34/5-1 A

General

The 34/5-1 A exploration sidetrack was planned to test an eastern segment of the Blåbær prospect in Tampen North, ca 9 km to the southwest of the 34/3-1 S Jordbær discovery. The primary well bore 34/5-1 S well proved a hydrocarbon bearing column within the Cook Formation in 64 m TVD of interbedded sandstones and siltstones, and the Cook Formation was the target for the sidetrack as well.

Operations and results

Appraisal well 34/5-1 A was drilled with the semi-submersible installation Bredford Dolphin. It was kicked off on 16 March 2010, at 2137 m from primary well 34/5-1 S and drilled to TD at 4416 m (3731 m TVD) in the Early Jurassic Burton Formation. No significant problems were encountered in the operations. The well was drilled with XP-07 oil based mud from kick-off to TD.

Top Cook Formation (Late Pliensbachian) reservoir came in 27.6 m shallower than the prediction at 4274 m (3602 m TVD). The Cook Formation sandstones had an average porosity of 18.3% and 20 m of net sand based on 50% Vsh cut-and 10% porosity cut-off. As in 34/5-1 S the Upper and Lower Cook had markedly different reservoir properties. Generally the reservoir properties of the 34/5-1 A were worse than the well 34/5-1 S in both units. A very weak residual(?) show was observed in a sandstone sample at 4275 m. Otherwise, no hydrocarbon shows were observed in the well. Mudstone in the lower part of the Drake Formation showed source rock properties with elevated gamma ray above 150 deg API, TOC around 2 %wt, and average Hydrogen Index around 300 with peak HI up to 450 mg HC/g TOC.

Due to dry well no cores were cut and no wire line fluid samples were taken.

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