7223/5-1

General

Well 7223/5-1 was drilled on the Bjarmeland Platform, south of the Swaen Graben, east of the Loppa High in the Barents Sea. The primary objective was to prove oil or gas in a new segment of Ladinian channel complex in the Obesum prospect. The location was chosen in order to test several plays and seismic amplitude anomalies in the Triassic Snadd and Kobbe Formations, and to avoid shallow gas anomalies.

Operations and results

A 9 7/8" pilot hole was drilled to 607 m to check for shallow gas. Some sands were penetrated, but no signs of shallow gas were seen. Well 7223/5-1 was spudded with the semi-submersible installation Polar Pioneer on 4 December 2008 and drilled to TD at 2549 m in the Early Triassic Klappmyss Formation. A leakage on the BOP control system was discovered while drilling the 12 1/4" section. The BOP and riser was pulled and repaired; this took 75 hrs. Otherwise no significant technical problem occurred. The well was drilled with seawater/CaCl2/Polymer mud down to 602 m and with Glydril WBM from 602 m to TD.

The Snadd Formation was encountered at 585 m and was 1271 m thick. The underlying Kobbe Formation was encountered at 1856 m and was 595 m thick. Hydrocarbons (gas) were observed in Snadd Formation in fluvial sandstones of Ladinian age and in the Kobbe Formation in sandstones of Anisian age. A lower Snadd Formation reservoir penetrated at 1575 m had 60 m gross sandstone with 17 m net gas bearing reservoir, but gas saturation was probably very low. Several sandstone intervals in the Kobbe Formation contained gas but the reservoirs were of very poor quality. Oil shows in the form of fluorescence were recorded at several levels in the Kobbe Formation.

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