The partners are ExxonMobil Exploration and Production Norway, Idemitsu Petroleum Norge and Neptune Energy Norge.
Preliminary estimates place the size of the new discovery between six to 16 million standard cubic metres (Sm³) of recoverable oil equivalent.
Equinor Norway UK Exploration senior vice-president said: “We are making one of this year’s biggest discoveries in the most mature area of the Norwegian continental shelf (NCS ), not far from the Troll field.
“This demonstrates the opportunities that still exist for value creation and revenue from this industry.”
The project licensees may plan to attach the discovery into existing infrastructure in the Troll-Fram area.
The exploration well 35/11-23, Echino South, has been drilled 3.2km south-west of Fram field.
Drilling aimed at primarily targeting petroleum in the upper Jurassic reservoir of the Oxfordian formation, while the secondary exploration target for the well was to prove petroleum in the Middle Jurassic Brent Group.
Equinor noted that there were proven hydrocarbons in both exploration targets.
Ashton added: “After more than 50 years of geological surveys on the NCS , we are still learning something new and finding hydrocarbons where we previously thought there were none.
“By utilising existing infrastructure, these resources may be recovered at good profitability and with low CO2 intensity.”
Vertical depth of the 35/11-23 well is 2,947m while its water depth is 350m. Well 35/11-23 was drilled using the Deepsea Atlantic drilling rig.
The well will be permanently abandoned after completing the sidetrack drilling of appraisal well 35/11-23 A, said Equinor .