Det norske oljeselskap AS drilled appraisal wells 16/1-21 S and 16/1-21 A on the Ivar Aasen Field in the Norwegian North Sea, the Norwegian Petroleum Directorate said April 22. The company operates production license 001 B there, the directorate added.

Ivar Aasen is in the central part of the North Sea and is comprised of production licenses 001 B, 028 B, 242, 338 BS and 457. The plan for development and operation was submitted to the Ministry of Petroleum and Energy on Dec. 21, 2012, the directorate added.

Before the appraisal wells were drilled, Ivar Aasen had 24 MMcm of recoverable oil, 1 MM cm of recoverable condensate and 4.5 B cm of recoverable gas. Wells 16/1-21 S and 16/1-21 A are targeting Middle Jurassic and upper Triassic reservoir rocks and reservoir quality in the Hugin, Sleipner and Skagerrak formations, and in the Statfjord group. They will measure the overlying gas cap in the eastern part of the field. Well 16/1-21 S had a secondary exploration target in overlying Paleocene reservoir rocks in the Heimdal Formation.

In the Skagerrak, well 16/1-21 S hit a 54-m undersaturated oil column. There were 25 m of good reservoir quality. There is also undersaturated oil in the eastern part of the field. Gas was not encountered. In the Heimdal, the well hit 27 m of good quality aquiferous sandstone.

Well 16/1-21 A found a 41-m oil column and a 4-m gas column. There was good reservoir quality in the Sleipner and Skagerrak. Oil in Sleipner was saturated.

Additional work will integrate new data, the directorate said.

These are the fourth and fifth appraisal wells in production license 001 B. This production license was carved out of production license 001 on Dec. 15, 1999. That license was originally awarded on Sept. 1, 1965 in the first licensing round.

Wells 16/1-21 S and 16/1-21 A were drilled to 2,630 m and 3,313 m, respectively. Both were terminated in the Upper Triassic Skagerrak. The wells have been permanently plugged and abandoned. Water depth at the site is 113 m.

The Maersk Interceptor drilled the wells and will continue drilling appraisal well 16/1-22 S in the western part of Ivar Aasen Field.