35/6-2 S

General

Well 35/6-2 S was drilled on the Måløy Slope in the Northern North Sea, in the block just north of the Gjøa field and the 35/9-3 Discovery. The main objectives were to prove hydrocarbons in the Early Cretaceous Grosso prospect and the Late Cretaceous Silius prospect. It is a replacement well for well 35/6-1 S, which was abandoned due to a shallow water flow.

Operations and results

A 12 1/4" pilot well (35/6-U-1) was spudded with the semi-submersible installation Ocean Vanguard 10 February 2009 and drilled to 585 m, the expected TD of 20" casing in the new well 35/6-2 S, in order to check for high pressure shallow water. The pilot well was flow checked and no flow was seen. Wildcat well 35/6-2 S was spudded on 4 February 2009 and drilled to TD at 3700 m (3583 m TVD) in Hauterivian aged sandstones within the Cromer Knoll Group where drilling was terminated due to hole problems. The well path was vertical down to ca 1830 m. From there the deviation angle increased up to maximum 33.6 deg at 2800 m and dropped of to ca 9 deg at TD. The well was drilled with seawater and hi-vis pills down to 585 m, with Performadril water based mud with 2.5 - 5% glycol from 585 m to 1662 m, and with Spec 12c yellow oil based mud from 1662 m to TD.

The well penetrated rocks of Quaternary, Tertiary and Cretaceous age. The well encountered the Silius reservoir at 2195 m (2190.2 m TVD) and the extensive Grosso sandstones (Agat Formation) at 3015 m (2931 m TVD). Both reservoirs were water wet. A third sand-prone interval from 3500 m to 3700 m (TD) was penetrated. This interval was dated as earliest Late Hauterivian to Early Hauterivian and is therefore of age-equivalence to the Ran Sandstone Units of the Åsgard Formation. No shows were record