Abiogenic theory

The abiogenic theory holds that hydrocarbons were a component of the material that formed the earth, through accretion of solids, some 4.5 billion years ago. With increasing internal heat, liquids and gases were liberated, and because they were less dense than the rocks, buoyancy forces drove them upward. In favorable conditions, the upward journey from the regions of origin would be dammed temporarily in porous rocks at depths that our drills can reach, and from which we then derive commercial petroleum.