34/10-46 B

General

Well 34/10-46 B was drilled to a structure 5 km southwest of the Gullfaks field. Running the liner in well 34/10-46 A failed due to restrictions in the hole and well 34/10-46 B had to be drilled. The primary objectives of the well were to be a water injector in Tarbert Formation in segment D1 and to be a drain point in the top reservoir for oil and gas from Krans Member (Kyrre Formation)/Brent Group in segment D1. The secondary objective was to explore a Cretaceous prospect west of wildcat well 34/10-12.

Operations

The appraisal well 34/10-46 B was spudded on 17 March 2002 from the permanent installation Gullfaks A and drilled to TD at 7725 m (2088 m TVD RKB) into the late Jurassic Viking Group. The well was drilled with OBM to TD.

It was not possible to sidetrack well 34/10-46 B before 6380 m (2017 m TVD RKB). In well 34/10-46 S/46 A/46 B the Brent Group in segment E1 and the Statfjord Formation in segment D1 were reached by the 12 1/4" section. The path of well 34/10-46 B was partly governed by well inclination restrictions in the uppermost part, and by the location of a new Cretaceous sandstone target to the west. The formation changes due to drilling into the Shetland Group, is likely to be the reason for the improper hole quality. The well proved oil down to 1993 m TVD MSL and an oil-leg of at least 5 m in the Brent Group. This oil is interpreted as an appraisal of the oil and gas from Krans Member (Kyrre Formation)/Brent Group in segment D1 in 34/10-46 A. The Brent oil is thus seen as the lower part of a 70 m hydrocarbon column on the structure. Due to a work-over operation on another Gullfaks well, the 8 1/2" section in well 46 B was temporary abandoned after the installation of the 7" liner. A 13 3/8" RTTS was set before the rig was skidded.

The extention of the well 34/10-46 B was drilled to reach a Cretaceous prospect some 1500 m to the west of the crest of segment D1. No Cretaceous