16/1-31 A

General

Well 16/1-31 A was drilled in the northern margin of the Edvard Grieg Field on the Utsira High in the North Sea. The primary objective was to appraise the reservoir quality, fluid properties, hydrocarbon potential and productivity of potential reservoir rocks on the eastward continuation of the Edvard Grieg basement high.

Operations and results

Appraisal well 16/1-31 A was spudded with the semi-submersible installation Leiv Eiriksson on 11 May 2019 and drilled to TD at 2650 m (2002.6 m TVD) m in granitic basement rocks. Operations proceeded without significant problems. The well was drilled with seawater and hi-vis pills down to 1404 m, with Innovert oil-based mud from 1404 m to 2267 m, and with Baradril N water-based mud from 2267 m to TD.

The Tellus East appraisal well encountered a gross oil column of 60 metres in porous, weathered basement reservoir. Top reservoir was encountered at 2350.1 m (1874.8 m TVD). The oil/water contact is estimated to be between 2492 and 2497 m (1935 and 1937 m TVD). No oil shows were observed above top reservoir. Partly continuous shows with petroleum odour, stain, cut, and direct fluorescence were seen in basement down to 2390 m. Below this depth sporadic shows were observed with direct and cut fluorescence, but without odour or stain down to 2460 m.

Three cores were cut in succession from 2357 to 2369.05 m with 85% total recovery. MDT pressure data indicated ca 4 bars depletion relative to the 16/1-13 Edvard Grieg well. MDT fluid samples were taken at 2351.51 m (oil), 2362.01 m (water), 2389.5 m (oil), 2410.4 m (oil), 2452.71 m (oil), 2492.70 m (oil and water), 2497.68 m (water), 25