why is crude oil extracted from the earth called petroleum Share with your friends Share 0 Toshaan answered this Because here at earth decomposition of plants and animal results in production of petroleum and there is no plant or animal so that decomposition process could occur 1 View Full Answer Aashirbad Sabat answered this BCOZ OF DECOMPOSITION OF DEAD ORGANISMS BCOZ OFDECOMPOSITION OF D BCOZ OFDECOMPOSITION OF D BCOZ OFDECOMPOSITION OF D BCOZ OFDECOMPOSITION OF D -4 Khushi Agrahari answered this Because petroleum is found trapped between two layers of rocks .Its name is derived from latin words....Petra(meaning: rock) and Oleum (meaning:oil).. 5 Yash Sharma answered this Because it is always found trapped between two rock caps.And the word Petra (means rock) and oleum(means oil) 0