Trondheim, 2010-05-12

Oil discovery in the Frøy area

Det norske oljeselskap ASA has discovered oil in Storklakken close to
the Frøy field. The proven volumes are between 7 and 12 million barrels
of oil equivalents. Det norske owns 100% of the licence.

Det norske, operator of production licence 460, has completed drilling
an exploration well (25/1-11) and a subsequent sidetrack (25/1-11 A) in
the Storklakken prospect. The wells were drilled using the Aker Barents
drilling rig.

The volumes proved through the two wells are estimated at between 7 and
12 million barrels (1.1 and 1.9 million Sm3).

The wells were primarily intended to prove hydrocarbons in the
Frigg/Odin formations (the Hordaland and Rogaland groups). Their
secondary purpose was to prove hydrocarbons in the Hermod/Heimdal
formations (the Rogaland Group).

Well 25/1-11 encountered oil in the upper part of a sandstone unit,
which has very good reservoir properties in the Frigg formation.
Sidetrack 25/1-11 A was drilled upflank towards the top of the
structure, and proved further oil reserves - also in very good reservoir
sands. The total oil column is roughly 19 metres in length. A
one-metre-long gas column was also proven. The discovery has not been
tested, but comprehensive data acquisition and sampling have been
carried out.

The wells proved good reservoir development in the Hermod/Heimdal
formations, but the sands did not contain any hydrocarbons.

Storklakken is located approximately 12 kilometres from the abandoned
Frigg field, five kilometres south of discovery 25/1-9, and 220
kilometres northwest of Stavanger.
The wells are the first exploration wells in production licence 460. The
licence was awarded as part of APA 2007.

Wells 25/1-11 and 25/1-11 A were drilled to a vertical depth of 2,298
and 2,225 metres below sea level, respectively, until they encountered
Palaeocene-age rock in the Heimdal formation.

The ocean depth is 107 metres. The wells will now be permanently plugged
and abandoned. The discovery is probably commercial, and tie-in with one
of the existing or planned installations in the area is being
considered.

Contacts:

Odd Ragnar Heum, Sr. VP Reserve and Area Development, tel.: +47 932 24
076
Knut Evensen, VP Investor Relations, tel.: +47 950 77 622

About Det norske:

Det norske oljeselskap ASA has interests in a total of 74 licenses, with
37 operatorships.

Det norske is the second-largest operating company on the Norwegian
Continental Shelf both considering number of operatotships and
exploration activity. I 2009 the company operated nine exploration
wells, and the high activity will continue in 2010. Det norske runs its
activities in a safe and responsible manner in close cooperation with
the authorities.

Det norske currently employs a staff of 180. The company`s registered
office is located in Trondheim. The company also has offices in
Oslo,Harstad, and Stavanger. Det norske is listed on the Oslo Stock
Exchange (DETNOR).