31/7-1 proved oil and gas and 31/7-1 A delineated the discovery.
The wells were drilled 13 km south of the Brage field in the North Sea.
The primary exploration target for the wells was to prove and delineate petroleum in Middle Jurassic reservoir rocks (the Fensfjord formation). The secondary exploration target was also in Middle Jurassic reservoir rocks (the Brent group) and the third exploration target was in the Lower Jurassic (the Cook formation and the Statfjord group).
Good reservoir quality
31/7-1 encountered a gas column of about 18 m and an oil column of about 21 m in sandstone in the Middle Jurassic Fensfjord formation. Reservoir quality is good.
Well 31/7-1 A, which delineated the discovery, encountered a gas column of 6 m and an oil column of 25 m at levels equivalent to those of the discovery well.
The secondary and third exploration targets were dry.
Preliminary estimates indicate that the size of the discovery is between 6.8 and 12.7 million m3 of recoverable oil equivalents.
The wells were not formation-tested, but extensive data acquisition and sampling have been carried out.
The licensees will assess tie-in of the discovery to existing infrastructure on the Brage field.
The wells are the first and second exploration wells in production licence 740, which was awarded in APA 2013.
Well 31/7-1 was drilled to a vertical depth of 2750 m below the sea surface, and was terminated in the Statfjord group in the Lower Jurassic. Well 31/7-1A was drilled to a vertical depth of 2270 m below the sea surface, and was terminated in the Fensfjord formation in the Middle Jurassic.
Plugging and abandonment
Water depth at the site is 140 m. The wells will now be permanently plugged and abandoned. The wells were drilled by the Transocean Arctic drilling facility, which will now drill wildcat well 36/7-4 in production licence 636 in the North Sea, where ENGIE E&P Norge AS is the operator.
Adapted from a press release by Louise Mulhall
Read the article online at: https://www.oilfieldtechnology.com/drilling-and-production/13072016/oil-and-gas-discovery-south-of-the-brage-field-in-the-north-sea/