Promising new well at Nesjavellir geothermal plant, Iceland

Promising new well at Nesjavellir geothermal plant, Iceland Nesjavellir geothermal plant, Iceland (source: ThinkGeoEnergy, creative commons)
Alexander Richter 26 May 2021

A new well drilled at the Nesjavellir geothermal plant near Reykjavik, Iceland shows promising results and rather high temperature of 360 degrees Celsius.

Icelandic geothermal power operator ON Power reports promising initial test from a new well drilled at the 120 MW Nesjavellir geothermal power plant.

There was considerable anticipation among those present when a new production well drilled at the Nesjavellir power plant was tested in the beginning of this week on location near Reykjavik, Iceland. The reason is that the bottom of the well, which is almost 2,400 meters deep, is one of the hottest that has been drilled in this country. The new well, called NJ-32, is promising, but testing will last for several weeks.

The well was drilled east of the Nesjavellir area last summer by Iceland Drilling. It is directionally drilled and its bottom is below the valley to the west. There is also a bottom borehole called NJ-11. This well is historic because in it the bottom temperature was measured at 380 degrees Celsius, but the meter used at that time could not measure higher. This was in 1984 and people did not see to it that the equipment they had to control the steam from the well withstood the heat and the pressure in it. It was therefore cast for the lowest and hottest currents in the well, but it has nevertheless been one of the most reliable production wells in the power plant.

Drilling rig at Nesjavellir, Iceland June 2020 (source: ThinkGeoEnergy, creative commons)

The maximum temperature at the bottom of the new well was 360 degrees Celsius. It was shortly after its drilling was completed. There is some uncertainty about the properties of the geothermal fluid that comes from such hot wells. It can be more economical than is generally the case and there is a greater risk of equipment used in energy production corroding.

The first measurements on the new well are promising, the acidity level is normal and the proportion of steam from what comes out of it is higher and this is a good sign.

Source: Company release