Equinor and its partners reported an oil discovery with the Sputnik exploration well drilled in the Barents Sea. Recoverable resources are preliminarily estimated at 20-65 million bbl of oil.
Well 7324/6-1—the second exploration well in production license 855—was drilled using Seadrill’s West Hercules semisubmersible drilling rig 30 km northeast of the Wisting discovery (7324/8-1) to a vertical depth of 1,569 m subsea in 449 m of water. It was terminated in the Snadd formation in the Late Triassic.
The objective of the well was to prove oil in two reservoir levels in the middle part of the Snadd formation. The secondary objective was to test the reservoir properties in the lower part of the Snadd formation, as well as in a shallower reservoir level in the Sto formation from the Middle Jurassic. The exploration targets in the Snadd formation were in fluvial sandstones.
The well encountered a 60-m sandstone layer with poor reservoir quality in the upper part of the Snadd formation. The reservoir is water-bearing with traces of oil. The reservoir is at the same stratigraphic level where oil was proved in well 7325/4-1 (Gemini Nord).
In the middle part of the Snadd formation, the well encountered a 15-m oil column with poor reservoir quality. The oil-water contact was encountered in the well at a depth of 1,354 m. This reservoir is at a corresponding stratigraphic level as the 7324/3-1 (Intrepid Eagle) gas discovery.
In the lower part of the Snadd formation, the well encountered a 45-m water-bearing sandstone layer with poor reservoir quality. In the Sto formation, the well encountered 20 m of water-bearing sandstone with good reservoir quality.
More work is needed to determine commerciality, said Nick Ashton, senior vice-president for exploration in Norway and the UK, but “this discovery shows that persistence and our ability to learn from previous well results does pay off.”
In 2017, Equinor’s Gemini Nord well resulted in a very small, noncommercial oil discovery in a reservoir channel system within the PL855 license. In 2018, a larger channel complex was targeted in the neighboring PL615 license, with the Intrepid Eagle well. This well proved a 200 m gas column, but no oil. The Sputnik well, the second well in PL855, has proved oil in a large channel system.
“Detailed fluid analysis combined with geological and geophysical mapping will be carried out to fully understand the commercial potential of the Sputnik discovery. If confirmed that the structure comprises volumes that can be recovered in a commercially viable way, the partnership will assess possible development solutions,” Ashton said.
The West Hercules rig has moved on to drill the Equinor-operated Lanterna well in PL796 in the Norwegian Sea.
Equinor is operator and holds 55% of PL 855. Partners are OMV 25% and Petoro 20%.