ID: 368
OBJECTID: 368
wlbNpdidWellbore: 373
wlbName: 25/11-13
wlbHistory:

General

Well 25/11-13 was drilled to appraise the Balder Field on the Utsira High in the North Sea. The objective was to establish the presence of a thick accumulation of oil sand in the southern part of the Balder Field, and evaluate the sand-shale distribution and the reservoir quality of the Paleocene sands. Top of the Paleocene reservoir sands was anticipated at 1702 m MSL.

Operations and results

Appraisal well 25/11-13 was spudded with the semi-submersible installation Glomar Biscay II on 10 May 1981 and drilled to TD at 1932 m in the Late Cretaceous Tor Formation. The well was drilled with seawater and bentonite down to 500 m and with seawater/bentonite/lignosulphonate mud from 500 m to TD.

Shows of hydrocarbons were present in three 1-2 m thick Intra-Balder Formation sand beds between 1723 and 1743 m. The main oil-bearing Paleocene reservoir sand (Hermod Formation) was encountered between 1768.8 m to 1816.8 m. It contained oil down to the OWC at 1783 m (1758 m MSL), which is close to the regional Balder Field OWC. The average porosity in the oil zone was 33.5 %. Poorly developed 4 m thick Heimdal Formation sand was penetrated at 1858 m, and then a massive Ty Formation sandstone was penetrated from 1875 m down to the Shetland Group at 1908 m.

No cores were cut and no wire line fluid samples were taken.

The well was permanently abandoned on 29 May 1981 as an oil appraisal.

Testing

No drill stem test was performed.

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