Drilling of a geothermal well at Akureyri, Iceland, in November 2001. The first 200 meter of the well was drilled with a conventional air hammer but then water in the well prevented further use of this technology. Since the rate of penetration with traditional tri-cone bits was too slow (1 meter/hour) it was decided to use Wassara W100 system. The drilling was carried out by Alvarr/Geovarme, a joint venture between Alvarr ehf and Geovarme AS, with financial support from Orkusjodur (Icelandic Energy Fund).
Result:
The rate of penetration was increased to 25 meter/hour with the Wassara system. Total drilled depth was 404 meter.
Equipment:
Hammer
Wassara W100
Bit
Wassara 115 mm
Pump
Pratissoli MH 45
Drilling fluid
Clean water, no recirculation
Drill pipe
60 mm coiled tubing (2500 meter on the reel)
Formation
Volcanic basalt