Equinor Energy AS has discovered gas and condensate in Lofn and Langemann wells in the Sleipner area of the North Sea.
In a release Dec. 5, Equinor said preliminary estimates indicate that the reservoirs may contain 5-18 million std cu m of recoverable oil equivalents (30-110 MMboe), the operator's largest discoveries so far this year, and that the find could be developed for the European market through existing infrastructure.
Drilling details
Wells 15/5-8 S (Lofn) and 15/5-8 A (Langemann) are the first and second exploration wells to be drilled in production license (PL) 1140, 40 km northwest of Sleipner A between Gudrun and Eirin fields 240 km west of Stavanger.
The wells were drilled by the Deepsea Atlantic rig in 107 m of water. Exploration targets for both wells were to prove petroleum in two separate prospects in Middle Jurassic reservoir rocks in the Hugin formation and Triassic reservoir rocks in the Skagerrak formation, according to a separate release from the Norwegian Offshore Directorate (NOD).
Lofn was drilled to 4,636 m MD and 4,319 m TVD subsea, and Langemann was drilled to 4,932 m MD and 4,357 m TVD subsea. Both landed in the Skagerrak formation and both are classified as high-pressure, high temperature (HPHT) wells.
Lofn encountered gas-condensate-bearing sandstone layers in the Hugin formation with a thickness of 116 m, 36 m of which were sandstone layers with moderate to very good reservoir quality. The gas-water contact was not encountered.
The well encountered a 173-m thick reservoir interval in the Skagerrak formation, 59 m of which were sandstone layers with moderate to very poor reservoir quality. The reservoir was aquiferous.
Langemann encountered gas-condensate-bearing sandstone layers in the Hugin formation with a thickness of 125 m, 31 m of which were sandstone layers with moderate to good reservoir quality. A possible gas-water contact was interpreted between 4,141–4,148 m subsea.
The well encountered a 95-m thick reservoir interval in the Skagerrak formation, 17 m of which were sandstone layers with very poor reservoir quality. The reservoir was aquiferous.
Lofn’s preliminary estimated size is 3.5–10 million std cu m of recoverable oil equivalent (22–63 MMboe). Langemann’s preliminary estimated size is 1–8 million std cu m of recoverable oil equivalent (6–50 MMboe).
The wells were not formation-tested, but extensive volumes of data and samples were collected. The wells have been permanently plugged.
Sleipner area potential
Kjetil Hove, executive vice-president for exploration and production Norway, Equinor, said the find demonstratees the importance of maintaining exploration activity on the Norwegian continental shelf.
“The Sleipner area is an important hub for Norwegian gas exports to Europe. These discoveries strengthen our optimism for further exploration in the area," he said, noting the operator and its partners are "committed to drill five additional exploration wells going forward."
The rig will now continue to the Sleipner-area Sissel prospect for Equinor and partner ORLEN Upstream Norway, near Utgard field.
Equinor is operator at PL 1140 (60%). Aker BP ASA holds the remaining 40%.
