Philip Henes

PhD title: Geological controls on heat production and the evolution of fracture systems.

Primary Supervisor: Dr. Robin Shail

Co-Supervisor: Professor Hylke Glass

My research is based on the data collected from Eden Geothermal Ltd's first geothermal well, EG-1, completed in November 2021 in the southern part of the St Austell Granite. My project is one of two in Geothermal Resource Extraction offered in partnership with Eden Geothermal Ltd., EGS Energy , and Bestec (UK). The other project is being carried out by Ben Adams whose project is on the "Estimation of geothermal resource in place within a deep fault system".

Using data obtained during drilling, this project is generating knowledge and understanding of two aspects of geology which are critical to the successful exploitation of deep geothermal energy across SW England. These two aspects are:

The effect of granite variation on heat production.

• Drill cuttings obtained during drilling will allow for mineralogical, mineral chemistry and whole rock heterogeneity characterisation of the St Austell granite with depth.
• With this the budget of heat-producing elements, their mineralogical hosts, evidence for HT alteration, and any evidence for element leaching can be determined.
• Combining these data with measured downhole wireline data, discrepancies can be further evaluated which could be due to external heat resources ie. lower/mid crust vs mantle heat sources.

The effect of fracture and vein system control on geothermal reservoir permeability.

• Southwest England's vein and fracture system is well constrained at surface but basically unknown below 2.5 km.
• Downhole wireline techniques can be used to orientate structures encountered during drilling and drill cuttings can be used to characterise these structures in terms of their mineralisation, if any.
• The aim is to establish the orientation and nature of fractures and infills that have been most susceptible to reactivation during the post-Variscan tectonic evolution of SW England, as this is likely to be an important control on the development of fracture permeability at reservoir depths.

ACADEMIC QUALIFICATIONS

• BSc (Hons) Geoscience, 2015 (Keele University)
• MSc Earth Structure & Dynamics, 2018 (Utrecht University)