6604/5-2 S

General

Well 6604/5-2 S was drilled to appraise the 6604/5-1 Balderbrå discovery in the Vøring Basin of the Norwegian Sea. The primary objective was to verify continuation of reservoir and presence of hydrocarbons in the Late Cretaceous Springar Formation.

Operations and results

Appraisal well 6604/5-2 S was spudded with the semi-submersible installation Scarabeo 8 on 22 January 2020 and drilled to TD at 4155 m (3849.7 m TVD m in the Late Cretaceous Springar Formation. Operations proceeded without significant problems. The well was drilled with seawater and hi-vis pills down to 2328 m and with Innovert NS oil-based mud from 2328 m to TD.

Three separate Springar sandstone units were penetrated: Sandstone 1 from 3645.4 to 3652.4 m (3386.9 to 3391.3 m TVD), Sandstone 2 from 3777.5 to 3853.4 m (3508.2 to 3577.2 m TVD), and Sandstone 3 from 3935.1 to 4082 m (3651.3 to 3784 m TVD). The reservoirs have reasonably good porosity but generally low permeability due to elevated detrital clay content. A fair amount of cementation is seen similar as in the Balderbrå discovery well. However, cementation also has affected the cleanest and coarsest sandstone units resulting in the absence of better reservoir quality zones. A total amount of 35 XPT pressure points was attempted out of which only 5 were considered valid. The five valid points aligned with the regional, near-hydrostatic, water gradient seen in the Gullstjerne exploration well 6604/6-1. A water density of 0.968 g/cc was estimated. There were no oil shows above the oil-based mud in the well.

Two cores were cut. Core 1 was cut from 3770 to 3842 m in the Springar 2 sand with 101.35 % recovery. The core-log depth shift for this core is 6 m.