A group led by Premier Oil PLC has encountered oil at the Carnaby exploratory well on Block 28/09-5A in the UK Central North Sea.
The well went to a total depth of 4,695 ft and cut 51 ft of net oil in the main Tay sandstone in an estimated 86-ft oil column. A core confirmed oil in excellent quality sandstones, Premier said.
Pressure data and sampling indicates that the oil is 24° gravity and of similar quality to that established at the nearby discoveries at Catcher, Varadero, and Burgman.
“The oil-water contact was at the shallower end of expectation, driven by the more complex geology associated with this type of footwall prospect. The well also encountered 51 ft of Cromarty sands, but these were shown to be water wet on the logs.”
Nautical Petroleum PLC, which has a 15% interest in Carnaby, said preliminary log analysis indicates that the average porosity in the reservoir interval is 36% and the average oil saturation is 85%. The well also intersected thin hydrocarbon-bearing sands in the Tay above the main oil reservoir and water-bearing Tay sands 100 ft below the oil zone.
Premier said the high-quality data acquisition from the well will now be used to determine what contribution the Carnaby discovery will make to the overall Catcher development. The well will be plugged and abandoned ahead of the rig moving to drill the high-risk Coaster prospect on Block 28/10a, immediately east of the Catcher acreage.
Premier Oil operates Carnaby with 50% interest. A Wintershall AG unit has 20% interest, and Cairn Energy PLC has 15% through its fully-owned subsidiary Agora Oil & Gas AS.