Deep Geothermal is possible with the right skillsets and risk management

Deep Geothermal technology allows us to extract the heat of the earth from more than 500m beneath our feet. It offers a potential route for the decarbonisation of traditional heat sources such as gas;  which is a source of about 40% of the carbon emissions in the UK.

Aside from the people of Roman Britain enjoying the natural thermal springs of Bath (which still flow today), only one purpose built exploration well has been drilled in Southampton in the 1980s and a couple of more recent pilot projects in Cornwall, yet other countries around the world have been successfully harnessing the heat of the earth for many decades.

Our historically heavy reliance on gas in the UK has meant geothermal heat has largely been ignored. However, with a focus on the need for a rapid decarbonisation of heat as we drive to net zero, a flurry of projects at varying stages of maturity from early stage concept,, or even on the cusp of construction, are emerging; and it finally looks as though we are set to join the likes of Germany, France and The Netherlands in exploiting this exciting renewable technology.

So how does it work? Geothermal resources can be thought of as a hybrid between natural resources and renewable technology. They are reservoirs of hot water at varying depths and temperatures below the earth’s surface. Wells, ranging from a few 100m to several kms deep, can be drilled to tap the very hot water and steam which can  then be brought to the surface for use in heating and even to provide cooling.

The reward for geothermal energy development is high: it’s renewable, has one of the smallest land-use footprints, requires no expensive facilities retrofit, runs 24/7 whatever the weather; is dispatchable, and offers a  wide temperature-applicability and storage potential.

However, as with any development, these projects have an element of risk. At the outset, drilling deep wells is capitally intensive and logistically complex. .  Whilst we know there is heat, it is critical to optimally place the production well to deliver commercial flow rates which you cannot validate until you have drilled it, emphasising the importance of risk management throughout the project development lifecycle.

These are the risks that engineers through many years of hydrocarbon drilling experience have faced in order to explore for and develop a resource. As more and more wells are drilled and more seismic data acquired, geological risk is also further reduced. That is not to the say the first projects will be inherently more risky, just that a greater degree of reliance on experience and knowledge is needed to deliver successfully. Once successful projects have been implemented and a supply chain established,  the market will have been ‘de-risked’ to an extent, paving  the way for further projects and accelerated investment.

Managing risks in large-scale, complex, drilling projects has been undertaken by the oil and gas industry for decades and a tried and tested approach to standardly identify, categorise and mitigate risks throughout the project’s evolution is well established. We are now applying this deep expertise to the nascent geothermal industry in the UK.

Rik Evans’ presentation from the 2022 IHEEM Conference in Manchester.

About the author
Rik Evans is the Commercial Director for GT Energy. Working initially in the oil and gas service sector and more recently as Head of Integrated Planning and Risk Management for a multi-national Operator he has brought the skills and experiences honed from delivering and working on energy projects around the world to bear on the UK geothermal sector. GT Energy have a number of active geothermal developments across the country including one in Stoke-on-Trent which will be the UK’s first geothermally powered District Heating Network and a pipeline of dozens more in gestation.  www.gtenergy.net