Shares in UK Oil & Gas (Ukog) soared in morning trading after the explorer said it observed further oil at its Bradford Bridge well in the Weald Basin.
"The presence of light mobile oil in fractured Kimmeridge shales is highly significant," the oil and gas explorer said. It observed mobile light oil seeping from multiple sections of fractured shales and limestones at the well, where it had started a coring drilling technique.
At first look, Ukog said this confirms the finding from its Horse Hill site that oil production was likely derived from a "much larger reservoir 'tank'".
Shares in the company, which is listed on London's Alternative Investment Market (Aim), rose 11.11 per cent to 2.25p.
"The coring programme continues to deliver positive results and important new insights into this continuous oil accumulation, the first of its kind discovered in the UK," said Stephen Sanderson, executive chairman at Ukog.
Ukog will now "rigorously examine" the possibility that it has encountered a single 600-700 feet thick, naturally fractured oil reservoir section encompassing all four Kimmeridge Limestones and underlying a significant proportion of the wider Weald Basin.
Sanderson said this testing is set to begin around the second half of July.