16/2-12

General

Well 16/2-12 was drilled on the Geitungen Prospect on the Utsira High in the North Sea. The prospect is situated on a basement terrace north-west of the Johan Sverdrup Field. The main objectives were to investigate the hydrocarbon potential, reservoir quality, and lateral distribution of Intra-Draupne Formation sandstones, and the underlying sandstones of the Hugin and Sleipner Formations. The secondary objectives were to explore the hydrocarbon potential and reservoir properties in the fractured granitic Basement.

Operations and results

Well 16/2-12 was spudded with the semi-submersible installation Ocean Vanguard on 25 July 2012 and drilled to TD at 2067 m in granite Basement. There was a pre-drill shallow gas warning at 707 m, ca 100 m below 20” casing shoe, but no gas was observed when drilling. The well was drilled with seawater down to 211 m and with PerformaDril water based mud from 211 m to TD.

The well penetrated rocks of Quaternary, Neogene, Paleogene, Cretaceous and Jurassic age. No indication of hydrocarbons were recorded above top Intra Draupne Formation sandstone, which was picked at 1894 m, 12 m deeper than prognosed. The reservoir had excellent reservoir properties and contained oil. The top of the Basement was picked at 1938 m, 5 m deeper than prognosed. The fractures in the uppermost part of Basement were oil-filled. The oil/water contact was not encountered, but pressure measurements indicate a connection between this segment and the rest of the Johan Sverdrup discovery. Extensive data acquisition and sampling was carried out. The gas/oil ratio is 51.8 Sm3/Sm3 and the oil density is estimated at 0.81 g/cm3 in the Intra-Draupne reservoir.

Four cores were