A couple of factually misleading points here, for reference:
(1) The Greek for "rock" is "petra", not "petros". ("Petros" comes from when Jesus made a pun on the word in giving Simon Peter his new name -- "petra"/"rock" is feminine; "petros", the form Jesus invented, is masculine.)
(2) There's no certainty that Greek fire contained petroleum. There are several other possibilities, and no particular reason to prefer the petroleum hypothesis.
(1) The Greek for "rock" is "petra", not "petros". ("Petros" comes from when Jesus made a pun on the word in giving Simon Peter his new name -- "petra"/"rock" is feminine; "petros", the form Jesus invented, is masculine.)
(2) There's no certainty that Greek fire contained petroleum. There are several other possibilities, and no particular reason to prefer the petroleum hypothesis.