2/8-2

General

Exploration well 2/8-2 is located about 8 km south of the 2/5-3 Sørøst Tor Discovery. Danian and Maastrichtian limestones were the main objectives. Another objective was to investigate if the Paleocene hydrocarbon bearing sandstones, which had been encountered in the Cod Field, extend across the 2/8-2 location.

Operations and results

Well 2/8-2 was spudded with the jack-up installation Orion on 28 June 1970 and drilled to TD at 3245 m in the Late Cretaceous Rødby Formation. While drilling at approximately 1774 m large chunks of clay came over the shale shaker, followed by a gas kick at 1777 m. The mud weight was reduced to 10.0 ppg and degasser was run for two hours. Then the weight was increased to 14.1 ppg, the hole circulated and drilling continued. Sloughing of shale occurred around 2490 m, and the mud weight was increased to 14.3 ppg to control this problem. TD was reached and the well successfully logged. Seawater was used for drilling the 36" hole down to 129 m. A seawater/ gel mud was used to drill out the 36" casing and down to 427 m. From 427 m to TD the well was drilled with an Emulsite/Drill aid system with 2 to 5 % diesel oil added.

Only traces of sandstone and siltstone were encountered in the Paleocene section, and the rocks showed no indications of hydrocarbons. Neither the Danian sequence, which was thinner than expected, nor the Maastrichtian limestones contained hydrocarbons. The only significant hydrocarbon shows encountered in 2/8-2 were from thin dolomite and limestone stringers of Eocene age. These exhibited good oil stains but generally showed poor porosities, and further evaluations were not made. Two cores were cut in the well. Core l from 2962 m to 2971 m recovered 9 m of Danian chalk and core 2 from 3231 m to 3238 m recovered 6.4 m of Rødby Formation shale. No fluid sample was collected from the well.

The well was permanently abandoned on 30 July as a well with shows