1/9-5

General

Well 1/9-5 was drilled in the Feda Graben in the southern North Sea, in the saddle between the Tommeliten Gamma-structure and the intrusive salt plug forming the Tommeliten Delta structure. The purpose of the well was to appraise the Tommeliten Gamma discovery made by 1/9-4 and to test the hydrocarbon potential and reservoir quality of the Ekofisk and Tor formations.

Operations and results

Appraisal well 1/9-5 was spudded with the jack-up installation Dyvi Beta on 3 October 1978 and drilled to TD at 3450 m in the Late Cretaceous Hod Formation. The pipe got stuck at 3426 m during a clean-up trip. When trying to come loose the hook broke and the drill string dropped in the hole. This event caused material damage and rig shut-down for three days, but nobody was injured. When fishing the drill string it came loose above the jar but the rest of the BHA (approximately 260 m) was left in the hole. The well was drilled with spud mud down to 435 m, with a lime/"Morex" mud system from 435 m to 1377 m, with lime/"Morex"/Drispac mud from 1377 m to 2725 m, and with lignosulphonate/lignite mud from 2725 m to TD. A lot of hole problems occurred in the 17 1/2" and 12 1/4" sections and this was attributed to the lime/"Morex" mud system.

The Ekofisk Formation came in at 3207 m and the Tor Formation at 3282 m. No significant hydrocarbon shows were encountered in any section of the well.

One core was cut from 3215.5 to 3 233.5 m, proving a dry carbonate section. No wire line fluid samples were taken.

The well was permanently abandoned on 16 December 1978 as a dry well.