34/8-18 S

General

Well 34/8-18 S was drilled on a highly tilted fault block downfaulted east of the Visund Main Field on Tampen spur in the North Sea. The primary objective of the well was to prove petroleum in the Telesto prospect in Early Jurassic reservoir rocks (the Statfjord group).

Operations and results

Wildcat well 34/8-18 S was drilled from the Visund platform, as a side-track to oil producer 34/8-A-36 H. It was kicked off below the 9 5/8” shoe at 3619 m in the Shetland Group on 9 February 2019. It was drilled with an 8 1/2” bit, in one bit run, all through to TD at 6068 m (3327 m TVD) m in the Late Triassic Lunde Formation. The well was drilled highly deviated (ca 87° inclination through most of Shetland Group). Operations proceeded without significant problems. The well was drilled with RheGuard oil-based mud from kick-off to TD.

The well drilled ca 3 km of Shetland Group before Cromer Knoll came in at 5679 m and a thin Viking Group at 5692 m. The whole of Brent Group and the upper part of the Dunlin Group was eroded in-well. Top Statfjord Group was penetrated at 5769 m (3082 m TVD). The well encountered a gross oil column of about 115 metres in the upper and lower part of the Statfjord group, with effective reservoir of 17 and 20 metres, respectively, in sandstone mainly with moderate reservoir quality. Pressure data showed initial pressure in the reservoir sands, but the HC filled reservoir in the lower Statfjord had slightly higher pressure (ca 5 bar) than the upper Statfjord. Observations showed a contact in upper Statfjord at 5849 m (3139 m TVD), and an oil-down-to/water-up-to at 5916.5/ 5925 m (3193/3200 m TVD) in lower Statfjord . In the upper part of the Lunde formation, about 15 metres of water-bearing sandstone with poor res