Drilling of 250-300 meter deep survey holes at LKAB Kiruna iron ore mine in northern Sweden. The purpose of the holes is to determine ground movement during mining of the iron ore body under the lake by Kiruna. The reason for choosing Wassara was the demand for long straight holes.
The customer was LKAB and the drilling contractor Norrfjärdens brunnsborrning.
Result:
Despite very difficult drilling due to fractured formation the project was completed according to plan. Using the drilled holes it was possible to verify the reliability of previously installed seismic sensors.
Equipment:
Hammer
Wassara W100, 109-113 mm steering ribs
Bit
Wassara 111-115 mm
Pump
Wassara pump unit, WASP 1
Drilling fluid
Clean water
Drill pipe
OD 89 mm, wall thickness 6,3 mm, length 2 and 3 meter
Rig
Nemek 300
Formation
Granite, partly fractured