• Lost 2 out of 3 rock bit cones from hole-opener in hole
• Halted project progress
• Mobilized quickly a 8,3” Magnum Fishing Magnet® by car to drill site
• Ran in hole with magnet on 3 ½” drill pipe, provided cross over for easy make up
• Supplied fishing personnel to supervise the operation
• Fished out lost bit cones effectively in one run
• Prevented delay of large complex project
• No steel cuttings or swarf left in hole, hole good to go for remaining drillin
The Nordlink project is the laying of a large subsea electrical cable from Norway to Germany, for the export of green hydroelectric power from Norway to Europe. The cable will be 623 km long, with 516 km in the sea. The total cost of the project is estimated to 13-17 billion Nok. A critical section of this new power cable is the landfall at the rocky Norwegian coast close to the city of Flekkefjord.
The utility drilling contractor Entreprenørservice AS had drilled a 375 m long 6 ½” pilot hole, with entry point in the mountain, and exit point 25 m below the sea in a fjord. The hole inclination was 20 to 10 degrees. The pilot hole was thereafter opened up to 12 ¼” using a hole-opener with 3 cones. After a bearing failure, 2 of the cones fell off the hole-opener at 264 m, and the operations came to a stop.
Innovar Solutions was requested for assistance and the supply of strong fishing magnets. A large 8,3” Magnum Fishing Magnet® with 1600 kg lifting capacity was mobilized quickly to Flekkefjord. The magnet was run in hole on 3 ½” drill pipe and came out with both hole-opener cones attached on the first attempt.
This quick fishing operation prevented long delays and reduced the risk for this large project. The traditional approach would be to attempt using non-magnetic fishing tools with uncertain success, and in the worst case to use a mill to grind up the lost cones. This would however create a large amount of steel cuttings that would not disappear in a granite formation hole, and that eventually would cause more trouble for the next drill bit/hole opener.
