Global Geothermal Insights: Interview with Sam Abraham the Geothermal Global Technical Advisor at Halliburton
This interview was done by Robert Buluma on 5th of November 7:30 Am EST
At Alphaxioms , we are committed to uncovering the deeper truths behind geothermal energy , the drilling, the risks, the innovations, and the frontiers. Today we welcome Sam Abraham, a veteran drilling engineer whose global geothermal experience spans more than 25 years. From oil & gas beginnings to geothermal hotspots around the world, Sam shares his journey, insights, and advice for the next generation.
Career Journey & Background
Sam, could you tell us about your career path and what led you into geothermal drilling?
I have a background in oil and gas — seven years since 1991. I served as a base manager in Jakarta for three years, and also worked a little in geothermal alongside oil & gas. In 2005 I moved to New Zealand, given its vast geothermal resources. From there I moved to the USA as a drilling engineer. For the past 25 years I’ve held global geothermal positions.
Oil & gas and geothermal are more of the same — but the equipment sizes in geothermal are bigger. The BOP and bit sizes are larger.
Having worked on geothermal projects worldwide, what experiences stand out as the most defining in your career?
One that stands out is Hawaii drilling: you’re sitting 15 km away from a volcano which has been active since 1984 while you wait on a possible magma eruption. To navigate that, we had to innovate our drilling bits, cementing methods, and manage massive logistics — because supply lines had to connect back to Los Angeles, miles away.
“You’re sitting 15 km from a volcano, every decision could mean success or affect the project.”
Technical Expertise & Insights
Geothermal drilling often faces unique challenges compared to oil & gas. What are the key technical differences?
There are very high temperatures, possible volcanoes, and even lava intrusion. Some formations are fragile. Hydrogen sulphide influx. Brine is corrosive. The pH can be 2–3, which affects casing and cementing. Oil & gas may be replenished; geothermal tends to have a PPA of at least 25 years — well integrity is a key factor.
What are the most common drilling challenges you encounter, and how do you solve them?
For temperatures, we use mud cooling – chillers, for example in Hawaii where we hit 300 °C.
For lost circulation:
- Add 5–10% materials like wheat, rice, and peanut husks.
- If severe, 20–25% more additive.
- In extreme cases, 40-45% cement plugs are added.
- ‘Blind drilling’ – drilling without fluid returns – is the most dangerous type of drilling.
Could you share examples of drilling technologies or techniques that have improved efficiency and safety?
We’ve shifted from traditional bits to PDC bits so we can drill harder formations. Traditional tools couldn’t handle directional drilling beyond 150°; newer technologies handle higher temperatures (200 °C and above). Cementing earlier couldn’t go beyond 150 °C; now we can go over 300 °C for more than 25 years. For casing we use carbon silicate, nickel, and chromium alloys.
“Every 10 °C of heat is a new layer of difficulty , but innovation always catches up.”
Global Industry Perspective
Which regions hold the most promising potential for geothermal development?
Africa – the Eastern Rift has more geothermal compared to the West Rift. South America follows (El Salvador, Ecuador) in the Ring of Fire. Indonesia and the Philippines (tectonic boundaries). Australia and New Zealand (Ring of Fire). Japan (tectonic plates). The USA (Alaska, Oregon), Turkey, and Eastern Europe also show potential.
How do differences in geology, policy, and regulation impact drilling success?
Many countries’ mining acts only focus on open/underground mines, while geothermal is deep. In Africa, deep minerals belong to the government. In the USA every state has its own mineral laws. In New Zealand it’s more standardized, and that model should be applied in Africa. Local communities must always be considered, especially when donors enforce frameworks.
“Regulations must catch up with depth, geothermal isn’t surface mining, it’s from the core of the Earth ”
What lessons can emerging geothermal markets learn from Iceland, the USA, or Kenya?
They should ensure regulations are properly structured. Reports must be made for future drilling and recommendations. Improve efficiency and keep safety paramount — in drilling, even on day one, lives can be lost.
Innovation & Future Outlook
With the rise of automation and digital technologies, what role do you see them playing in geothermal drilling?
In the past there was no monitoring. Today we have drilling sensors – weight on bit, pressure volumes, gas sensors. Data is gathered and shown in graphs; alarms sense pressure differences; H₂S calibration with AI is routinely tested weekly and automated.
How important is reducing drilling costs for global geothermal expansion?
In Africa it takes about USD 6 million to drill to 3,000 m. About 40% goes into drilling, 40% into well cost; typically you drill 3-4 wells with one used as injection. If you reduce one day of drilling time, you could save USD 1.5 million — that can fund another well and improve project efficiency.
What advice would you offer to young engineers aspiring to build careers in geothermal drilling?
Many come from mechanical, chemical or petroleum backgrounds. Keep your eyes and ears open. Learn from field engineers. Ask hard questions. Keep all notes — similar problems will crop up 20 years later. Geothermal is made up of 20 departments and they must all work together. Cross-train and build yourself.
“Keep your field notes , this events tend to repeat themselves ”
Closing
Sam’s global career and insights underscore that geothermal drilling is as much about human ingenuity, careful engineering, and constant vigilance as it is about raw heat and geology. At Alphaxioms, we believe these perspectives help push the frontier — equipping companies, consultants, and engineers to unlock the next wave of geothermal growth.
Related: Driving the UK Toward Net Zero: Chris Sladen on Geothermal’s Untapped Potential
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