Deep geothermal means wells drilled kilometres into rock known mostly from seismic surveys, producing hot, pressurised water that must be brought up and put back for decades. The wells are typically the biggest cost in the project, rig time is paid by the day, and approval sits with a regulator rather than a planning desk. That is the part of geothermal we work on.
What we do in deep geothermal
- Subsurface evaluation: how hot the rock is, how easily water moves through it and where the faults are, with what has been measured kept apart from what has been assumed.
- Drilling and well engineering: from Basis of Design through detailed engineering to rig-site supervision, to standards such as NORSOK, ISO and API, with the design basis changed for heat, temperature swings and corrosive brine.
- Regulatory support: groundwater, seismicity people can feel and the monitoring plan behind them, prepared before the well design is frozen.
- Technical due diligence: for buyers and funders of geothermal assets, where the key number may be the flow the wells can sustain.
Why oilfield experience matters here
The people who have designed and supervised wells kilometres deep mostly learned the trade in oil and gas. The rigs, casing, cement, pressure control and contractors are largely the same, and so are the ways a well goes wrong. What a developer pays for is judgement in three places: at the design review, at the contract and at the rig.
Oil and gas experience is not the whole answer. A hot-water well lives with heat and corrosive brine for its whole working life, so we keep the oilfield discipline and change the design basis. Ask any consultant where they would depart from a hydrocarbon standard, and why.
Work we can point to
- For Geothermie-Schweiz, the Swiss geothermal association, our partner Vincent Geyl carried out the deep geothermal drilling regulation project of the TRANSFER programme in 2023 and 2024. See the programme.
- In Switzerland we provide independent geological assurance on a deep geothermal project, in support of the cantonal authorities.
- Our anonymised engagement “Deep geothermal wells, delivered to standard”: oilfield well-delivery discipline for a developer drilling where the rules were written for hydrocarbons.
Guides for geothermal developers
Common questions
What separates a deep geothermal consultant from a shallow one?
Shallow geothermal means boreholes a few hundred metres deep, a loop of pipe and a heat pump. Deep geothermal means wells kilometres deep, rig time paid by the day and approval by a regulator. Few skills carry over, so the first question for any team is whether its people have designed, drilled or reviewed wells at your depth and temperature.
Can oil and gas well standards be used for geothermal wells?
As a starting point, yes: the rigs, casing, cement and pressure control are largely the same. But a geothermal well lives with heat, temperature swings and corrosive brine for decades, so the design basis has to change. A good consultant can say where they would depart from the hydrocarbon standard, and why.
When should a geothermal developer start talking to the regulator?
Before the well design is frozen. The questions that dominate are groundwater and seismicity people can feel, so a credible plan for monitoring, and for slowing down or stopping, matters as much as the resource estimate.
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