Offshore staff
LONDON -- EnCore Oil has found gas and oil in its Burgman exploration well 28/9-4 in the UK central North Sea.
Well 28/9-4, in block 28/9, reached TD 5,990 ft (1,826 m) MD, encountering good-quality hydrocarbons in a Tay sandstone interval. The partners have opted to proceed with a side track.
In more detail, the well encountered 22 ft (6.7 m) of net hydrocarbon pay within the overall Tay sandstone interval, comprising 12 ft (3.6 m) of gas in Upper Tay sandstones and 10 ft (3 m) of 24º API oil in Lower Tay sandstones. The Cromarty and Fulmar sections were not hydrocarbon-bearing at this location.
A gas/oil contact was calculated at 3,560 ft (1,085 m) TVD subsea and the oil/water contact at 3,980 ft TVDSS, giving a gross gas column of at least 78 ft (23.8 m) and a gross oil column of around 420 ft (128 m).
The location was selected to intersect all four potential reservoir horizons identified on seismic data. Although oil bearing, the Lower Tay sands are not well developed at this location. Seismic data, however, suggests that they are more thickly developed over a large part of the remaining prospect area, and lie above the oil/water contact.
The side track will target an area thought to contain more thickly developed Lower Tay sands.
Based on the results, the partners will reassess their surface drilling location for the nearby Carnaby prospect.
EnCore says all information from the wells drilled on block 28/9 will be integrated with a newly reprocessed 3D seismic data set to improve understanding of potential hydrocarbon volumes and hydrocarbon properties and to assist development planning for the licence.
Alan Booth, EnCore's CEO, said: "The presence of 24º API oil suggests that the oil quality in the license does not significantly degrade as we test increasingly shallower prospectivity, which is great news for a number of the undrilled prospects on the license. This short side track should, we believe, confirm thicker Lower Tay sands and help us further delineate what could be another important, good quality oil discovery in block 28/9.
"Following these results, EnCore is keen to return to the block to test the Carnaby, Rapide/West Varadero, and Bonneville prospects…The use of a semisubmersible rig would allow the Carnaby prospect to be drilled at a more appropriate location.”
03/21/2011
