24 November 2022
The IEA estimates that globally we must add 3.6GW of geothermal energy generation capacity per year between 2021 through to 2030 to stay on track for Net Zero by 2050.
2020 only saw about 200 MW of geothermal capacity added worldwide – a 2% fall on the previous five-year average, which begs the question, how can the industry innovate to put the heat back into geothermal energy?
Is geothermal energy’s Goldilocks zone ‘just right’?
Traditional geothermal technology relies on abundant and accessible hydrothermal resources such as can be found in Iceland or California. There aren’t many of these goldilocks ‘just right’ locations in the world, and that has stunted growth of the sector.
Of course, if you go deep enough, you can tap into all the heat you’ll ever need from anywhere on the Earth’s surface, precisely the goal of newer enhanced and advanced geothermal systems (EGS and AGS). However, this entails significant new engineering challenges, no small number of which fall under the category of drilling.
How hot is hot?
To understand the challenges of geothermal projects for drilling, we need to understand the temperatures at play. Traditional flash plants, such as those found in Iceland, typically require water temperatures of around 200°C, while newer binary plants can successfully generate electricity with water temperatures as low as 100°C.
These temperatures, although significant, are not unfamiliar to a drilling engineer; a high temperature well in the oil and gas sector is typically understood to have a downhole temperature of around 150°C. At that temperature, the US Department of Energy’s 2019 GeoVision study estimated there is 5,157 GW of geothermal electricity generation potential. Around five times the country’s installed capacity.
There is abundant geothermal energy to be had using temperatures well within drilling engineering’s regular ballpark – but the problem is the nature of the drilling required.
A new direction of travel?
With a couple of centuries of practice under its belt, the oil and gas sector has been responsible for transformative advancements in drilling technology. When it comes to simple, vertical wells, high pressure-high temperature (HPHT) environments are no longer a challenge.
Directional drilling, however, is another matter. In wells where horizontal or extended reach drilling (ERD) is required, smarter engineering is a necessity. If the drilling system can’t handle high temperatures, it can lead to a myriad of operational and financial challenges.
To-date, the pinnacle of directional drilling technology has been the rotary steerable system (RSS), variations of which have been in use for decades, but have historically struggled to perform reliably in HPHT environments.
Handling the heat
Our Steer-At-Bit Enteq Rotary (SABER) Tool represents a radical evolution in RSS design, capable of reliable HPHT performance and greater uptime thanks to a mechanically simple design and at-the-bit steering.
We believe that the SABER Tool can play a key role for the geothermal sector for three main reasons:
- The greater uptime and reliability improve project economics – critical in geothermal where capex is higher, and rewards are less immediately lucrative.
- Drilling deeper brings harder rock. The inherent design of the SABER Tool decouples the internal platform and electronics from strong torsional vibration effects induced by the bit for improved reliability.
- The SABER Tool has been designed from the start to be reliable in the HPHT environments typical of geothermal applications, with a specified max temperature of 175°C.
President Joe Biden has recently signed into law the Inflation Reduction Act which, despite the name, could prove an incredibly significant piece of energy legislation, with as much as $350 billion in loans and loan guarantees for energy and automotive companies – with the help of engineering developments such as the SABER Tool, a slice of that could transform the geothermal energy landscape and put the sector back on track to fulfil its potential contribution to Net Zero.
Learn how the SABER Tool can support your geothermal project.