Wintershall Norge AS to complete drilling of North Sea wells

Wintershall Norge AS, operator of production licence 418, is about to complete drilling of appraisal wells 35/9-10 S and A on the 35/9-7 oil discovery (Skarfjell).

The appraisal wells are being drilled in the North Sea, around 40 km north of the Troll field and 2 km southeast of the discovery well.

The discovery was proven in the spring of 2012 in two Late Jurassic sandstone layers in the Heather formation. Appraisal well 35/9-10 S was drilled in the southeastern part of the "Skarfjell structure" and sidetrack 35/9-10 A near the top of the structure in the southwestern part. Before well 35/9-10 S was drilled, the resource estimate for the discovery was between 10 and 25 million m³ of recoverable oil.

Define the extent of the discovery
The objective of the two wells was to examine thickness, properties, fluid content and depth to the Upper Jurassic reservoir to define the extent of the discovery to the south, and clarify whether the discovery has a gas cap.

Well 35/9-10 S encountered a 13 m (gross) gas column and an oil column of 49 m (gross) in three thin sandstones in the upper “Intra Heather” 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 the discovery.

Well 35/9-10 A encountered a 59 m (gross) gas column in the upper "Intra Heather" sandstone with better than expected reservoir quality. Pressure data indicates that the proven gas cap is in communication with the oil zone proven in 35/9-7 and in appraisal well 35/9-8 in the northern part of the discovery. The lower "Intra Heather" sandstone is only 4 m thick, contains oil and has poorer reservoir quality than expected.

Preliminary calculations place the size of the discovery between 10 and 23 million m³ of recoverable oil and condensate, and between 8 and 15 billion m³ of recoverable gas.

The wells were not formation-tested, but extensive data acquisition and sampling have been carried out.

Future development
The licensees will assess the discovery together with other nearby discoveries for possible development solutions.

This is the third exploration well in production licence 418. The licence was awarded in APA 2006.

Appraisal well 35/9-10 S was drilled to a vertical and measured depth of 2837 m and 3595 m below the sea surface, respectively. Appraisal well 35/9-10 A was drilled to a vertical and measured depth of 2835 m and 3179 m below the sea surface, respectively. Both wells were terminated in the Rannoch formation in the Middle Jurassic.

Water depth is 365 m. The wells will be plugged and abandoned.

The wells were drilled by Transocean Arctic, which will proceed to production licence 586 in the Norwegian Sea to drill wildcat well 6406/12-3 S where VNG Norge AS is the operator.

Adapted from press release by Cecilia Rehn

Read the article online at: https://www.oilfieldtechnology.com/exploration/21012014/wintershall_norge_as_is_about_to_complete_drilling_of_appraisal_oil_wells_in_the_north_sea/