The company has now completed a series of comprehensive post-well studies on the Barryroe 48/24-10z well, which had been drilled and tested in March.
The assessment incorporated data from all six wells drilled on the Barryroe discovery in SEL 1-11, together with recently acquired and processed 3D seismic data, existing 2D seismic data, and other regional data.
Providence stated that the analysis demonstrated that the Barryroe trap at Base Wealden level was situated in the hanging-wall side of an inverted major intra-basinal growth-fault system and covered an area of several hundred square kilometres.
It said the crest of the structure was located at a total depth of about 6400 feet, with hydrocarbons logged as deep as about 7300 feet, with no evidence of an oil-water contact.
Reservoir fluid data from the well had indicated that it was unlikely for there to be any primary gas cap present at the crest of the structure in the Basal Wealden sands, Providence stated.
“The subsurface mapping and geological modelling results have confirmed that the Barryroe structure covers a very large area, and comprises four distinct hydrocarbon-bearing reservoir zones,” Providence chief executive Tony O’Reilly said in a statement.
“The lack of any logged water-bearing reservoir intervals in the lower circa 1500 feet of our recent 48/24-10z attests to the resource potential within the Barryroe structure, and strongly suggests that there may also be material hydrocarbon potential at deeper reservoir intervals within the structure,” he added.
The company reported that a mid-case Basal Wealden average net sand thickness of 23 feet had been assumed across the structure for volumetric purposes and, when combined with well petrophysical parameter, resulted in an in-place proven and probable resource estimate of 756 million barrels of oil and a proven, probable plus possible resource of 906 million barrels.
The resource figures for the Middle Wealden level were not revised.
The assessment also identified further upside potential in the hydrocarbon-bearing Lower Wealden and Purbeckian sands, as well as deeper exploration potential at the Upper Jurassic level, which was currently undrilled.
The company said it had started mapping of these newly prospective zones and planned to provide an additional resource update once this work was completed.
“It is clear from these studies that Barryroe is a substantial oil accumulation across multiple stacked horizons with much running room for further resource growth,” O’Reilly said.
Lying 50 kilometres off the south coast of Ireland in SEL 1-11, Barryroe is 80% owned and operated by Providence, with Lansdowne Oil and Gas holding a 20% stake.