17/12-2

General

Well 17/12-2 is located on the northwestern margin of the Egersund Basin in the North Sea, ca 14 km southwest of the 17/12-1R Discovery. The primary objective was to test Middle Jurassic and/or Triassic sands. Both had been found present in the 17/12-1R well where the Middle Jurassic sand was oil-bearing (Bream Discovery). The Triassic sands could be oil-bearing, especially if overlain by Jurassic shale. A secondary objective was seen in the Late Cretaceous limestones. Planned TD was at 3658 m (12000 ft) or 100 m into Zechstein salt.

Operations and results

Wildcat well 17/12-2 was spudded with Ocean Viking on 31 August 1973 and drilled to TD at 2334 m in Devonian sand.

No shows were present in the Late Cretaceous Limestone. An oil-bearing Jurassic sand 13 m thick (7 m net pay) was encountered at 2157 m. The Triassic was absent and the Jurassic Sandnes and Bryne Formations rested directly on a 50 m thick layer of Permian salt at 2243 m. Below the salt was a 7 m thick Rotliegendes sequence. Sandstone of possible Devonian age was encountered at 2300 m. This remnant Paleozoic feature caused the well to be terminated higher than originally anticipated.

One conventional core was cut at TD from 2330.8 m to 2333.9 m. No wire line fluid samples were taken.

The well was permanently abandoned on 9 October 1973 as an oil Discovery.

Testing

Two drill stem tests were carried out. DST1 from 2166 m to 2169 m produced 16 m3 water cushion and 1 m3 oil. After the final flow period water cushion and formation fluid was reversed out. DST2 from 2157 m to 2162 m produced at maximum 366 m3 oil and 31800 m3 gas / day. Gas-oil ratio was 87 m3/m3 and oil gravity was 27.9 °API.