StatoilHydro drills long horizontal Gulltopp well from Gullfaks-A

April 14, 2008
StatoilHydro drilled and completed the 9,910 m-long horizontal Gulltopp well from the Gullfaks-A platform, in 439 ft of water.

Nina Rach
Drilling Editor

HOUSTON, Apr. 14 -- StatoilHydro drilled and completed the 9,910 m-long horizontal Gulltopp well from the Gullfaks-A platform, in 439 ft of water.

Drilling began in April 2005. Gulltopp began producing this month from the shallow Brent reservoir at 2,430 m subsea. Platform rig contractor Seawell Ltd. drilled most of the wellpath at an inclination of 7º. In order to counteract the friction, Seawell filled the 8-km casing with air, instead of drilling mud, and "floated" the casing in the nearly horizontal well. "This was the key to success," said StatoilHydro.

The company had to upgrade the brake system on the drilling rig and the power supply for the platform in order to complete the well.

StatoilHydro initially estimated the cost of drilling the extended reach well at $43.9 million, about 25% of the cost it estimated necessary to develop Gulltopp using a subsea template and dedicated multiphase flowlines (OGJ, Feb. 9, 2004, Newsletter).

StatoilHydro said in an Apr. 14 press release that the well was "considerably more expensive than initially assumed."

Gulltopp is in the Tampen area of the northern Norwegian North Sea, 5 km north of Gullfaks satellite fields Gullveig and Rimfaks. It's operated by majority owner StatoilHydro 70%, on behalf of license partner Petoro AS 30%.

Contact Nina M. Rach at [email protected].