ID: 395
OBJECTID: 395
wlbNpdidWellbore: 400
wlbName: 31/4-1
wlbHistory:

General

Well 31/4-1 is located on the Brage Horst between the Oseberg and Troll Fields in the Northern North Sea. The primary objective was Middle Jurassic sandstones of the Brent Formation. A "flat-spot" was seen on the seismic sections and tentatively interpreted to represent a gas fluid contact in these sandstones. A secondary objective was sandstones in the Early Jurassic Statfjord Formation. Sandstone intervals of upper Early Jurassic age (Dunlin Formation) and of Triassic age (Hegre Group), were also expected to be penetrated, but were not considered to be prospective. The well was planned to be drilled to a depth of 2930 m RKB (+/- 90 m), 100 m into the Triassic.

Operations and results

Well 31/4-1 was spudded with the semi-submersible installation Norskald on 9 September 1979 and drilled to TD at 1000 m in Late Oligocene - Miocene sediments of the Hordaland Group.

None of the objectives were tested due to technical problems; the well was plugged and abandoned due to lack of cement support around the 30" casing, experienced when landing the 20" casing. No cores were cut and no wire line fluid samples were taken.

The well was permanently abandoned on 25 September 1979 as a junk well. The rig was moved over 100 - 150 m in a direction 213 degree N to spud replacement well 31/4-2.

Testing

No drill stem test was performed.

wlbHistoryDateUpdated: 2016-07-06T00:00:00