US oilfield services player Baker Hughes sees geothermal projects playing an increasingly key role in energy supplies in the coming decades as power buyers transition away from conventional fossil fuel-derived supplies.
Tom Thissen, the company’s senior vice president of integrated well services, said that, while oil and gas will continue to play a major role in the company’s business for the foreseeable future, “we are also evaluating key growth areas associated with energy transition, including geothermal".
While only 0.1% of the global energy mix currently comes from geothermal, Thissen pointed to an increase in its use and development in places such as the Netherlands, Turkey and Indonesia.
According to last year's US Department of Energy (DoE)’s GeoVision report, geothermal power generation in the US “could increase nearly 26-fold from today — representing 60 gigawatts of installed capacity by 2050".
The DoE is funding research into geothermal technologies and processes, while government incentives — particularly in Europe’s fast-growing geothermal sector — are helping to de-risk projects.
Long history in geothermal
Baker Hughes has been working in the geothermal space for about 40 years, so the growing interest in this energy source is welcomed by Thissen.
“We routinely provide geothermal services that range from geophysical modelling and reservoir analysis to well drilling and construction in more than 20 countries across five continents," he said in response to written questions.
Geothermal projects — some with 30-year time horizons — require significant up-front capital spending to get them going, but once up and running, operating costs are very low.
Thissen admitted the biggest risk associated with individual projects is the high capital investment needed for exploratory wells and their construction.
Well construction costs can be very high due to challenging rock formations, high temperatures and the lengthy drilling process.
As a result, de-risking projects through a better understanding of the sub-surface geology is critical to success.
“Since operators are essentially paying for 30 years of energy upfront, a lot of effort is put into reducing the project cost, increasing the reliability of technology and reducing uncertainty to mitigate as much risk as possible,” said Thissen.
These are all areas, he said, that Baker Hughes is working on to develop improved geothermal solutions alongside a commitment to technology development and emissions reductions.
Advanced in-house tech
Over the last four decades, the US company has designed and constructed geothermal wells for large-scale power generation schemes, but has also been heavily focused on research results “that push the limits of what was thought possible”, remarked Thissen.
As an example, he cited the case of drilling equipment the company deployed in 2017 to drill “the longest, deepest and hottest geothermal well” in Iceland as part of the Deep Drilling Project 2.
Also in Baker Hughes’ technology arsenal is what is claimed to be “one of the largest downhole pumps in the world” that can produce “vast volumes of water at high temperatures", helping operators achieve heat and power production goals.
In addition, the company operates several test facilities around the world where it can simulate real-world geothermal conditions, mimic well fluid compositions and “rapidly produce prototypes with the use of additive manufacturing.”
One such site is located at Celle near Hamburg in Germany where, said Thissen, “we can emulate the conditions of geothermal wells to test everything from high temperature materials and components to full bottom hole assemblies and submersible pumps".
Germany’s government is leveraging geothermal in a massive way to reduce gas demand, particularly for heating and cooling needs, in Munich.
There is a lot of overlap between the experience, skills and technology in Baker Hughes’ conventional oilfield services business and what is needed in the geothermal industry.
“We have technology and subject-matter experts in nearly every active geothermal region who are already familiar with the challenges of operating in high-pressure, high-temperature applications,” said Thissen.
If the contractor’s standard technology is not suitable to a project’s needs, Baker Hughes will look to tools and services it has developed to handle extreme reservoir conditions.
Geothermal is a focus area for Baker Hughes’ R&D and product management teams, with enhanced geothermal systems (EGS) and advanced geothermal systems (AGS) being studied, both of which, Thissen said, could significantly increase geothermal energy production around the world.
EGS involves injecting water into hot rock that has both limited fluid content and restricted permeability.
If injected at an appropriate pressure, this water can boost rock permeability by creating a network of fractures, while the injected water would eventually create a geothermal reservoir.
A production well is then drilled into the fracture network and the resulting circulation loop would allow water to flow through the “enhanced” reservoir, picking up in-situ heat.
Hot water is then pumped to the surface through the production well where the water either flashes to steam or it heats a working fluid that produces vapour.
This steam or vapour is then used to turn a turbine to create electricity and the original geothermal water is recycled into the reservoir.
AGS is similar to EGS but calls for the inter-connection of two horizontal wells in a hot reservoir and running water through it in a loop via two surface facilities.