ID: 639
OBJECTID: 639
wlbNpdidWellbore: 1338
wlbName: 34/8-3 A
wlbHistory:

General

Well 34/8-3 A is a sidetrack to well 34/8-3 on the A-structure on the Visund Field. Well 34/8-3 found oil and gas in the Brent Group without encountering the OWC. Well 34/8-3 A was sidetracked down flanks on the structure to establish the OWC and to test if the A-North could be in communication with the 34/8-1 A-South Discovery.

Operations and results

Appraisal well 34/8-3 A was kicked off at 944 m in the primary well on 14 November 1988. It was drilled with the semi-submersible installation Polar Pioneer to TD at 3230 m (3091 m TVD) in the Early Jurassic Cook Formation. During logging before setting of 9 5/8", the tool got stuck at 1284 m. The string was cut, and the instrument was fished. The well was drilled with KCl/polymer mud from kick-off to TD.

Spotted hydrocarbon shows were described on cuttings in the interval 2550 to 2660 m in the Kyrre Formation. Top Draupne Formation was encountered at 3003 m. Under Draupne, the sidetrack penetrated a 19 m thick Heather Formation sequence that was not present in the primary well bore. The Brent Group, Tarbert Formation was encountered at 3031 m (2900 m TVD), deeper than prognosed due to the unexpected Heather. The Brent Formation contained gas down to a gas/oil contact at 3059 m (2927 m TVD and oil down to a clear oil/water contact at 3099.5 m (2966 m TVD). Oil shows continued down to 3162 m. The Cook Formation was found water bearing. The RFT pressures in both the primary well and the sidetrack proved higher pressure in the hydrocarbon zone than on the A-South compartment, but with pressure communication in the water zone.

Five cores were cut in the interval 3034 to 3148.5 m. The drill string got stuck during cutting of
wlbHistoryDateUpdated: 2016-07-06T00:00:00