According to biogenic fossil fuel theory, oil can only be found in sedimentary rock and not below the mythological 15,000 foot "Oil Window." See so-called "Dr." Kenneth Deffeyes's Hubbert's Peak.
The next chapter of this book explains that there is an "oil window" that depends on subsurface temperatures. The rule of thumb says that temperatures 7,500 feet down are hot enough to "crack" organic-rich sediments into oil molecules. However, beyond 15,000 feet the rocks are so hot that the oil molecules are further cracked into natural gas. The range from 7,000 to 15,000 feet is called the "oil window." If you drill deeper than 15,000 feet, you can find natural gas but little oil.Richard Heinberg's The Abiotic Oil "Controversy"
the temperatures at depths below about 15,000 feet are high enough (above 275 degrees F) to break hydrocarbon bonds. What remains after these molecular bonds are severed is methane, whose molecule contains only a single carbon atom. For petroleum geologists this is not just a matter of theory, but of repeated and sometimes costly experience: they speak of an oil “window” that exists from roughly 7,500 feet to 15,000 feet, within which temperatures are appropriate for oil formation; look far outside the window, and you will most likely come up with a dry hole or, at best, natural gas only.here
Oil starts out as organic material, any kind of organic material, from algae to dead fish to organic material found in fish fecal pellets. This material must sink to an oxygen-free bottom where the absence of oxygen allows it to decay. Then it must be covered with other sediment and pushed into the "oil window" which starts at a depth of 7,500 feet deep and ends at 15,000 feet in depth. Above 7,500 feet, the temperature is not hot enough to "crack" the organic material into oil molecules and below 15,000 feet, everything is cracked all the way into natural gas. Inside that window, the temperature is at "coffee pot" levels and after a few million years, the organic material is cracked into oil.here
Much of the book explains how heat "cracks" the complicated organic residues of dead plants to create oil. In general, the material must have, at some point, been trapped between 7,000 and 15,000 feet below the earth's surface. This is called the "oil window." Closer to the surface, temperatures are too low to make oil; deeper down, it is so hot that the material gets turned into natural gas.The Oil Window.
The oil window refers to the depth at which the process of turning kerogen into oil can occur – from 6,000-7,000 ft. to 13,000-15,000 ft. At this point our "source rock" (the original rock) will be "cracked" into oil. ("Cracking," apparently, is the term of choice used by petroleum geologists.) At greater depths you would not get oil from the cracking, but gas.And the Wikipedia entry for Petroleum
Geologists often refer to an "oil window"They all say "geologists" plural but so far Deffeyes is the only so-called "geologist" I've found who has made such a claim (in other words the whole world is learning from this moron).
The reality is that oil rigs have been drilling below 15,000 feet true vertical depth looking for oil since 1938. And guess what else? They've found it!!!
InfoGulf.Com via Offshore Mag: Exploration and Development Below 15,000 feet TVD.
For exploration greater than 15,000 ft TVD on the shelf during the period 2003-2005, 115 wellbores (45 in 2003, 41 in 2004, and 29 in 2005) were drilled by 35 operators.Those wells were drilled at least 3 years ago. We are finding oil much deeper now. According to Chris at Anadarko, the Grand Cayman well was drilled to 32,440 feet TVD. According to Guy at Transocean they've gone down to 35,000 feet TVD. And Transocean is building ships that will drill to 40,000 feet TVD.
Furthermore, 275 degree heat is no problem for oil: Brazil Oil Trapped by 500-Degree Heat
For more of Mr. Deffeyes's pseudoscience see here: The Many Wrong Predictions Of Ken Deffeyes.