ID: 937
OBJECTID: 937
wlbNpdidWellbore: 2728
wlbName: 25/10-6 S
wlbHistory:

General

Well 25/10-6 S is located West-Southwest of the Balder field. The main objectives for the well were to prove the hydrocarbon potentials of the Heimdal, Ty, and the Hugin Formations.

Operations and results

Wildcat well 25/10-6 S well was spudded with the semi-submersible installation "Deepsea Bergen" on 26 December 1995 and drilled deviated to a TD of 4706 m (4281.5 m TVD) in the Middle Jurassic Sleipner Formation. The well was drilled using bentonite / CMC EHV mud down to 1039 m, with "ANCO 2000" mud from 1039 m to 2377 m, and with oil based "ANCOVERT" mud from 2377 m to TD. Several drilling problems were encountered below 1339 m and it took 30 days more than budget to reach TD. The problems included mud pump failure, MWD failure and difficulties with controlling the angle, bad weather, and bit problems. Many of the problems were due to hard formation. The well was drilled vertically to 1631 m before building angle.

Well 25/10-6 S drilled through sediments of Tertiary, Cretaceous and into Jurassic ages. The well penetrated the Heimdal Formation at 2317.5 m and the Ty Formation at 2636.5 m. The angle was then approximately 15.5°. The angle increased through the Shetland Group and reached a maximum of 43.5° at approximately 4330 m in the Vestland Group. The well penetrated the Hugin Formation at 4337.5 m (3995.5 m TVD), 41.5 m deeper than prognosed (at an angle of 42°). The potential reservoirs in Palaeocene sandstones (Heimdal and Ty Formations) were water bearing. The Hugin Formation contained hydrocarbons, but the core data and FMT-results showed tight formation. Three cores were cut in the Hugin Formation. Of these, a total of only 12.7 m core were recovered because a very hard formation wore out the bit earlier than expected No fluid samples were collected. The well was permanently plugged and abandoned on 22 March 1996 as a dry well with shows.

Testing

No drill
wlbHistoryDateUpdated: 2016-07-06T00:00:00