17/8-1

General

Well 17/8-1 was drilled to test the Dovregubben prospect on the Sele High in the North Sea. The primary objective was to seek hydrocarbons in Middle Jurassic Sandnes Formation sandstones and establish its reservoir facies and quality. The secondary objective was to seek hydrocarbons in Permian Zechstein carbonates and/or Rotliegend clastics and establish their facies and quality. A third objective was to drill a section of the underlying Paleozoic stratigraphy to establish its facies and possible prospectivity.

Operations and results

A 9 7/8" shallow borehole 17/8-U-1 was drilled to check for shallow gas. It was drilled simultaneously with the top-hole sections of well 17/8-1 in a dual-drilling operation. The surface location of the shallow borehole was offset 10 m from the 17/8-1 location. No indication of shallow gas or shallow water flow was observed.

Wildcat well 17/8-1was spudded with the semi-submersible installation Deepsea Stavanger on 16 September 2021 and drilled to TD at 2921 m in undifferentiated Paleozoic clastics. Operations proceeded without significant problems. The well was drilled with seawater and hi-vis pills down to 1005 m, with Rheguard Prime oil-based mud from 1005 m to 2343 m, and with Glydril Plus mud from 2343 m to TD.

The well encountered 18 metres of the Sandnes and Bryne formations from the Middle Jurassic, 10 metres of which comprised sandstone with good reservoir quality. In the secondary exploration target, the well encountered about 70 metres of tight carbonate rocks in the Zechstein Group, which rest unconformably on dipping Paleozoic clastics below. Eighty-four metres of tight conglomerates, sandstone and claystone were drilled below this