6507/2-5 S

General

Well 6507/2-5 S (Ørn) is located on the Dønna Terrace in the Norwegian Sea, approximately 10 km southwest of the Marulk field. The objectives were to prove presence of hydrocarbons in the Fangst Group, Middle Jurassic shallow marine deposits in the Ørn structure, and acquire sufficient information on reservoir and fluid properties to be able to decide on a potential appraisal well for middle Jurassic discovery. If hydrocarbons are proven in Garn or Ile formations, the well would drill into Tofte and Tilje formations to clarify if these are water bearing. In addition, acquire data on reservoir and fluid properties in the Lysing Formation interval for regional understanding with the aim to clarify the relationship between logged resistivity, calculated saturation, and water salinity.

Operations and results

The well was entered with the semi-submersible rig West Phoenix on 23 July 2019 and drilled to TD at 4230 m (4186 m TVD) in the Early Jurassic Tilje Formation. The well was drilled down to 1386 m with seawater and CMC spud sweeps, from 1386 to 2807 with Versatec oil-based mud and from 2807 to TD with Exploradrill oil-based mud. The well was drilled vertical until 2000 m where it started to build inclination in the 17 ½’’ and 12 ¼’’ hole sections, before returning to vertical before 12 ¼’’ hole section TD.

The Lange Formation was penetrated at 2981 m (2918.4 m TVD MSL) and consists of predominantly claystone with single meter-scale limestone stringers as well as occurrences of sandstone bodies in the lower half. Unexpected hydrocarbon indications were observed in multiple levels within the Lange Formation. However,