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 
superheated steam.

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.

Campus SIAF, SP del Monte Volterrano
Localita' Il Cipresso
Volterra, Italy