StatoilHydro has joined an initiative that aims to tap ultra-deep geothermal energy sources in Iceland with a view to generating huge quantities of electricity sustainability. Success could deliver a tenfold increase in the amount of energy harvested from existing wells.
One of the partners is Alcoa, which has, for some years, wanted to build a huge new aluminium smelter (capacity 250,000 tonnes a year) on Iceland, the preferred location being Bakki.
Aluminium smelting is hugely energy-intensive and the Alcoa proposal is linked with Iceland’s Theistareykir and Gjastykki geothermal projects.
Other members of the Iceland Deep Drilling Project (IDDP) consortium comprise the local power companies, Hitaveita Sudurnesja, Landsvirkjun, Orkuveita Reykjavikur, together with Orkustofnun.
IDDP could see up to three wells drilled initially, plus the construction of a pilot power plant by 2015.
The first IDDP well will be drilled at the Krafla geothermal field in the latter part of 2008 and early spring 2009 and tested the same year. Pre-drilling of this first well with a 36in casing has already started.
Two optional wells – target depth will be 4,000m – are scheduled to be drilled at the Hengill (IDDP well 2) and the Reykjanes (IDDP well 3) geothermal fields during 2009-11 and subsequently deepened. Pilot plant testing should be completed about 2015.
Each of the Icelandic power companies has already made a commitment to drill, at its own cost, one 3,500-4,000m well in a geothermal field which it operates. These wells will be designed so that they will be suitable for deepening to 4,500-5,000m.
The main objective of the IDDP is to investigate whether it is economically feasible to produce energy and chemicals from geothermal systems at supercritical conditions.
This will require drilling to depths of 4,000-5,000m in order to reach temperatures of 400-600C.
Today, typical geothermal wells range up to 2,500m depth and produce steam at about 300C and at a rate sufficient to generate about 4-7MW of electricity.
It is estimated that producing steam from a 4,000-5,000m deep well penetrating a reservoir hotter than 450C could generate 40-50MW of electricity.
If testing this idea proves successful, it could lead to a major step forward in the economics of developing high-temperature geothermal resources worldwide.
Investigating such deep high-temperature geothermal resources requires highly developed drilling and well-testing technology and may need modification of techniques for steam treatment and energy production.
This is where StatoilHydro has an important role to play because of its track record of drilling challenging offshore wells in its quest for oil&gas resources.
The Icelandic initiative has apparently generated considerable international science interest since the beginning of the project.
In 2005, both the International Continental Scientific Drilling Program (ICDP) and the US National Science Foundation (NSF) made significant grants to support the IDDP science programme.