Some people think that petroleum has deep origin but abiogenic origin also.some people think it is biogenic in origin but fossil fuel only.but I think between the both that petroleum has deep origin only without any involvement of fossil but biogenic also because we can not ignore the strong chemical test evidence but there is no logic and cause that it is fossil fuel. so there is hard need to observe that why it has biogenic origin while it has deep origin also. there is no need to manipulate it with fossil fuel theory if it has biogenic origin.
according to me there are two type of sediments rocks.
1. sedimentary rocks that has been formed with organic matter from surface.
2. sedimentary rocks that has been formed with past seepage hydrocarbons and OM has been mixed in it when these liquid hydrocarbons has been floated on surface of earth by the past seepage .
according to me chances are high to get oil near type 2 sediments only and fossils has nothing to produce oil because we are getting nothing near type 1 sediments.
please observe the fine example of oil that is organic in origin but not fossil fuel. http://www.youtube.com/watch?v=CC7i5CY6XNo&NR=1 http://www.youtube.com/watch?v=a3lG3FX9D68