A Statoil well has established new-pool potential in old Gullfaks oil and gas field in the Tampen area of the North Sea offshore Norway.
Tests of the 34/10-A-8 production well on the Gullfaks A platform indicated what Statoil described as “considerable additional resources” in the Lower Paleocene Lista formation of the Upper Cretaceous-Paleocene Shetland Group.
Gullfaks, on stream since late 1986, has produced more than 2.4 billion bbl of crude oil and 56 billion cu m of natural gas, mainly from the Middle Jurassic Brent sandstone but also from Lower Jurassic and Upper Triassic sandstones of the Cook, Statfjord, and Lunde formations.
The company describes the Lista formation, slightly shallower than the Brent group, as claystone with turbidite sand and limestone stringers.
Lista potential has long been known, but the formation hasn’t been developed because of low reservoir quality, Statoil said. Since last December, however, the test well has produced nearly 1 million bbl of oil, currently at a stable rate of 7,500 b/d.
Interpretation, modeling, formation testing, and sampling of the pay interval indicate the discovery contains 40-150 million boe of oil and gas. Evaluation continues, Statoil said.
Gullfaks field, in 130-220 m of water, produced about 40,000 b/d of oil last year from three platforms.
Statoil, operator, holds a 70% interest. State-owned Petoro holds the remainder.