ID: 975
OBJECTID: 975
wlbNpdidWellbore: 2993
wlbName: 35/4-1
wlbHistory: General

Well 35/4-1 was committed to test the hydrocarbon potential of Jurassic sandstones. The main target was the Brent Group. The Cook and Statfjord Formations were secondary targets. In addition the well should establish a good seismic tie.

Operations and results

Well 35/4-1 was spudded with the semi-submersible rig "Treasure Saga"on 24 December 1996 and reached TD on 30 April 1997 at a depth of 4936 m in the Triassic Hegre Group, fulfilling the objectives of the target depth. Including an expanded coring programme the activities lasted for 155 days, some 63 days behind the original budget. The main contribution for the budget overrun were bad weather conditions, technical problems in the well, technical problems for the drilling contractor, slow penetration rate in the lower sections section and a comprehensive plug and abandonment programme. The well was drilled water based to 3138 m (bentonite to 1362 m and ANCO 2000 mud from 1362 m to 3138 m) and oil based (ANCOVERT) from 3138 m to TD.

The well was found to be dry with weak hydrocarbon shows from the Eocene throughout the entire underlying section and into the Statfjord Formation. The well encountered sands within the Eocene, Dunlin Group and Statfjord Formation. The Brent Group, which was the primary target, contained mostly silts and very little sands of reservoir quality. High formation pressure was detected from the upper part of the Cretaceous to TD with a maximum of 1.84 rd recorded in the Brent Group.

Seven cores were cut in the interval 4084 m to 4266 m in the Brent Group and two cores in the Lower Jurassic (4447 m to 4475 m and 4709 m to 4737 m). The well was plugged and abandoned as a well with shows.

Testing

No drill stem test was performed.

wlbHistoryDateUpdated: 2016-07-06T00:00:00