ID: 360
OBJECTID: 360
wlbNpdidWellbore: 365
wlbName: 25/10-5
wlbHistory:

General

The 25/10-5 well was drilled to establish the presence of an accumulation of Eocene oil sand in the western part of the Balder Field, and evaluate the geologic concept of sand-shale distribution and reservoir quality.

Operations and results

Wildcat well 25/10-5 was spudded with the semi-submersible installation Glomar Biscay II on 15 June 1981 and drilled to TD at 2011 m in the Late Jurassic Viking Group. The well was drilled with sea water/gel/lignosulphonate.

The top of the Early Eocene reservoir was encountered at 1733 m (1708 m sub sea), as prognosed. The reservoir consisted of thin sandstone beds interbedded with shale and was oil bearing. A 49.5 m gross oil column was found down to an OWC at 1782.5 m. The net oil sandstone thickness was 18.2 m. Late Eocene Grid Formation sandstone was penetrated at 1398 m to 1443 m and Paleocene Heimdal Formation sandstone from 1905 m to 1929 m. These were both water wet without shows.

Four cores were cut in the Lower Eocene reservoir sequence. No wire line test or fluid sampling was carried out.

The well was permanently abandoned on 17 July 1981 as an oil appraisal well.

Testing

Two drill stem tests were performed in the Early Eocene reservoir. DST 1 perforated the interval 1756 m to 1753 m and produced 171 Sm3 oil/day. The oil gravity was 25.3 deg API and the gas/oil ratio was 59 m3/m3. DST2 perforated the intervals 1732 - 1740 m and 1756 - 1763 m. It produced 515 Sm3 oil/day. The oil gravity in DST2 was 25.5 deg API and the gas/oil ratio was 59 m3/m3.

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