7128/6-1

General

Well 7128/6-1 is located in the Finmark East area on the Finmark Platform approximately 226 km east north east of Hammerfest. The main objective of the well was to explore a bryozoan carbonate bioherm of the Røye Formation (Kungurian- Kazanian in age). Prognosed thickness of the carbonate was in excess of 180 m. The underlying Gzelian through Artinskian carbonate succession was seen as secondary objective. A third objective was sandstones of the Billefjorden Group (Visean), but no closure had been mapped at this horizon in the prospect area. Shallow gas warning was given for one interval at 369 m.

The well is Type Well for the Tettegras, Ørn, Isbjørn, and Røye Formations and Reference Well for the Soldogg and Falk Formations.

Operations and results

Wildcat well 7128/6-1 was spudded with the semi-submersible installation Arcade Frontier on 11 August 1991 and drilled to TD at 2543 m in pre-Carboniferous Basement rocks. No shallow gas was encountered. No significant problems occurred during the drilling operation. The well was drilled with seawater and hi-vis pills down to 833 m and with KCl polymer WBS/200 mud from 833 m to TD.

Top Røye Formation came in at 1623 m. The secondary target, the Artinskian to Gzhelian limestone succession was penetrated from 1745.4 m to 2102 m. Basement was encountered at 2533.5 m. Overlying the basement is a thick sandstone sequence of Early Carboniferous age, the Soldogg Formation. Shows were recorded in limestone in the interval from 1630 m down to 2076 and in a sandstone stringer at 2176. No shows in the Soldogg Formation. A total of 24 conventional cores were cut in the carbonate sequence yielding a total of 472.4 m core. A total of 139 sidewall cores were attempted and 137 were recovered. A total of 39 formation pressure tests were attempted and three fluid samples were collected. The fluid samples were all mud filtrate. Analysis indicated normal hydrostatic formation pressure.