31/5-2 R

Exploration · Appraisal · P&A · Oil/gas · Saga Petroleum ASA · Troll · PL 085

31/5-2 R is an appraisal exploration wellbore in the North Sea, drilled by Saga Petroleum ASA, entered Jun 13, 1984, to 2,500 m in the Hegre Gp.

Discovery 31/2-1 (Troll Vest) · On the map →

2,500: m total depth · 2,500 m vertical
316: m water depth
Jun 13, 1984: entered · completed Aug 30, 1984
Hegre Gp: at total depth · Triassic
—: m of core
87: °C bottom-hole temperature

SODIR FACTPAGES · RECORD UPDATED NOV 4, 2026 · RELEASED AUG 30, 1986

On file for this wellbore

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

Drilling

Drilling facility: TREASURE SAGA · Semisub steel
Drilling days: 79
Kelly bushing elevation: 26 m
Maximum inclination: 2°
Drilling permit: 391-L2
Licensing round: Awarded additionally to round 7
Plugged and abandoned: Aug 30, 1984
Core samples available: No
Cuttings samples available: No
Position · ED50: 60.72591° N, 3.54798° E
Hydrocarbons in: Sognefjord Fm · Late Jurassic

Well history

WRITTEN BY THE NORWEGIAN OFFSHORE DIRECTORATE

General

Well 31/5-2 R is a re-entry of well 31/5-2. The overall purpose of these wells was to test the reservoir quality, the oil/gas columns, and the hydrocarbon/water contact in the area. The objective of the re-entry was to undertake drill stem testing of the reservoir.

Operations and results

Appraisal well 31/5-2 was re-entered (31/5-2 R) with the semi-submersible installation Treasure Saga. The rig arrived location on 10 June 1984 but due to problems with anchor handling, and on establishing 4 guidelines to well head before running BOP on riser the well was not re-entered before 13 June. After the bridge plug was retrieved at 642 m the hole was circulated with seawater and finally displaced with CaCl brine. Due to the complexity of the tests, equipment failures and an unplanned third test, the duration of the testing period was 67 days, 42 days longer than prognosed.

After testing the well was permanently abandoned on 30 August 1984 as an oil and gas appraisal.

Testing

Three drill stem tests were performed.

DST 1 tested the interval 1577 - 1581 m and produced maximum 1000 m3 oil + water /day trough a 25.4 mm choke. The GOR was 53 Sm3 /Sm3 at 10.3 bar and 60 deg C throughout the test. The corresponding WHP was 22 bar with a nitrogen injection rate of 11.5 m/min. The water production started in the beginning and increased continuously through the test. The final water cut was 62%. The oil density was 0.896 g/cm3 and the gas gravity (air = 1) was 0.66.

DST 2 tested the interval 1574 - 1576 m and produced maximum 1290 m3 oil + water/day through 44.5 + 23.8 mm choke. The GOR was 53 Sm3 /Sm3 with separator conditions of 3.8 bar and 29degC. The corresponding WHP was 15 bar. The water production started after 50 hours of flow and the water cut increased to 34%. The oil density was 0.89 g/cm3 and the gas gravity (air = 1) was 0.66.

DST 3 tested the interval 1546.5 - 1554.5 m produced

Around this wellbore

This wellbore on Sodir FactPages →

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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