Equinor discovers oil, gas at Granat prospect in North Sea

Equinor Energy AS and its partners have discovered oil and gas in the Granat prospect in the North Sea near Gullfaks, 190 km northwest of Bergen, the Norwegian Offshore Directorate reported Feb. 16.  

Preliminary estimates place the discovery at 0.2-0.6 million std cu m of recoverable oil equivalent (1.3-3.8 million bbl).

The licensees are considering tying the discovery back to existing infrastructure in the Gullfaks area.

Wildcat wells 33/12-N-3 HH and 33/12-N-3 GH were drilled in connection with drilling an oil development well on the Gullfaks Satellites (33/12-N-3 IH) in production license 152 (PL 152).

The discovery was made in 33/12-N-3 HH in production license 277. This is the first exploration well in the license. Well 33/12-N-3 GH, which had drilling targets in PL 152, was dry.

The wells were drilled from production licence 050 using the Askeladden rig.

Geological information

The objective of wellbore 33/12-3GH (N2A) was to prove hydrocarbons in reservoir rocks in the Tarbert Formation, with secondary targets in the Ness and Etive formations, all in the Brent Group from the Middle Jurassic.

The well encountered the Tarbert Formation in a total of 115 m with 48 m of sandstone layers with moderate to good reservoir properties and a total of 59 m in the Ness formation with 10 m of sandstone layers with good reservoir properties. Both formations were aquiferous. Data was collected, including pressure data.

Wellbore 33/12-3-GH was drilled to respective measured and vertical depths of 6,708 and 3,460 m and was terminated in the Ness formation.

The objective of wellbore 33/12-N-3 HH was to prove hydrocarbons in reservoir rocks in the Tarbert formation, with secondary targets in the Ness and Etive formations, all in the Brent Group from the Middle Jurassic.

Wellbore 33/12-N-3 HHT2 encountered a total of 153 m in the Tarbert formation with 58 m of sandstone layers with moderate reservoir quality. The wellbore encountered a total of 162 m in the Ness formation with 47 m of sandstone layers with moderate to good reservoir properties, and a total of 26 m of sandstone layers in the Etive formation with poor to moderate reservoir properties. The Tarbert formation contained gas, while the Ness and Etive formations were filled with oil/condensate. The well encountered a hydrocarbon column totaling 240 m. The oil-water contact was not encountered. Data was collected, including pressure data.

Wellbore 33/12-N-3 HH was plugged after being drilled to a vertical depth of 3,275 m due to an unstable hole. Technical sidetrack 33/12-3 HHT2 was drilled to respective measured and vertical depths of 7,846 and 3,715 m and was terminated in the Drake formation. 

Water depth at the site is 137 m, and the wells have been permanently plugged and abandoned.

Equinor is operator of the license with 51% interest. Parters are Petoro AS (30%) and OMV (Norge) AS (19%).