6507/4-1

General

Well 6507/4-1 was drilled to test the Warka prospect on the Dønna Terrace in the Norwegian Sea. The primary objective was to prove reservoir presence, quality, and age (Late Albian - early Cenomanian age) of Intra Lange sandstones, and prove presence, saturation, and quality of hydrocarbons in the reservoir. A secondary objective was to test a possible deeper sand of Aptian age, the Warszawa lead.

Operations and results

Wildcat well 6507/4-1 was spudded with the semi-submersible installation Leiv Eiriksson on 12 August 2020 and drilled to TD at 4985 m in the Early Cretaceous Lange Formation. Operations on this deep well proceeded without significant problems. The well was drilled with seawater and hi-vis pills down to 817 m, with KCl mud from 817 to 1420 m, with Innovert NS oil-based mud from 1420 to 2606.5 m, with BaraECD 3.2 oil-based mud from 2606 to TD.

Three main Cretaceous sandstone sections were penetrated by the well: the Lysing Formation from 3037 to 3109 m, a K54 section from 3915 to 3971 m, and the target Late Albian Warka sandstone from 4608 to 4650 m. No Warszawa sandstones were present in the Aptian. The Warka sandstones were gas-condensate bearing with close to 39 m pay in both well tracks, the other sandstones were water bearing.

The cored Warka sandstone in the side-track had weak shows consistent with a lean gas-condensate: slow diffuse moderate yellowish to bluish white cut fluorescence, 30% weak bluish white fluorescent residue. Otherwise, there were no shows above OBM in the well.

A bypass coring side-track was made to core the Warka sandstones. This side-track, 6507/4-1 T2, was kicked off at 4386 m and TD