ID: 359
OBJECTID: 359
wlbNpdidWellbore: 364
wlbName: 25/8-3
wlbHistory:

General

Well 25/8-3 was drilled in the northern part of the Utsira High in the North Sea. The main purpose was to establish the presence of a thick accumulation of Paleocene oil sand, and evaluate the Paleocene sand-shale distribution and reservoir quality in the area. The top of the reservoir was anticipated to be at 1668 m subsea.

Operations and results

Wildcat well 25/8-3 was spudded with the semi-submersible installation Glomar Biscay II on 20 March 1981 and drilled to TD at 1868 m in the Danian Ekofisk Formation. A total of 159.25 hours, or more than 23% of the total time spent on this well, were lost due to downtime in the categories of: Subsea and Surface BOP Equipment Repairs and Casing and Wellhead. The well was drilled seawater and hi-vis pills down to 219 m and with seawater/gel/Lignosulphonate from 219 m to TD.

The top of the Paleocene reservoir (Hermod Formation) was encountered 64.5 m lower than predicted at 1757.5 m and the net oil sand was 9.5 m thick, which is close to what was found in the 25/8-1 well to the southwest. The results were disappointing as there was much less sand than had been anticipated. However, shows of hydrocarbons were found in thin sand stringers throughout the interval 1667-1784 m, suggesting that the OWC might be at 1784 m (1759 m TVD SS), about the same as in the Balder field.

One core was cut from 1859 m to 1868 m in the Ekofisk Formation Chalk/Limestone and recovered 90%. Reservoir data was limited to mud logs and electric logs. No wire line fluid samples were taken.

The well was permanently abandoned on 17 April 1981. It is classified as an oil appraisal of the 25/8-10 S Ringhorne
wlbHistoryDateUpdated: 2016-07-06T00:00:00