OSLO, Norway – Marathon Oil Norge has discovered oil in the Earb South prospect in the Norwegian North Sea, its first well on license PL 505.
The semisub Transocean Winner drilled wildcat well 25/10-11 8 in 120 m (393 ft) water depth, 8 km (4.9 mi) southwest of the 25/7-2 discovery and 40 km (24.8 mi) south of the Heimdal field.
The main exploration target for the well was to prove petroleum in Upper Jurassic reservoir rocks (Draupne and Heather formation). A secondary target was reservoir rocks in the Middle Jurassic (Hugin formation).
According to partner Lundin Petroleum, the well encountered three separate hydrocarbon-bearing Jurassic sandstones sequences with poor reservoir quality. The uppermost oil-bearing interval comprised a 6-80-m (20-26-ft) thick sand sequence immediately below the Draupne shale.
Hydrocarbon samples also were taken from an underlying 285-m (935-ft) thick Upper Jurassic sequence, of which a 150-m (492-ft) thick interval was production tested. Oil and gas flowed to surface during this test, but sustained, stabilized flow was not achieved. Further hydrocarbons were encountered in a 20-30 m (65-98-ft) thick Middle/Upper Jurassic sequence.
Extensive data acquisition will form the basis for further evaluation of prospectivity in the area.
Ashley Heppenstall, president and CEO of Lundin Petroleum, said the discovery contained “significant in-place volumes. The well was tested and flowed oil and gas to surface but the reservoir is tight and further work will be required to determine whether the discovery can be commercialized.”
Transocean Winner now heads to PL 431 in the Norwegian Sea to drill wildcat well 6406/3-9 for Maersk Oil Norway.