Statoil finds gas near Ekofisk field in North Sea
- Exploration & Production
Norwegian oil and gas major Statoil, operator of production licence 146, has found gas/condensate in the Julius prospect near the Ekofisk field in the North Sea, and is now in the process of concluding the drilling of wildcat well 2/4-23 S.
The Norwegian Petroleum Directorate (NPD) has said that the well was drilled about 17 kilometres northeast of the Ekofisk field, near the King Lear discovery in the southern part of the North Sea.
The NPD said that the primary exploration target for the well was to prove petroleum in Upper Jurassic reservoir rocks (the Ula formation) and Middle Jurassic reservoir rocks (the Bryne formation), as well as to delineate the King Lear discovery, which was proven in Upper Jurassic reservoir rocks (the Farsund formation) in the summer of 2012. Before well 2/4-23 S was drilled, the Statoil’s resource estimate for King Lear was between 11 and 32 million standard cubic metres of recoverable oil equivalents.
The secondary exploration target for 2/4-23 S was to prove petroleum in Upper Triassic reservoir rocks (the Skagerrak formation).
In the primary exploration target, the well encountered 41 metres of gas/condensate-filled sandstone rocks in the Ula formation, with moderate reservoir quality. The petroleum/water contact was not encountered. Preliminary estimates place the size of the discovery at between 2.5 and 12 million Sm3 of recoverable oil equivalents.
The well also encountered 30 gross metres of water-filled sandstone with poor reservoir quality in the Bryne formation.
In addition, the well encountered a 20-metre thick gas/condensate column in the Farsund formation, in two zones of five metre thick reservoir rocks with moderate/good reservoir quality, which confirmed pressure communication with the 2/4-21 King Lear discovery. Delineation of the 2/4-21 discovery will not lead to any change in the resource estimates, NPD says.
NPD further added that the Skagerrak formation had poor reservoir quality and was water-filled.
Also, the well was not formation-tested, but extensive data acquisition and sampling have been carried out.
The licensees will assess the discoveries together, with a view toward an optimal development.
This is the fourteenth exploration well in production licence 146, which was awarded in the 12th licensing round.
According to the NPD, well 2/4-23 S was drilled to a vertical depth of 5548 metres below the sea surface, and was terminated in sandstone in the Skagerrak formation in the Upper Triassic with water depth at the site being 68 metres. NPD notes that the well will now be permanently plugged and abandoned.
Well 2/4-23 S was drilled by the jack-up drilling rig Mærsk Gallant, which will now proceed to PL 018 to do well work on the Eldfisk field in the North Sea.
“The King Lear and Julius discoveries are located in one of the most mature parts of the Norwegian continental shelf – just 20 kilometres north of Ekofisk, the first commercial NCS discovery made 45 years ago. The discoveries confirm Statoil’s view that even such mature areas of the NCS still have an interesting exploration potential,” says May-Liss Hauknes, Statoil vice president for exploration in the North Sea.
“Since the King Lear discovery, the main focus of the licence partnership has been to clarify the resource basis within PL146/PL333. Following the positive results of the Julius well, the partnership will start working on an optimal plan for a timely development of the discovered resources. The Julius discovery will be included in the resource base for a future PL146/PL333 development decision,” says Edward Prestholm, acting head of early phase field development on the NCS in Statoil.