NORWAY · WELLBORES · NPDID 478

30/9-5 S

Exploration · Wildcat · P&A · Gas · Norsk Hydro Produksjon AS · Oseberg Sør · PL 104

9 documents: reports, logs, and plots →

30/9-5 S is a wildcat exploration wellbore in the North Sea, drilled by Norsk Hydro Produksjon AS, entered May 27, 1985, to 2,980 m in the Hegre Gp.

Discovery 30/9-5 S Oseberg Sør · On the map →

2,980
m total depth · 2,963 m vertical
103
m water depth
May 27, 1985
entered · completed Jul 19, 1985
Hegre Gp
at total depth · Late Triassic
35.5
m of core in 2 cores
85
°C bottom-hole temperature

SODIR FACTPAGES · RECORD UPDATED NOV 4, 2026 · RELEASED JUL 19, 1987

On file for this wellbore

What the Directorate holds from this wellbore. Each opens the section that lists it.

Drilling

Drilling facility
TREASURE SEEKER · Semisub steel
Drilling days
54
Kelly bushing elevation
25 m
Maximum inclination
12.30000019°
Drilling permit
467-L
Licensing round
9
Plugged and abandoned
—
Core samples available
Yes
Cuttings samples available
No
Position · ED50
60.35871° N, 2.89364° E
Hydrocarbons in
Cook Fm · Early Jurassic

Well history

WRITTEN BY THE NORWEGIAN OFFSHORE DIRECTORATE

General

Well 30/9-5 S was drilled on the "J" prospect close to the western margin of the Horda Platform. The structure is bounded by Jurassic strata dipping down into the north, east and south and by the main Horda Platform fault to the west. The primary objective was to prove hydrocarbon accumulation in the Etive Formation of the Brent Group. Secondary objectives were possible hydrocarbons in sandstones if present in the Heather-Drake- and Cook Formations.

Operations and results

Wildcat well 30/9-5 S was spudded with the semi-submersible installation Treasure Seeker on 27 May 1985 and drilled to TD at 2980 m (2963 m TVD) in the Triassic Hegre Group. Due to shallow gas indications on the site survey seismic the well location was moved approximately 150 m. The well was then deviated from a kick off point at 1000 m to reach the planned target. No significant problem was encountered in the operations. The well was drilled with seawater and gel down to 910 m, with KCl/polymer mud from 910 m to 1935 m, and with NaCl/polymer mud from 1935 m to TD.

The well encountered a gas bearing Cook Formation and minor amounts of gas in the Brent Group. No additional hydrocarbon bearing reservoirs were encountered by the well.

The Brent Group (2236-2253 m, 2222-2239 m TVD) was found severely eroded in the well with poorly developed sands. The net sand distribution is limited to a thin layer at the top of the formation. The rest of the formation appears to be very silty. The gross thickness is 17 m with a net pay of only 0.5 m. The average porosity is 20.2% and the water saturation 58.2%. The Cook Formation (2447-2466 m, 2433-2452 m TVD) has moderately good reservoir qualities in the upper p

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About this data

Norwegian Offshore Directorate (Sodir) FactPages, mirrored nightly and used under the Norwegian Licence for Open Government Data (NLOD). Depths are metres along the wellbore from the kelly bushing unless a row gives its own unit; older cores are filed in feet. A zero the Directorate files for an unmeasured pressure, density, or temperature is shown as a dash.

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