35/11-22 S

General

Well 35/11-22 S was drilled to test the Bergand prospect in on the Lomre Terrace about 10 kilometres west of the Fram field in the North Sea. The primary exploration objective for well 35/11-22 S was to prove oil in Middle to Early Jurassic reservoir rocks of the Brent Group and the Cook Formation (Dunlin Group). The secondary exploration objective was to prove oil in the Statfjord Group in the Early Jurassic.

Operations and results

Wildcat well 35/11-22 S was spudded with the semi-submersible installation Deepsea Bergen on 12 December 2018 and drilled to TD at 3882 m (3866 m TVD) in the Early Jurassic Statfjord Group. Drilling at 2503 m there was a gas influx, believed to come from a thin sandstone in the Shetland Group. The gain was killed by raising the mud weight from 1.25 to 1.32 sg. Otherwise operations proceeded without significant problems. The well was drilled with seawater and hi-vis pills down to 429 m, with KCl mud from 429 m to 1207 m, and with Innovert oil-based mud from 1207 m to TD.

A 30 m thick Oxfordian to Early Kimmeridgian age Intra Heather sandstone was encountered at 3030 m (3026 m TVD), directly underlying the Draupne Formation. Fluid sampling indicated oil all through this sandstone. No oil/water contact was established. In the primary exploration target, the well encountered the Brent Group with a thickness of about 190 metres, of which 90 metres of effective reservoir rocks with moderate reservoir quality. The thickness of the Cook Formation is about 70 metres, of which 50 metres of effective reservoir rocks with poor to moderate reservoir quality. Both primary targets are water-bearing. The secondary exploration target, in the Statfjord group, has a thickness of about 130 metres, of which 60 metres of