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If successful Icelandic project could derive 30 to 50 MW from one geothermal well

Drilling Rig Thor of Iceland Drilling (source: Iceland Drilling)
Alexander Richter 19 Jan 2017

The Iceland Deep Drilling Project continues successful path on its research on utilising supercritical heat from deeper geothermal wells expanding power output from around 5 MW today to 30-50 MW per well.

Reported already in December, the Icelandic Deep Drilling Project (IDDP) has reached an extremely important milestone. Announced before Christmas, the project partners report having reached a depth of 4.626 metres and thereby being the deepest well ever drilled in Iceland so far.

But despite the success so far, one has to be cautious, as Ásgeir Margeirsson, CEO of project partner HS Orka said. “There is no guarantee that things continue to go smoothly, as at such depths much can still go wrong quickly.”

“We cannot talk about success just yet. But results so far certainly increase expectations. All this can take a sudden end, because for some reason you can not drill deeper. In previous experiments that’s exactly what happened, “says Asgeir and refers to the deep borehole that was drilled geothermal area at the Krafla geothermal area in the North of Iceland in 2008 and 2009. It was the first hole in the deep drilling project (IDDP-1).

When asked further about the stage which has now been reached, Mr. Margeirsson says that the first stage was to get down to 3,000 meters and tackle feeding hole, the next step was to get down to 3,500 meters and start the actual deep drilling. Reaching a depth of 4,000 meters was the next milestone and to get even down to 4,500 meters shows the success of the project so far. This is particularly important, as it also helped us to receive drill core rock samples that provide valuable information. Being able to gather samples from a depth of 4,300 meters is a new achievement in Iceland’s geothermal history.

“This is probably the deepest well having been drilled under such circumstances, and therefore one can talk about many milestones having been reached. This is thanks to the good preparation work which was extremely elaborate.”

Due to the nature of the project, preparation had to be approached under a complete different mindset compared to conventional drilling and these were great efforts to secure the best personnel, equipment, materials and technologies for the project. This is all based on the extensive experience gained from the drilling of the first well of the project at Krafla in 2008/ 2009. The estimated cost for the project so far is approximately ISK 2 billion (around $18 million). In comparison, conventional production wells in geothermal areas in Iceland is in the range of ISK 500-700 million ($4.4-6.8 million). With that one can add the initial costs of the drilling of the well to 2,500 meters, as the current drilling utilised an existing well and has been drilled deeper from that level.

The Iceland Deep Drilling Project is led by Icelandic energy company HS Orka in cooperation with Norwegian oil firm Statoil and other companies. IT was established in the year 2000, with the founding project members HS Orka, Landsvirkjun, Reykjavik Energy and the National Energy Authority of Iceland.

Iceland Drilling is the drilling contractor for the project utilising its powerful drilling rig Thor. The rig is using electricity, derived from the nearby geothermal power plants of HS Orka in the area. The project group further includes engineering consultants from ÍSOR (ÍSOR) and universities and the scientific community – and was able to secure foreign grants for the project, for example, EU research grants. Therefore the costs for the project are being covered by many participants – both in Iceland and internationally.

The purpose of deep drilling project is to evaluate whether it is possible to generate electricity from deep geothermal systems that could increase the energy output of high heat geothermal areas extensively and thereby minimize environmental impact and land use for energy production, as well as decrease the cost of energy production.

“So far, we have learned a lot. And no matter what happens with the well, there is a lot of experience already gained, even if we cannot use it. The well could for example be used for reinjection, basically injecting fluids into the system which we utilise for our operations. The best result though is that we gain a powerful production well.

A powerful production well for the project could lead to further geothermal development in the geothermal world, in Iceland and elsewhere. It would prove that it is possible to drill deeper and more powerful wells, that will enable to gain the same energy output from fewer wells. With that we would see less impact of development on the environment and see less land use – which is very important in today’s world. IT would further reduce the cost of energy production”, so Margeirsson.

The technology to be used for production will have to be determined after evaluating the geothermal fluid found at those depths. If the composition of the fluid is manageable and one can work directly with superheated steam, as expected, this would be the preferred result as it would help increase energy production on the Reykjanes Peninsula. The project plans to drill down to 5,000 meters and the expected temperature is between 400 and 500 degrees Celsius.

There are indications that the temperatures are extremely high, but one cannot be sure for now, as the well have to be cooled during the drilling activities. “So while it has not been determined, there is evidence of temperatures of over 400 degrees Celsius”, so Margeirsson.

“It is not of absolute importance to reach the target of 5,000 meters is reached or not, the outcome will be the same at a depth at 4,500 meters or 5,000 meters, so Margeirsson.” The well will then be prepared for production, followed by various measurements and scientific research. This work will take all up to two years.

“So maybe there will be the establishment of a success one year after the drilling concludes, how the well behaves over time and how realistic the utilisation for energy production is. The target though is to utilise the well as a production well that will be more powerful compared to traditional wells in the geothermal field. normal geothermal wells in Iceland provide around 5 MW, and the project partners believe that it is not unrealistic to expect between 30-50 MW wells from wells similar to the one being drilled right now. But all of this is now being researched and there is no prove of concept just yet.

This article is adapted from an original article in the Icelandic media in December 2016.

Source: Visir.is, IDDP