36/1-2

General

The exploratory well, 36/1-2, was drilled on Block 36/1 in the northern Norwegian North Sea approximately 25 km west of Måløy in western Norway, east of the Norwegian Trench. The primary target of well 36/1-2 was possible hydrocarbon bearing sandstones of the Middle and Late Jurassic. The secondary target was possible hydrocarbon bearing Early Cretaceous sandstones. The geological sequence on East Greenland shows favourable sand developments in the Lower Cretaceous and similar depositional configurations might exist in the 041/042-license area.

Operations and results

Wildcat well was spudded with the semi-submersible installation Deepsea Saga on 26 August 1975 and drilled to TD at 3255 m in metamorphic gneiss basement. No significant problems were encountered during operations. The well was drilled with salt-water gel mud down to 650 m, with gypsum mud from 650 m to 1406 m, and with lignosulphonate mud from 1406 m to TD.

The secondary target Early Cretaceous sandstone (Agat Formation) was encountered from 2815 m to 2865 m. The primary target Jurassic sandstones were found to be Intra Heather Sandstone, from 3146 m to top of the basement at 3233 m. No hydrocarbons were found on logs, but shows, often characterized as "tary dead oil", were encountered from 2330 m in the Late Cretaceous Tryggvason Formation down to 3192 m in the Late Jurassic Intra Heather sandstone. The strongest shows were recorded in silty sandstone of the Agat Formation from 2815 m to 2825 m, described in well reports as " light brown stain, pale yellow fluorescence and weak, white, streaming cut, accompanied by traces of oil in mud."

One conventional core was cut over the interval 2987.4 m to 3005.8 m with 100% recovery. The core was taken on sand indication in middle Jurassic, but the recovered core consisted of shale with a thin stringer of tight siltstone. Five FMT samples were attempted in the interval 3154.5 m to 31