ID: 450
OBJECTID: 450
wlbNpdidWellbore: 458
wlbName: 34/7-5
wlbHistory:

General

Well 34/7-5 is located in the Statfjord Øst area of the Northern North Sea. The primary objectives of the well were to test the reservoir potential of the Brent Group, and to determine if the oil/water contact is the same as that found in the 33/9-7 Statfjord Øst discovery well drilled to the south southwest of this well in the neighbouring block, but on the assumed same structure. A secondary objective was to test the reservoir potential of the Statfjord Formation.

Operations and results

Wildcat well 34/7-5 was spudded with the semi-submersible installation Treasure Saga on 17 January 1985 and drilled to TD at 3146 m in the Late Triassic Lunde Formation. Drilling proceeded without significant problems. The well was drilled with spud mud down to 930 m and with gypsum/polymer mud from 930 m to TD.

Trace oil shows appeared in sandstone lamina in the Cretaceous from about 2380, limestones had shows from about 2488 m. The Brent Group reservoir came in at 2502 m, approximately 60 m deeper than prognosed. Hydrocarbons were encountered in the upper section belonging to the Ness Formation. The oil/water contact could not be defined from pressure data. From shows on cores and the well logs an OWC could be placed at approximately 2521 m, in accordance with the results from well 33/9-7. Below the OWC oil shows on sandstone decreased gradually from 2523 m until they vanished at 2616 m. The Statfjord Formation was dry.

Eleven cores were cut. Cores 1 to 10 were cut from 2508 m to 2633 m in the Brent Group and the uppermost part of the Drake Formation. Core 1, from 2508 to 2510 gave no recovery. The core depths for Cores 2 to 10 were from 0.5 m to 2.2 m short of logger's depth. Core 11
wlbHistoryDateUpdated: 2016-07-06T00:00:00