On April 8, StatoilHydro set a new world record by drilling and completing a well just short of 10km in length from a North Sea platform.
Gulltopp was drilled from the Gullfaks A to an oil and gas pocket that is now being produced. It is its most complex well yet, says StatoilHydro
Sigve Nylund, head of “operations west” at the company, said: “The experience gained is very valuable to the further development of both remote prospects at Gullfaks and on other fields in StatoilHydro’s portfolio. The increased range we now envisage for platform drilling opens up new perspectives for effective exploitation of existing infrastructure, and increased producing life.”
Gulltopp should, together with other prospects in the area, secure continued Gullfaks operations towards 2030. A key innovation was the decision to replace the drilling muds employed traditionally during wellbore casing installation with air. This served to reduce friction and make the casing lighter during handling operations.
The hope was that this would enable Gulltopp to be drilled the way it was. This is an exceptionally shallow oil deposit. For each metre to be drilled down, it was necessary to drill four metres horizontally.
The alternative to drilling this distance would be to locate a subsea template on the seabed. This, however, would be far more expensive than drilling from an existing platform.
The Gulltopp discovery was proven in 2002 and drilling started in April, 2005. Recoverable resources are 25million barrels of oil and 500million cu m of gas. Licensees are StatoilHydro (70%) and Petoro (30%).