Wintershall Norge AS and its partners are nearing completion on the 35/9-10 appraisal well to assess the 35/9-7 Skarfjell (PL418) oil discovery. The appraisal well is in the North Sea 40 km north of the Troll field and 2 km southeast of the discovery well.
The current assessment of recoverable resources from Skarfjell is 10-23 million cu m of oil and condensate, and 8-15 billion cu m of natural gas. The license owners in PL418 are currently evaluating possible development concepts.
Appraisal well 35/9-10 was drilled in the southern part of the Skarfjell structure with the wellbore 35/9-10S on the southeast flank and the sidetrack 35/9-10A near the top of the structure in the southwestern part.
The partners said the purpose of the two wellbores was to investigate the thickness, properties, fluid content, and depth of the upper Jurassic reservoir to further define the Skarfjell discovery extension towards the south.
Wellbore 35/9-10A, near the top of the structure to the southwest, found a 59 m gross gas column in the upper Intra Heather sandstone with better reservoir properties than expected.
Pressure data indicates that the gas cap is in communication with the oil proven in the 35/9-7 and 8 wells in the northern part of Skarfjell. The lower Intra Heather sandstone was 4 m gross thick.
Wellbore 35/9-10S, on the southeast flank of the Skarfjell structure, proved a 13-m gross gas column above an oil column of 49 m gross in three thin sandstones in the upper Intra Heather reservoir with reservoir quality as expected.
Pressure data shows that this area has a lower reservoir pressure and is not in direct communication with the western and northern part of Skarfjell.
The appraisal wells were terminated in the middle Jurassic, Rannoch formation.
“This is an important area for us,” said Hugo Sandal, partner RWE Dea Norge managing director, “We are participating in several surrounding licenses. One being PL420 where we made the Titan discovery in 2010, and where we will drill an appraisal well in February this year.”
Preliminary estimates in 2010 of the Titan discovery size were 2-10 million cu m of oil equivalent, which was mostly oil (OGJ Online, Dec. 8, 2010).
“We have a good geological understanding of this area, and we will be well positioned to take on even more responsibility in this part of the North Sea in the years to come,” Sandal said.
Wintershall is operator in the license with 35% interest. Partners include Bayerngas Norge 20%, Capricorn Norge 20%, Edison International Norway Branch 15%, and RWE Dea Norge 10%.