The National
Energy Authority of Iceland (Orkustofnun/OS) and four of Iceland's leading
energy companies: Hitaveita Suðurnesja (HS), Landsvirkjun, Orkuveita
Reykjavíkur and Mannvit Engineering established the Iceland Deep Drilling
Project (IDDP) in 2000 to advance geothermal energy development. The consortium
is also known as “Deep Vision.”
According to Wikipedia:
“The aim is to improve the economics of geothermal
energy production. Its strategy is to look at the usefulness of supercritical
hydrothermal fluids as an economic energy source. This necessitates drilling to
depths of greater than 4,000 metres (13,000 ft) in order to tap the
temperatures of more than 400 °C (750 °F). The drilling is at a rifted plate
margin on the mid-oceanic ridge. Producing steam from a well in a reservoir
hotter than 450 °C (840 °F)—at a proposed rate of around 0.67 cubic metres per second
(24 cu ft/s) should be sufficient to generate around 45 MW. If this is correct,
then the project could be a major step towards developing high-temperature
geothermal resources.”
The map below shows the position of Iceland along a mid-ocean ridge rift system. This is followed by a simplified geological map of Iceland showing the locations of Iceland's geothermal systems and the three areas, Krafla, Reykjanes and Hengill, of IDDP-1, IDDP-2, and the future IDDP-3:
The first well, IDDP-1, was
drilled into a magma reservoir in 2009. It was planned to be drilled to 4000
meters (about 13,000ft), but stopped when it hit magma at 2100 meters (about
6900 ft). Temperatures in the well were found to be 900 °C (1,650 °F). The well
was thought to be capable of producing about 36MW of electricity if connected
to the grid, but was eventually abandoned due to mechanical difficulties with
equipment affected by the heat.
The first graphic below shows the original design well schematic for IDDP-1, and the As-Built well schematic. The second graphic shows the original drilling and coring plan vs. the actual drilling and coring done for IDDP-1:
Angela Seligman, who has been
documenting IDDP in a blog series for Clean Air Task Force, gives a summary of
IDDP-1 below, followed by a graphic from another source depicting the well
(note that the graphic shows that a titanium-lined casing was used in the
well):
The second well, IDDP-2, was
a deepened well and was drilled to 4,659 metres (15,285 ft). Drilling began in
2016 and was completed in 2017. They were hoping to reach a temperature of 500
°C (930 °F), but the final temperature ended up being 427 °C (800 °F) with a
fluid pressure of 340 bars (4,900 psi).
“Core samples were taken, showing rocks at the bottom
that appeared to be permeable, and fluids in supercritical conditions were
successfully reached, accomplishing all of the main objectives of the drilling
operation.”
Seligman gives a summary of
IDDP-2 below:
The drilling IDDP-1 was
plagued by lost circulation, which is not uncommon with geothermal wells. In
this case, before reaching the target magma, the drill encountered two active
hydrothermal systems where circulation was lost. The lost circulation issues
were resolved with lost circulation material (LCM) and cement. The first time
the well encountered the first hydrothermal system, LCM was not enough to stem
the losses. Then, a decision was made to sidetrack the well, which refers to
plugging the bottom of the hole with cement and coming up the hole to redrill
into that section away from the original hole. The next time they encountered
the hydrothermal zone, they were able to set a cement plug through it in order
to slow the losses of drilling fluid. It worked, and they were able
to drill the hole deeper.
A 2023 paper in GRC
Transactions by Agustin Garbino of the University of Texas at Austin examined
the details of IDDP-1 and the conclusions of the paper are given below:
“Although the first well drilled as part of the Iceland
Deep Drilling Project was unsuccessful in testing supercritical fluids, it
became the world’s hottest producing geothermal well with a record flowing
temperature of 450°C. It proved the existence of a magma chamber at 2 km in
Krafla, where temperature is estimated to be around 900°C.”
“Huenges (2017) defined enhanced geothermal systems as
“geothermal reservoirs in which technologies enable economic utilization of low
permeability conductive dry rocks or low productivity convective water-bearing
systems by creating fluid connectivity through hydraulic, thermal, or chemical
stimulation”. Because its production is believed to be a result from hydraulic
and thermal cracking of a metamorphic formation heated by a magma chamber, the
IDDP-1 well is considered by this definition to be the first productive
Magma-EGS in the world (Friðleifsson et al., 2015, Friðleifsson et al., 2021).”
“When considering the size of the huge magma chamber
based on seismic measurement, it is believed that Krafla power plant could
probably multiply its energy production by an order of magnitude from the
currently installed capacity of 60 MWe (Friðleifsson et al., 2021). However,
several engineering challenges need to be addressed beforehand related to
casing integrity, managing of loss circulation during drilling and surface
equipment design. Thermal strains acting on the casing and corrosive
environments affecting wellhead and surface facilities appear to be the biggest
challenges to overcome before venturing into a development of this kind.”
A paper published in the
Proceedings World Geothermal Congress in 2021 describes the implications and
importance of the two wells, noting about IDDP-2:
“A major achievement of the IDDP-2 well was to
demonstrate that it is possible to drill into a supercritical geothermal
reservoir, while there are shallower feed points that produce subcritical
fluids. Whether the mixture of the saline fluid from different depths will be
capable of generating electric power remains to be seen. Nevertheless, the
major success of the IDDP-2 well is the finding of primary and/or enhanced deep
permeability in very hot rocks. The implication of this finding needs to be
evaluated in the wider context of worldwide supercritical geothermal systems.”
Since drilling induced
hydraulic fracturing in the wells, they are considered to be enhanced
geothermal wells that created an enhanced geothermal system (EGS) when water is
added to the newly made reservoir. The conclusions of the paper are given
below.
“The results from research on the IDDP-1 and IDDP-2
wells thus far, for the future utilization of superhot geothermal systems at
supercritical conditions, have already paid off in increased knowledge and
understanding. It is quite clear that deep EGS systems can be created in
superhot rocks up to magmatic temperatures. Permeable rocks are
found to great depths and permeability is likely to be further enhanced by
hydraulic and thermal cracking during drilling. The geothermal resource base
for similar volcanic systems needs to be expanded downwards by at least 1 km.
Magma EGS (MEGS) systems can be created. Supercritical saline systems are
drillable and usable, if not for direct use, then definitely as deep EGS system
in superhot rocks.”
“Within the next 5 years or so the IDDP-3 well is
planned to be drilled to 4-5 km depth within the Hengill geothermal system,
operated by Reykjavik Energy. Estimated cost of drilling and testing can be
considered similar as for IDDP-2, or about 30 m€, and to this we may add some
20 m€ for pilot tests and power plants related to all the IDDP test sites
(Friðleifsson et al., 2019). In summary, total accumulated cost for the IDDP
project may approach 100 m€ before its conclusion. However, developing geothermal
wells that have power outputs ten times that of currently producing
high-temperature wells remains an alluring prospect, made more credible by the
results to date from the IDDP.”
According to Seligman, IDDP-3
is being planned for drilling, with somewhat different goals.
“IDDP-3 is being planned in the Hengill area in
southwest Iceland and is being led by Orkuveita Reykjavíkur (Reykjavík Energy),
where evidence of superhot formations has been observed at about 2 km depth.
The goal for IDDP-3 has been shifted slightly from the initial goal of the IDDP
to focus on reaching superhot conditions. Accordingly, IDDP-3 is targeting
fluid enthalpy greater than 3,000 kilojoules per kilogram (kJ/kg), rather that
strictly achieving supercritical conditions.”
The graphic below shows some
of the challenges of drilling supercritical geothermal or super-hot rock (SHR),
which include extreme temperature and pressure conditions, materials
challenges, and cost feasibility:
According to the IDDP
website, which does not seem to have been updated since 2022, the goal of the
project is as follows:
“The main purpose of the IDDP project is to find out if
it is economically feasible to extract energy and chemicals out of hydrothermal
systems at supercritical conditions.”
References:
Pushing
the limits of geothermal deep drilling: Exploring the potential of
high-temperature hydrothermal systems in Iceland. Iceland Deep Drilling Project.
Home - IDDP
Iceland
Deep Drilling Project. Wikipedia. Iceland Deep Drilling Project -
Wikipedia
Iceland
Deep Drilling Project: a Review of the Main Challenges and Implications of
Drilling the Well IDDP-1. Agustin Garbino, University of Texas at Austin. GRC
Transactions, Vol. 47, 2023. 1034801.pdf
The
IDDP success story – Highlights. Guðmundur Ómar Friðleifsson, Bjarni Pálsson,
Björn Stefánsson, Albert Albertsson, Þór Gíslason, Einar Gunnlaugsson,
Hildigunnur H. Thorsteinsson, Jónas Ketilsson, Sturla Sæther, Carsten Sörlie,
Wilfred A. Elders, and Robert A. Zierenberg. Proceedings World Geothermal
Congress 2020+1 Reykjavik, Iceland, April - October 2021. The IDDP Success Story - Highlights
An
introduction to the next clean energy frontier: Superhot rock geothermal and
successes from the Iceland Deep Drilling Project. Angela Seligman. Clean Air
Task Force. September 17, 2025. An introduction to the next clean
energy frontier: Superhot rock geothermal and successes from
the Iceland Deep Drilling Project – Clean Air Task Force
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