The drilling of appraisal well 35/9-10 on the oil discovery 35/9-7 Skarfjell (PL418) is nearing completion and successfully provided valuable reservoir information. The well was drilled in the North Sea approximately 40 kilometres north of the Troll Field and 2 kilometres southeast of the discovery well.
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 side-track 35/9-10A near the top of the structure in the south-western part. 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.
“This is an important area for us. 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” says Hugo Sandal, Managing Director of RWE Dea Norge. “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 continues.
Wellbore 35/9-10A, near the top of the structure to the southwest found a 59 meter 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 meters gross thick.
Wellbore 35/9-10S, on the southeast flank of the Skarfjell structure, proved a 13 meter gross gas column above an oil column of 49 meter 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 current assessment of recoverable resources from Skarfjell is between 10 and 23 million standard cubic meters oil and condensate and between 8 and 15 billion standard cubic meters of gas. The license owners in PL418 are currently evaluating possible development concepts.
The appraisal wells were terminated in the middle Jurassic, Rannoch Formation.