35/9-11 S

General

Well 35/9-11 S was drilled to appraise the 35/9-6 Titan discovery on the northern tip of the Ryggsteinen Ridge, west of the Gjøa Field. The 35/9-6 Titan Discovery had encountered oil and gas at five stratigraphic levels: in Intra Heather Formation sandstones of Callovian age and in the Tarbert, Etive, Drake and Cook formations. The35/9-11 S well was drilled down-flank of the discovery well in order to prove up additional HC volumes and reduce the resource uncertainty. Well 35/9-11 S was drilled to verify the discovery in 35/9-6. If hydrocarbons are verified a sidetrack (35/9-11 A) was planned to perform necessary data acquisition.

Operations and results

Appraisal well 35/9-11 S was spudded with the semi-submersible installation Leiv Eiriksson on 1 March 2014 and drilled to TD at 3800 m (3733 m TVD) in the Early Jurassic Amundsen Formation. A 9-7/8 pilot hole was drilled from 463 m to 785 m to check for shallow gas and to identify a casing point in the Lark shale. No shallow gas was seen. Operations went forth according to planned schedule apart from minor NPT connected to trouble with the 13 3/8" wear bushing and junk in hole before proceeding with the 12 1/4" section. The well was drilled with spud mud down to 464 m and with Glydril mud from 464 m to TD.

The Oxfordian and Callovian Intra Heather sandstones were absent in 35/9-11 S. The Tarbert, Etive and Cook formations were intersected. From CPI log hydrocarbons were confirmed in all three formations and core points were selected for the discovery case appraisal sidetrack.

Wire line logs were run in 35/9-11 S. However all sampling and coring was to be done in the A sidetrack.

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