Someone just told me that the earth can create oil all on its own. Surely this is not true?

Question

Not including the process that creates fossil fuels.

Answer 1

Most geologists view crude oil, like coal and natural gas, as the product of compression and heating of ancient organic materials over geological time scales. According to this theory, it is formed from the decayed remains of prehistoric small marine animals and algae. (Terrestrial plants tend to form coal.) Over millennia this organic matter, mixed with mud, is buried under thick sedimentary layers of material. The resulting high levels of heat and pressure cause the remains to metamorphose, first into a waxy material known as kerogen, and then into liquid and gaseous hydrocarbons in a process known as catagenesis. Because hydrocarbons are less dense than the surrounding rock, these migrate upward through adjacent rock layers until they become trapped beneath impermeable rocks, within porous rocks called reservoirs. Concentration of hydrocarbons in a trap forms an oil field, from which the liquid can be extracted by drilling and pumping.

Geologists also refer to the "oil window". This is the temperature range that oil forms in--below the minimum temperature oil does not form, and above the maximum temperature natural gas forms instead. Though this corresponds to different depths for different locations around the world, a 'typical' depth for the oil window might be 4 - 6 km. Note that oil may be trapped at much shallower depths, even if it is not formed there. Three conditions must be present for oil reservoirs to form: a rich source rock, a migration conduit, and a trap (seal) that concentrates the hydrocarbons.

The reactions that produce oil and natural gas are often modeled as first order breakdown reactions, where kerogen breaks down to oil and natural gas by a large set of parallel reactions, and oil eventually breaks down to natural gas by another set of reactions.

Answer 2

The person you've been talking to probably refering to a theory `where oils generated from earth mantle activities'. The theory and study is available online, I have read it sometime ago. It was developed by some mathmatician or physicist not a geologist. But so far from study of oil samples ever produced or dicovered, always points to organic origins (kerogen). It either marine algae, lacustrine algae, terrestarial (plant) sources or mixed kerogen. The type of kerogen will generate variations in oil type some are slight waxy and some high in soluble gas others can be very waxy it looks like wax or candle in room temperature. Plant origins are prone to generate gas.

Answer 3

You heard about abiotic oil, the theory that oil forms without compression and heating of biologic material, but formed in the formation of the earth. This is a popular theory among Russian geologists, but in the US it is not accepted.

Basically, there is some geochemical evidence of non-organic oil, but if it is there it is most likely a small percentage. Think of it this way, big oil puts bilions upon billions into the scientific study of oil, making the formation of oil the best studied scientific subject on the planet. They say know, I tend to believe them. It's in their interest to get it right.

Answer 4

I dont think so,oil comes from fossil fuels,it does not form spontaneosly,or else why to worry about oil resrves.

Answer 5

I really don't believe that at all, but I'll look into it though.