The well was drilled about 23 kilometres north of discovery well 7220/8-1 on the Johan Castberg field in the Barents Sea and 210 kilometres northwest of Hammerfest. 

Preliminary calculations indicate the size of the discovery is between 0.3 and 0.5 billion standard cubic metres (Sm3) of recoverable gas. This corresponds to 1.9 – 3.1 million barrels of oil equivalent. The licensees will assess the discovery with a view toward a possible tie-in to the Johan Castberg field.

This is the 15th exploration well in production licence 532, which was awarded in the 20th licensing round in 2009.

Well 7220/5-4 was drilled by the COSLProspector drilling rig.

Geological information

The objective of the well was to prove petroleum in reservoir rocks from the Middle Jurassic. The primary exploration target was the Stø Formation, and the secondary exploration target was the Nordmela Formation.

The well encountered a 14-metre gas column in the Stø Formation, in sandstone totalling 70 metres and with good reservoir quality. The gas/water contact was encountered 1849 metres below sea level. In the lower part of the Nordmela Formation, the well also encountered gas in a 3-metre thick isolated sandstone layer with moderate to good reservoir quality.

Above the primary exploration target, the well encountered a 14-metre thick sandstone layer from the Cretaceous, where a 1-2-metre thick zone in the lower part of the reservoir was filled with oil. The reservoir quality is poor to moderate.

The well was not formation-tested, but extensive volumes of data and samples were collected.

The well was drilled to a vertical depth of 2144 metres below sea level, and was terminated in the Fruholmen Formation from the Late Triassic.

Water depth at the site is 415 metres. The well will now be permanently plugged and abandoned.