The company, in a stock market statement, said that the extension would allow it to complete the originally planned and permitted programme, including a full fourteen week flow testing programme. The extension moves the expiry to September 2018.
Additionally, UK regulator The Oil and Gas Authority has extended its approval to December.
UKOG said well testing operations are now underway.
The programme is specifically designed to gather supportive evidence that the Kimmeridge contains mobile light oil within an extensive continuous oil deposit that can flow to surface at commercial rates and in commercial volumes, UKOG added.