ID: 435
OBJECTID: 435
wlbNpdidWellbore: 442
wlbName: 34/7-3
wlbHistory:

General

Well 34/7-3 was drilled on the Snorre E structure in the northern part of block 34/7. The purpose was to further appraise the reservoir potential of the Statfjord Formation and upper Lunde Formation in the E-structure extension of the Snorre Discovery and to test the oil/water contact found in wells 34/4-4 and 34/7-1.

Operations and results

Well 34/7-3 was spudded with the semi-submersible installation Vildcat Explorer on 14 September 1984 and drilled to TD at 3414 m in the Late Triassic Lunde Formation. Drilling proceeded without significant problems. The well was drilled with spud mud down to 454 m, with gel mud from 454 m to 1165 m, with KCl/Polymer mud from 1165 m to 2769 m, and with ligno/lignosulphonate mud from 2769 m to TD.

The well consisted mainly of claystones in the Tertiary and Cretaceous sections, with the exception of sand development in the Utsira Formation (Miocene), and an Early Oligocene sand development (1288 - 1323 m). The rest of the well, the Jurassic and Triassic sections, was mainly composed of alternating claystone/sandstone sequences. Top Statfjord was encountered at 2414 m.The Statfjord and Lunde Formations were oil filled down to a common OWC at 2610 m based on pressure gradients. Strong shows on cores continued down to 2622 m, below this depth the shows became weak and spotted. Apart from this oil shows, of variable quality, started in silty claystones at 2180 m in the Late Cretaceous and continued down to 2755 m in the Lunde Formation.

A total of 19 cores were taken in the interval 2396 - 2643 m in the Jurassic (Dunlin- and Statfjord Formations) and the Triassic sequence (Upper Lunde Formation). The core recovery was 91.5%. Core depth for core
wlbHistoryDateUpdated: 2018-03-16T00:00:00