An intriguing theory now permeating oil company research staffs suggests that crude oil may actually be a natural inorganic product, not a stepchild of unfathomable time and organic degradation. The theory suggests there may be huge, yet-to-be-discovered reserves of oil at depths that dwarf current world estimates.
The theory is simple: Crude oil forms as a natural inorganic process which occurs between the mantle and the crust, somewhere between 5 and 20 miles deep. The proposed mechanism is as follows:
Methane (CH4) is a common molecule found in quantity throughout our solar system - huge concentrations exist at great depth in the Earth.
At the mantle-crust interface, roughly 20,000 feet beneath the surface, rapidly rising streams of compressed methane-based gasses hit pockets of high temperature causing the condensation of heavier hydrocarbons. The product of this condensation is commonly known as crude oil.
Some compressed methane-based gasses migrate into pockets and reservoirs we extract as "natural gas."
In the geologically "cooler," more tectonically stable regions around the globe, the crude oil pools into reservoirs.
In the "hotter," more volcanic and tectonically active areas, the oil and natural gas continue to condense and eventually to oxidize, producing carbon dioxide and steam, which exits from active volcanoes.
Periodically, depending on variations of geology and Earth movement, oil seeps to the surface in quantity, creating the vast oil-sand deposits of Canada and Venezuela, or the continual seeps found beneath the Gulf of Mexico and Uzbekistan.
Periodically, depending on variations of geology, the vast, deep pools of oil break free and replenish existing known reserves of oil.