1/6-7

General

Well 1/6-7 is located in the Feda Graben of the North Sea, approximately mid-way between the Albuskjell and Tommeliten Gamma fields. It was drilled on the flank of a salt diapir. The primary objective of the well was to test the hydrocarbon potential of Late Jurassic sandstones. Two secondary objectives were identified; to test for hydrocarbons in the Cretaceous Chalk and to test for the development and the hydrocarbon potential of Paleocene sands.

Operations and results

Wildcat well 1/6-7 was spudded with the semi-submersible installation West Vanguard on 16 March 1992 and drilled to TD at 4995 m (5001 m logger's depth / 4925 m TVD). A 9 7/8" pilot hole was drilled from 170 to 1007m prior to the 26" section to check for possible shallow gas at 311, 351, and 397 m. No shallow gas was seen. MWD check-shots inside the 20" casing (azimuth unreliable) proved that the well had sidetracked in the 26" hole. In the 12 1/4" hole a steerable assembly was run in hole to correct the course. This twisted off, leaving a fish at 3740 m. The well was plugged back to 3550 m and the well was sidetracked from 3650 m. After the sidetrack the azimuth stayed fairly constant in a northwest direction. The inclination, though, increased. In the 12 1/4" hole from 3515 m to 4329 m the angle built from 3.73deg to 13.52deg. The angle kept building in the 8 1/2" hole until a maximum MWD survey of 31.40deg at 4701m. At this depth the bit was pulled out of the hole for an intermediate logging run and to change the BHA to an angle dropping assembly. This assembly dropped the inclination to 24.7deg by TD. At 4878 m, in the top of Sandstone Unit II, a salt water kick was taken. The well was drilled with seawater with viscous pre-hydrated bentonite sweeps down to 1007 m, with