2/10-1 S

General

The 2/10-1 S "South East Eel" well is located in the Grensen Nose, close to the southern tip of the Norwegian sector. It was drilled in the Tertiary basin of the North Sea approximately 20 km south of the Embla discovery. The primary objective horizons were the Early Cretaceous - Late Jurassic clastic sediments and the Danian - Late Cretaceous limestones. Seismic data were interpreted as wedging out of the Early Cretaceous - Late Jurassic sediments up-dip to the west of the well location. These sediments produced oil in the Phillips 2/7-3 and 2/7-9 wells while Late Jurassic turbidite sands were present in the Eldfisk 2/7-1 well. In addition a small Danian/Late Cretaceous structure was defined on a seismic. The 2/7-2 well a few miles to the north in a similar geological situation produced 345 BOPD from the Danian. Secondary objectives were Tertiary and possible Rotliegendes sandstones.

Operations and results

Exploration well 2/10-1 S was spudded with the semi-submersible installation Ocean Viking on 16 September 1975 and drilled deviated to TD at 4609 m (4267 m TVD RKB) in rocks of possibly Carboniferous age. While drilling the 8 1/2" section at 4028 m the weather deteriorated. The drill string was hung off before the rig started to drift, and had to be towed to Stavanger. Winds were reported up to 30 m/s and waves up to 22 m. Altogether 34 days were lost before the rig again was on location and could continue drilling. The well was drilled with sea water and gel down to 442 m and with PAC/sea water with 4% oil from 442 m to TD.

No oil shows were encountered during the drilling, however, a gas kick was noted when drilling into the top of the Rotliegendes sandstone section. No testing was carried out due to engineering difficulties although three drill stem tests in the Permian were planned. The well was drilled as per progress down to the base of the Cretaceous sediments. No clastics were developed in the Te