Some 1.2 billion barrels of oil have reportedly been discovered in the Horseshoe-1 and 1A wells in Alaska’s North Slope. If correct, it might be the biggest onshore discovery in the U.S. in three decades.
This North Slope find comes only some few months after Caelus Energy announced a potential supergiant Alaska oil discovery in the waters of Smith Bay (GEO ExPro No. 6, 2016).
Both discoveries, even if they are huge, may however be dwarfed if Statoil has success with the Korpfjell prospect in the Barents Sea later this year.
According to American terminology, a major oil field has 100MMbbls of oil or more in proven reserves. A giant field can recover more than 500MMbbls, while a supergiant has in excess of 5Bbbls of oil reserves.
In the best case scenario, the Korpfjell prospect has a potential for 10Bbbls of recoverable oil. That’s a lot of oil.
In comparison, the Statfjord Field – being the largest in the North Sea – has so far produced exactly 5Bbbls of oil equivalents, thereby qualifying to be a supergiant. Korpfjell has the potential to be twice as big.
Korpfjell belongs to a licence that was awarded in the Norwegian 23rd round and lies in the area named Barents Sea southeast.
This is very far north and only some few kilometres from the Russian border. It is definitely Arctic wildcatting.
The primary target is Jurassic sandstones with presumed excellent reservoir properties at very shallow depths (see illustration). Triassic sandstones with uncertain reservoir parameters constitute secondary targets.
De-risking of the prospect does of course include detailed geologic analyses based on well data, seismic data as well as 35 years of exploration experience. The geochemical and geophysical tool boxes have also been used extensively.
While 2D seismic outlines the structure, 3D seismic is necessary to understand the depositional systems and do AVO-analyses. Published accounts (GEO 05/2016) indicate anomalies that reflect gas overlying oil (double flat spot), and that the sedimentary sequence is “flush with gas”. There is every reason to believe we do have an active petroleum system in the area.
- However, unpublished accounts are a bit more pessimistic. CSEM-data acquired by EMGS indicate, as analysed by a Russian company, that the Jurassic sandstones do not contain hydrocarbons, while the same data points to possible hydrocarbons in the Triassic.
This will be discussed in the NCS Exploration conference in May in a talk given by Rosneft and EMGS: “Updated risk analysis of prospects in the Barents Sea South-East by implementation of CSEM data”.
See program here.
Drilling will start in the 2nd quarter this year.
