whole rock geochemical characterisation of granite variation, including the U, Th, K budget and their mineralogical hosts and evidence for high-temperature alteration and leaching. Analytical techniques include optical microscopy, QEMSCAN (automated SEM), electron microprobe and XRF/ICP-MS.

The use of QEMSCAN is novel as it permits rapid mineralogical analysis and host rock interpretation from fine-grained drilling arisings. These data will be complemented by those obtained during downhole logging (gamma ray, formation fluid composition / temperature). Radiogenic heat production will be modelled and compared with measured heat flow data. Discrepancies will be evaluated in terms of the potential role of upper crustal convective fluid flow and/or mid / lower crustal and mantle heat contributions using existing deep geophysical data and an understanding of admissible scenarios during the post-Variscan tectonic evolution of SW England. Confirmation of deeper heat sources would have profound implications for regional geothermal and crustal models and deep geothermal projects in granitic terrains globally.

The student will receive training at Camborne School of Mines in: (i) mineralogical and geochemical analytical and interpretation skills, (ii) petrological and heat flow modelling skills, and (iii) regional crustal evolution. Training in downhole log interpretation and fracture-controlled fluid flow models will be provided by GeoScience Limited.

The studentship will be awarded on the basis of merit for 4 years of full-time study to commence in September 2018 and is subject to confirmation of funding.

The studentship will cover a stipend at the minimum Research Council rate, currently £14,553 per annum, research costs and tuition fees at the UK/EU rate for students who meet the residency requirements outlined by the 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.

More project opportunities within Camborne School of Mines can be found here.

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 Geology or related discipline.

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/).

For further details see link below.

Application deadline: 5 February 2018

Source: University of Exeter