ID: 722
OBJECTID: 722
wlbNpdidWellbore: 1644
wlbName: 25/1-8 SR4
wlbHistory:

General

The Frigg Field was discovered by well 25/1-1 in 1971 and set in production in May 1977. Well 25/1-8 S was drilled in the summer of 1985 to monitor changes in gas/fluid contact, uncover permeability barriers and pressure gradients in the Frigg Formation, refine the geological model, and provide ties for seismic interpretations. Before production started the Frigg Field fluid contacts were: OWC = 1955.9 m TVD MSL and GOC = 1948.2 m TVD MSL. In July 1985 in 25/1-8 S found the oil-leg to be all swept with the exception of a very thin oil-layer lifted to 1903.5 m TVD MSL, 2 m below the new gas/liquid contact, which was now a gas/water contact (GWC) at 1901.3 m TVD MSL. The objective of the fourth re-entry well 25/1-8 SR4 was to monitor further changes in the GWC and to permanently plug and abandon the well.

Operations and results

Appraisal well 25/1-8 S was re-entered (25/1-8 SR4) with the semi-submersible installation West Vanguard on 3 April 1991.

The GWC was found at 1897.5 m TVD MSL, the same as in 25/1-8 SR3. This showed a similar situation as in well 25/1-7 and corresponding re-entries ca 2.5 km to the north. It showed that gas drainage was blocked by shale barriers over large areas in the central parts of the field.

No cores were cut. The RFT was run, and 6 pressure points were taken but no fluid samples.

The well was permanently abandoned on 14 April 1991 as a gas appraisal well.

Testing

No drill stem test was performed.

wlbHistoryDateUpdated: 2026-02-24T00:00:00