7219/8-2

General

Well 7219/8-2 was drilled on the Iskrystall prospect in the Bjørnøyrenna Fault Complex southeast of the Johan Castberg Field in the Barents Sea. The primary objective was to prove hydrocarbons in the Stø, Nordmela and Tubåen formations and to prove the hydrocarbon-water contact observed in the seismic data.

Operations and results

Wildcat well 7219/8-2 was spudded with the semi-submersible installation West Hercules on 16 July 2013 and drilled to TD at 3425 m (3413 m TVD) in the Late Triassic Fruholmen Formation. No shallow gas was observed neither in the pilot hole nor main hole. From new data received while drilling it seemed possible to drill into a faulted zone in top of the reservoir. This lead to a decision of deviating the well through the Kolmule formation, so that the reservoir would be encountered outside the faulted zone. The well path was then built to 6.85 degrees through the Kolmule Formation. The well was drilled with seawater and hi-vis sweeps down to 1167 m, with KCl/Polymer/Glycol mud from 1167 m to 2681 m, and with Low Sulphate/KCl/Polymer/Glycol mud from 2681 m to TD down to TD.

In the overburden, the well penetrated Tertiary and Cretaceous claystones and limestone stringers as well as Jurassic claystones. In the reservoir, the well penetrated sandstone, siltstone and claystones of Jurassic and Late Triassic age. The target reservoir, top Stø Formation, was penetrated at 2898 m. A 132 m gas column was proven in the Stø and Nordmela formations. No oil zone was encountered. The gas-water contact (GWC) was not seen in the well, but there was a gas down-to (GDT) in the lower shaly part of Nordmela Formation at 3106 m (3098 m TVD). Based on the gas and water gradi