30/11-7

General

Well 30/11-7 was drilled on the eastern flank of the Central Viking Graben, NE of the Frigg Field in the North Sea. The main objectives were to prove gas condensate in the Fulla structure, establish the gas/water contact in the reservoir, and verify Brent Group reservoir quality. Further objectives were to verify reservoir pressure conditions and vertical communication in reservoir. The TD of the well was planned 50 m into the Drake Formation, or to 4068 m TVD RKB.

Operations and results

Wildcat well 30/11-7 was spudded with the semi-submersible installation West Alpha on 12 November 2008 and drilled to TD at 4067 m in the Early Jurassic Drake Formation. No shallow gas was observed by the ROV or on the MWD while drilling the 36" or the 26" holes. Boulders gave slow penetration and heavy vibration between 250 to 300 m. In the 17 1/2" section from 1334 to 3014 m hard rocks, carbonate stringers and cemented sandstone stringers caused slow penetration and numerous bit changes. Intermediate wire line logging was performed at 2910 m while a leak in the top drive DDM was repaired. In the wire line logging at final TD the MDT tool got stuck and was left in the hole. The well was drilled with seawater and spud mud down to 1331 m and with Versatec oil based mud from 1331 m to TD.

The 30/11-7 well penetrated rocks of Quaternary, Tertiary, Cretaceous and Jurassic age. A 12 m thick Draupne Formation shale was encountered at 3722 m overlying a 219 m thick Heather Formation. The main prognosed reservoir sandstones of the Tarbert Formation were not encountered in the well. Top Brent Group, Ness Formation, was encountered at 3953 m. The well proved a lean gas-condensate in sandstone