Exploration wellbore: 6406/2-6
Wildcat well 6406/2-6 was spudded by the semi-submersible installation 'Deepsea Bergen' on 25 August 1998 and drilled to 5263 m, 58 m into the Early Jurassic Åre Formation. The well was a 'High Pressure High Temperature' well with max down hole temperature of 177 deg C and max pressure gradient of 1.95 g/cc in top Garn Formation (4479 m TVD RKB). Shallow gas was not encountered and operations went without major problems. The well was drilled with seawater and hi-vis pills down to 1413 m, KCl mud with glycol additive (3 - 5 % Glydril MC) from 1413 m to 2760 m, and oil based mud from 2760 m to TD. Hydrocarbons were proven in Ile and Tofte Formations, and there where good hydrocarbon indications in the Garn and Lange Formations. The main result of well 6406/2-6 was the Ragnfrid discovery with gas/condensate in Ile and Tofte Formations as proven by fluid samples and good indications of hydrocarbons in upper part of Garn Formation and in Lower Lange sandstones. No hydrocarbon fluid samples were obtained from the latter units due to poor reservoir quality. The Tilje and Åre Formations appeared to be water bearing in the well position. The Tofte Formation has good to excellent reservoir properties, Ile properties are fair to good, Garn has poor to moderate reservoir properties except for a good zone in the middle part, and the Lange sandy intervals seem to have low permeabilities.