ID: 4
OBJECTID: 4
wlbNpdidWellbore: 5
wlbName: 34/10-17
wlbHistory:

General

Well 34/10-17 was the first well drilled on the Beta structure in the SE segment of block 34/10, south-west of the Alpha-structure, which contained the Gullfaks Sør Field. The primary objective of the well was to evaluate possible hydrocarbon accumulations in the Middle Jurassic Brent sandstones. The secondary objectives were the Early Jurassic Dunlin and Statfjord sandstones.

Operations and results

Wildcat well 34/10-17 was spudded with the semi-submersible installation Deepsea Bergen on 22 February 1983 and drilled to TD at 3466 m in the Early Jurassic Statfjord Formation. The well was drilled down to 2687 m without special drilling problems. At 2687 m a heavy flow was observed after a drilling break. The well was shut in, and due to a plugged cement hose and kill line failsafe valve, about 200 hours were used to circulate out the influx, stabilize, clean up and condition the hole. Further technical failure and tight hole caused extensive time logging the 6" section, and the logging programme was reduced. The well was drilled with Seawater/gel spud mud down to 668 m and with seawater/gel/Lignosulphonate mud from 668 m to TD.

The Brent Group was encountered at 2685 m with hydrocarbon bearing sandstones in the Tarbert and Ness Formations. FMT pressures indicated a gas/oil contact at ca 2862 m, and an oil/water contact at ca 2914 m in the lower part of the Ness Formation. The logs indicated a total oil and gas net pay of 122.5 m with average porosity 22.5% and average water saturation 27%. Also the underlying water bearing Etive and Rannoch Formations of the Brent Group had good reservoir quality sandstones. The Dunlin and Statfjord sandstones were water bearing. Shows were recorded on cores down to 2947.5 m in the Ranno
wlbHistoryDateUpdated: 2016-05-19T00:00:00