Utilizing well tractor technology has cut Statoil's downhole maintenance costs by several hundred million kroner.

"We saved NKr500 million on such operations in 2003," reports Stephen Stragiotti, discipline leader for mechanical cable and tractor operations in well interventions in Statoil's Technology entity. "In addition, our earnings increased by NKr300 million because production wells were brought onstream faster and the recovery factor could be improved."

This 6-m long device is an electrically-driven wheeled vehicle, which pushes equipment as much as 8 km along the horizontal sections of oil wells. The power cable is used to extract it from the well once an operation has been completed.

Applications include plugging, perforating, and logging in production wells, but are being steadily extended to help maintain output from commercially-marginal producers.

Statoil completed seven tractor-based operations on fields it operates in 1996, but that figure rose to 71 in 2002 and 127 in 2003. Since in 1996, when Statoil first tested them, well tractors have covered 1,700 km through horizontal wells operated by the group.

7/20/04