34/10-53 A

General

Well 34/10-53 S and the subsequent geologic sidetrack 34/10-53 A was drilled in the Rimfaksdalen area, a down faulted and rotated fault-block in between Rimfaks and Gullfaks Sør. The general objective for the two wells was to determine the basis for further development in the Gullfaks Sør and Rimfaks area by exploring the Rutil, Opal and Brookitt prospects. The primary target for well 34/10-53 A was to test the Middle Jurassic Brent Group Opal prospect.

Operations and results

Wildcat well 34/10-53 A was kicked off at 2147 m in well 34/10-53 S on 24 March 2011. The well was drilled with the semi-submersible installation Deepsea Atlantic. It was drilled to base of 12 1/4" section at 4592 m where it was abandoned due to a leak in the 9 5/8" liner. A technical sidetrack 34/10-53 AT2 was initiated with kick off at 1972 m and this well bore was drilled to final TD at 4855 m (3992 m TVD) in the Middle Jurassic Drake Formation. Well 34/10-53 AT2 was drilled with Versatherm oil based mud.

The Brent Group, Tarbert Formation was encountered at 4544 m (3693 m TVD), 63 m shallower than prognosed and with a slightly thinner Brent package than expected. Gas was proven in two different hydrocarbon systems with a GDT situation in Tarbert Formation proving a column of 72 m (apex to GWC) and a GWC in Ness Formation proving a column of 98 m (Ness apex-GWC). Reservoir properties were worse than expected with a much lower N/G than observed in the 34/10-53 S track. No oil shows were reported in the well.

One core was cut from 4560 to 4591 m in the Tarbert Formation. The MDT tool was run on drill pipe (TLC). A gas sample was taken at 4546 - 4556 m and a water sample at 4756.5 m.</p