8/10-4 B

General

Well 8/10-4 B is a sidetrack to well 8/10-4 S on the Butch prospect, a salt induced structure on the Sørvestlandet high in the North Sea. After discovering a full oil column in Well 8/10-4 S and establishing the local OWC in well 8/10-4 A, it was decided to drill the sidetrack 8/10-4 B to evaluate the south-western segment of the Butch prospect, via a relatively long, high angle sidetrack. The Ula Formation target was located at 3354 m (2600 m TVD MSL), along a vertical section of approximately 1430 m from the kick-off point.

Operations and results

Well 8/10-4 B was drilled with the jack-up installation spudded with the semi-submersible installation Mærsk Guardian. It was kicked off on 22 December from the parent well, 8/10-4 S at 1038 m, approximately 37 m below the 13 3/8" casing shoe. The well experienced borehole stability problems after drilling 113 m with only minimal kick-off from the parent well. This attempt was abandoned and a new sidetrack, Well 8/10-4 B T2 was initiated by successfully milling through the 13 3/8" casing at 847 m. The well was drilled to 2549 m in the basal Hordaland Group with frequent borehole stability problems. After performing a problematical wiper trip, the lowermost part of the BHA was lost in hole and the well was abandoned without reaching the target reservoir level.

No cores were cut and no wire line fluid samples were taken.

The well was permanently abandoned on 2 January 2012 as a junk well.

Testing

No drill stem test was performed.

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