“unconventional petroleum” means petroleum which does not flow readily to the wellbore. (6) In section 3 of the Petroleum Act 1998, at the end of subsection (4) add “and subsection (4A). “(4A) Nothing in this section permits the grant of a licence to search and bore for and get unconventional petroleum in Great Britain during the relevant period. (4B) For the purposes of subsection (4A) “relevant ...