30/3-10 S

General

Well 30/3-10 S is located in the Northern North Sea at the eastern flank of the Central Viking Graben, SE of the Huldra Field. The 30/3-10 S well was the second well to be drilled on the Canon structure. The Discovery well 30/3-9 was the first. The main objective of the well was to appraise hydrocarbons within the Brent Group of Jurassic age and prove additional hydrocarbons in the Statfjord Formation of Jurassic-Triassic age. Further objectives were to verify reservoir properties, fluid contacts, and fluid properties and to test up flank erosion of the Brent Group. Planned TD was 50 m into the Lunde Formation of the Triassic prognosed at 4298 m TVD RKB.

Operations and results

Appraisal well 30/3-10 S was spudded with the semi-submersible installation West Alpha on 14 February 2009 and drilled to TD at 4168 m in the Early Jurassic Statfjord Formation. No overpressured shallow gas was observed by the ROV at the wellhead or by the MWD while drilling the 36" and the 26" holes. The well was drilled vertical down to 2850 m before deviation was initiated. It was drilled with Spud mud down to 1412 m, with Versatec OBM from 1412 m to 3672 m, and with Versatherm OBM from 3672 m to TD.

The well penetrated rocks of Quaternary, Tertiary, Cretaceous, and Jurassic age. The top Brent Group was encountered at 3737 m, 75 m TVD shallow compared to the prognosis. It was 12 m TVD thick only and consisted of Ness Formation only. The top Statfjord Formation was penetrated approximately 224 m shallower than prognosis. The Brent Group proved as expected gas with a fluid gradient of 0.29 bar/m. No gas/water contact was observed. The Statfjord Formation proved to be water bearing.

High ga