The company revealed that the PBU results were significantly better than expected, showing little or no apparent pressure depletion compared to prior PBU testing back in April.
Production volumes from the Portland reservoir now exceeds 20,500 barrels of oil, and, the most recent production rate measured 220 barrels of oil per day - with the rate purposely constrained to protect future field performance.
Previously in testing the Portland saw a peak production rate of 362 bopd.
Overall, the full extended well test has produced more than 45,500 barrels of oil. The programme aims to produce a total of 50,000 barrels. Once 25,000 barrels have been produced from the Portland reservoir, testing will revert back to the Kimmeridge zone.
"The Portland test programme continues to exceed our technical expectations with dry oil production now exceeding 20,500 barrels,” said Stephen Sanderson, UKOG chief executive.
“Our overall testing costs have also been significantly offset by the associated sales revenues.”
“The recent extensive pressure build-up also indicates HH-1 is likely connected to a larger oil volume than previously recognised. Further Portland test data will now be collected and analysed before the HH-2 drilling campaign to confirm this important development.”
In the coming months attentions will turn to the drilling of a new horizontal well which is expected to yield two or three times higher production rates that the Portland’s peak rate in the vertical well.
The Horse Hill partners are now finalising contracts for the upcoming drill programme.