The IDDP (http://www.iddp.is/) is a long-term program to improve the efficiency
and economics of geothermal energy by harnessing Deep Unconventional
Geothermal Resources (DUGR). The aim is to produce electricity from natural
supercritical hydrous fluids from drillable depths. This requires drilling wells in
active high-temperature (high-T) geothermal systems to depths of at least 3.5
to 5 km, to reach temperatures of 450-600°C, and pressures of 230-350 bar.
Modeling indicates that one such well, at sufficient permeability, e.g. capable of
producing ~2400 m3/h of steam, at temperatures above 450°C, could generate
some 40-50 MW electric. This exceeds by an order of magnitude the power
typically obtained from conventional geothermal wells, e.g. producing the same
amount of steam at 240°C. The long-term plan is to drill a series of such deep
boreholes in Iceland at the Krafla, the Hengill, and the Reykjanes high-T
geothermal systems. Beneath these three developed drill fields temperatures
should exceed 550°C, and the occurrence of frequent seismic activity below 5
km, indicates that the rocks are brittle and therefore likely to be permeable.
The poster shows the IDDP drillhole design, drilling schedule and time plan.
Drilling a fully cased and cemented well to about 3.5 km is scheduled for 2008.
Deepening that well to ~4.5 km could take place the same year, or the year
after, and will be followed by a major flow test and detailed chemical study of
the deep geothermal fluids. Most likely, a mechanical and chemical engineering
pilot test will be needed before power production from supercritical resources is
realized. The IDDP feasibility study assumed a heat exchange system would
be needed, but to a large extent this will depend on the chemical composition
of the supercritical fluid, which most likely will be retrieved at the surface as
The main financial supporters are leading Icelandic energy companies together
with the government of Iceland. Negotiations are already underway with
international aluminum companies for participation in the innovative IDDP
experiment. The International Continental Drilling Program (ICDP) and the US
National Science Foundation (NSF), have already allocated funds for scientific
studies by supporting considerable core drilling in the deeper parts of the IDDP
well. The plan is to seek additional funds to the EC-FP7 for developing the
engineering pilot plant test of the supercritical fluid for power production, likely
to be needed in 2009-2010. The EC-FP6 support HITI project is intimately
linked to the IDDP project.