10/8-1

General

The 10/8-1 well is situated close to the Lista Nose in the eastern part of the Norwegian-Danish Basin. It was drilled on a salt induced anticlinal structure related to a salt pillow. The structure is well defined from the Permian salt up to the upper cretaceous chalk. It has a vertical closure of 300 m for a closed area of 80 km2 at a seismic horizon assumed to be the Jurassic sandstone. A fault cuts the unconformably underlying horizons attributed to Triassic. The specific objective of the 10/8-1 well was to test the hydrocarbon potential of the Jurassic sandstone section, estimated to be 60 m thick, with additional reservoir being furnished by the Triassic sandstones immediately below.

The well is Type Well for the Skagerrak Formation and Reference Well for the Smith Bank Formation

Operations and results

Wildcat well 10/8-1 was spudded with the semi-submersible installation Pentagone 81 and drilled to TD at 2861 m in the Late Permian Zechstein salt deposits. The well was completed in 37 days without reported problems. The well was drilled with seawater with returns on the sea floor down to 510 m, and with a LFC/sea water mud system from 510 m to TD.

One thousand three hundred meter of continental deposits of Triassic age is present. On top of this is the Gassum Formation. The Early to Middle Jurassic was not encountered in the well. One hundred and fifty meter Late Jurassic sand and shale is directly overlying the Gassum Formation. Around 200 m of shale was deposited during the Early Cretaceous while the Late Cretaceous is represented by 425 m of lime mudstones. The lower 200 m of the Tertiary was developed in mostly sandy facies. All Formations penetrated by the well were found water wet. The only show recorded was traces of gas (C1 and C2) from 1010 m to 1050 m. Organic geochemical screening analyses show TOC in range 0.1 - 1.5 % with the highest values in the Late Jurassic and Cretaceous sequences. The Tr