Equinor makes gas discovery in Barents Sea

Exploration & Production

Norwegian oil and gas company Equinor has made a gas discovery northwest of Atlantis gas discovery located in the Barents Sea offshore Norway.

The West Hercules drilling rig in the Barents Sea. (Source: Equinor. Photo: Ole Jørgen Bratland)
The West Hercules drilling rig in the Barents Sea. (Source: Equinor. Photo: Ole Jørgen Bratland)

According to a Thursday report by the Norwegian Petroleum Directorate (NPD), Equinor has completed the drilling of wildcat well 7324/3-1, in its operated production license 615.

Equinor received consent from the Petroleum Safety Authority (PSA) to drill the 7324/3-1 well and investigate a prospect named Intrepid Eagle using the West Hercules drilling rig last June. The company was granted a drilling permit for the well by the NPD in September.

The well was drilled about 15 kilometers northwest of discovery well 7325/1-1 (Atlantis) and 370 kilometers north of Hammerfest.

The well’s primary exploration target was to prove oil in reservoir rocks from the Late Triassic Age (upper part of the Snadd formation).

The secondary exploration target was to prove petroleum in reservoir rocks from the Middle Jurassic Age (Stø formation) and in a deeper exploration target from the Middle Triassic Age (lower part of the Snadd formation). The secondary exploration target in the Snadd formation was the same stratigraphic level as gas discovery 7325/1-1 (Atlantis), and well 7324/3-1 was also intended to delimit this discovery. Before well 7324/3-1 was drilled, the resource estimate for discovery 7325/1-1 (Atlantis) was between 0.5 and 2 billion Sm3 of recoverable gas.

The NPD said that, in the primary exploration target, a total gas column of about 30 meters was encountered in the upper part of the Snadd formation, of which 20 meters was in an effective reservoir of primarily moderate to poor reservoir quality. The gas/water contact was encountered at 1492 meters below the sea surface.

In the secondary exploration target in the lower part of the Snadd formation, gas was also encountered in sandstone of poor to moderate reservoir quality. The gas column has not been clarified, as efforts to define a gas gradient were unsuccessful due to the tight formation.

In the other secondary exploration target, 15 m of aquiferous reservoir sandstone was encountered in the Stø formation, with moderate to good reservoir quality.

Preliminary calculations of the size of the discovery in the upper part of the Snadd formation are between 10 and 20 billion standard cubic meters (Sm3) of recoverable gas. In the lower part of the Snadd formation, the gas volume is estimated at between 1 and 4 billion standard cubic meters (Sm3) of recoverable gas. The discovery’s profitability is currently unclear.

The well was not formation-tested, but extensive data acquisition and sampling were carried out.

This is the third exploration well in production license 615, which was awarded in the 22nd licensing round in 2011.

The well was drilled to a vertical depth of 1678 meters below the sea surface, and was terminated in the Snadd formation from the Late Triassic Age. Water depth at the site is 452 meters. The well will now be permanently plugged and abandoned.

The well 7324/3-1 was drilled by the West Hercules semi-submersible drilling rig, which will now drill appraisal well 7122/7-7 S on the Goliat field in the Barents Sea in production license 229, where Eni Norge is the operator.