Partners in the Catcher discovery in the UK North Sea said yesterday new drilling results from the field had been a disappointment.
Premier Oil, which has a 35% stake in Catcher – the biggest share – said it now estimated overall reserves for the find at between 40million and 80million barrels of oil.
Even at the top end of that range, it is a substantial drop from the potential 300million barrels – including 120million recoverable – hoped for last June.
It was later speculated there could be as much as 300million barrels recoverable out of a gross resource of up to 800million barrels in the greater Catcher area.
Drilling results from the Catcher North well drilled to 5,265 feet revealed 34ft of net hydrocarbon pay, comprising 20ft of gas and 14ft of oil.
The oil figure reported was at the bottom end of pre-drilling expectations.
Net pay is the part of a reservoir holding oil that is economically viable to produce.
Premier said the well would now be plugged and abandoned, with attention turning to the Burgman prospect a few miles south-west.
Catcher – about 110 miles east of Aberdeen – has EnCore as operator and 15% stakeholder, with Germany’s Wintershall owning 20% and Agora Oil and Nautical Petroleum each having 15%.
Shares in Premier, EnCore and Nautical, which all have their head offices in London, took a battering on the stock market yesterday after the drilling result was announced.
Worst hit were EnCore and Nautical Petroleum, which both saw their share price slump by about 16%, to 128p and 455p respectively.
Premier, which has exploration and production operations in Asia, the Middle East, Pakistan and west Africa in addition to the North Sea, was down nearly 7% at £19.94.
Simon Lockett, Premier’s chief executive, said the gas result was in line with expectations but the oil net pay figure had been a disappointment.
He added: “The results of this well will now be integrated into the planned development for Catcher.
“We look forward to the results of the upcoming Burgman well and, thereafter, Carnaby.”
EnCore chief executive Alan Booth said: “Although somewhat disappointing, the results at Catcher North have confirmed our previously held view that Catcher, Catcher East and Catcher North are probably a single accumulation.”
Steve Jenkins, Nautical’s CEO, said: “We now have an improved understanding of the reservoir distribution.”