ID: 569
OBJECTID: 569
wlbNpdidWellbore: 1001
wlbName: 25/1-9
wlbHistory:

General

Well 25/1-9 was drilled nearby and south of the Frigg structure close to the UK boarder, and was designed to prove possible hydrocarbon accumulation in the Frigg Formation and "Cod" sandstone (Intra Balder Formation Sandstone). A main objective was to verify the seismo-stratigraphic interpretation in block 25/1. In addition, the well was expected to obtain valuable data input to the Frigg Field reservoir simulation study. The prognosed depth was 2813 m, 50 m into the Shetland Group.

Operations and results

Wildcat well 25/1-9 was spudded with Wi1h. Wi1helmsen installation Treasure Scout 9 September 1996 and drilled to TD at 2807 m in the Late Cretaceous Hardråde Formation. Drilling proceeded without significant problems. The well was drilled with seawater and hi-vis pills down to 990 m, with KCl/polymer mud from 990 m to 1965 m, and with PAC/polymer/seawater from 1965 m to TD

The Frigg Formation was encountered at 2035 m. It consisted of very fine to fine, hard sandstones with poor reservoir characteristics down to 2051 m. From 2051 m to 2199 m the lithology was predominantly massive sandstone with excellent reservoir characteristics. Occasional stringers of claystone and what was interpreted as concretions of calcite-cemented sandstone occurred throughout the section. The lower part, from 2196 m to 2237 m was claystone with a3 m conglomerate at the base.

Hydrocarbons were encountered in the Frigg Formation with 2.6 m net pay of gas down to 2054 m and 6.9 m net pay oil down to a free water level at 2063 m. RFT pressure measurements gave an oil gradient corresponding to a fluid density of 0.81 g/cm3. Pore pressure indicated pressure depletion due to production from the Frigg Field. RFT data indicated that the Frigg Formation contains small reserves and the discovery was considered uneconomic.

The gas/oil contact was defined at 2054 m, and the oil/water contact at 2063 m. Only very weak shows we
wlbHistoryDateUpdated: 2016-07-06T00:00:00