@mark noble,
whos the guy trying to sound intelligent on the youtube?? Hes dead wrong starting with his opening statement.
" some mens, like,Serpentinization will form a very small part of CH4. BUT, aabiogenesis means (Tropch process) are very unimportant to ven form "reserves".Serpentine occupies how much volume on the upper mantle (Limit stuff to where hydrocarbons would NOT simply oxidize or decompose.
Oil is primarily comprised of animal generated hydrocarbons from zooplankton and algae that rain down onto the ocean floor in deeper basins . It goes from fatty acids to kerogen to petroleum by diagenetic heating and compression.
Most commercial oil comes from species in just a few huge animal and algae phyla, eg the foraminiferans.