16/1-17

General

Well 16/1-17 was drilled on the Jorvik Prospect on the Utsira High, about 5 km east of 16/1-8, the discovery well on the Edvard Grieg field. The objective of the well was to prove petroleum in Pre-Jurassic sandstone and conglomerate rocks.

Operations and results

Wildcat well 16/1-17 was spudded with the semi-submersible installation Transocean Winner on 9 January 2013 and drilled to TD at 2070 m in granitic Basement rock. Due to shallow gas warnings, a 9 7/8" pilot hole was drilled to 610 m. No shallow gas was observed. Operations proceeded without significant problems. The well was drilled with seawater and high viscosity pills down to 615 m and with Glydril water based mud from 615 m to TD. Geochemical analyses of cuttings and cores show traces of diesel-like hydrocarbons in the mud.

A conglomeratic/sandy section was penetrated from 1869 m to top basement at 1987 m. Poor dating suggest the section to belong to either the Triassic Hegre Group, or the Permian Rotliegend Group. The cores show oil in the conglomeratic part of this section between 1882 m and 1952 m. The shows correspond to increased gas readings on the logs. Moveable oil was sampled here, at high drawdown in tight formation, but no fluid gradients were established. The uppermost part of the basement, 1987.45 to 1993.5 m core was covered by core #5. This is an extremely weathered felsic basement. No granitic wash or regolith was observed in core at the top of the interval. Pressure measurements in the water filled fractured basement indicate a pressure regime analogous to the Edvard Grieg field and the 16/1-12 discovery.

Five cores were cut covering the interval from 1856 m in the Early Cretaceous, throug