Genesis 6: 14: Make thee an ark of gopher wood; rooms shalt thou make in the ark, and shalt pitch it within and without with pitch.
The Hebrew word for "pitch" in Genesis 6: 14 is “kopher”; kopher is asphalt or bitumen which are petroleum products sourced from oil.
The oil we have today was formed by the global upheaval of the Great Flood in Noah’s time which caused vegetation, animal, marine and human life to be compressed into the modern oil that is currently on tap.
The oil of Noah’s time however was formed from a much earlier age.
Genesis 1: 1 - 2: In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
God’s perfect and complete creation of Genesis 1: 1 was perverted by Satan (see The pre-Adamic civilization), and so God destroyed that creation in an act of judgment, causing the vegetation, animal and marine life to be compressed in the global upheaval that took place. This great compression formed the oil that fuelled the world of Noah’s time and from which the pitch was sourced to seal the ark.