25/2-10 S (Frigg-GammaDelta) is a discovery in the central North Sea, 20 kilometres east of the Frigg field. The water depth is 120 metres. The discovery was proven in 1986 on the Frigg Gamma structure. The reservoir contains oil and gas in sandstone of Eocene age in the Frigg Formation, at a depth of 1,900 metres. The resources also include the Frigg Delta structure, where well 25/2-17 drilled in 2009 proved oil at the same reservoir level. The plan is to develop Frigg-GammaDelta as part of the Yggdrasil development (formerly NOAKA), together with other discoveries and abandoned fields in the area between the Oseberg and Alvheim fields. In December 2022, three plans for development and operation (PDO) were submitted for the Yggdrasil development, including the projects Hugin, Fulla and Munin. The PDO for Hugin includes a process platform with living quarters, Hugin A, located at Frigg-GammaDelta in the southern part of the Yggdrasil area.