33/12-7

General

Well 33/12-7 was designed to drill the Delta structure, a tilted fault block on the Tampen Spur, and was the only commitment well in licence 152. The primary objective was to test the hydrocarbon potential of the Brent group on the Delta structure. A secondary objective was to explore the Statfjord Formation on the same structure. The well was designed as a possible producer in case of a discovery. Shallow gas was predicted at 375 m MSL, 415 m MSL, and possibly in sand lenses on an erosion surface at 456 m MSL.

Operations and results

Wildcat well 33/12-7 was spudded with the semi-submersible installation Deepsea Bergen on 22 February 1989 and drilled to TD at 3703 m in Early Jurassic sediments of the Statfjord Formation. After drilling 26" section to 384 m fifteen days rig time were spent trouble shooting and repairing a leak in the BOP. Otherwise operations went without significant problems. The well was drilled with seawater and gel down to 383 m, with Newdrill/PAC/seawater from 383 m to 3034 m, and with gel/lignosulphonate from 3034 m to TD. No shallow gas was encountered in the well.

Sands were encountered in the Tarbert, Rannoch, Cook and Statfjord Formations. No shows of hydrocarbons were recorded while drilling, except for some residuals in the Cook Formation. Post-well organic geochemical analyses established that the Draupne Formation has potential for generation of oil and gas and that the Heather Formation has potential for condensate/light oil and gas. Draupne is immature and Heather marginally mature in the well location. Tarbert and Cook Formations were analysed for migrated hydrocarbons but no significant abundance were found.

One core was cut in the interval 3041 m to 3057.5 m. No fluid sampling was attempted.

The well was permanently abandoned on 27 April 1989 as a dry hole.

Testing

No drill stem test was performed.