I'm wondering what happens beneath the earth while we keep drilling for oil. If you know that we drill millions of liters a day, what does this do to the mantel of our earth?
What a coincidence. This question was asked and answered in today's Washington Post. The answer was: Yes, it leaves some cavities that may eventually collapse. But we pump far more water out of the earth's surface and we have been doing it for a much longer time, and the effect is much more serious. The south central part of Arizona is already sinking. That's the Phoenix and Tucson metropolitan areas, where most of the people in the state live.
. . . . wouldnt it take millions of years to make more crude?
There will never be more crude. That was a once-in-a-planet's-lifetime opportunity. Petroleum is dead trees that have been allowed to lie around undisturbed for about three hundred million years. The reason that they remained undisturbed for this incredibly long time is that none of the organisms that lived in the Carboniferous Era had an enzyme that could break down
lignin, the rigid substance that gives trees their strength. In other words,
nothing could eat or decay wood.
This is not the case any more. When a potential source of nutrition is available, evolution often eventually steps in and provides us with an organism that can make use of it. In this case it is certain species of fungus, including the ubiquitous common brown button mushroom,
Agaricus bisporus. You see huge colonies of this fungus in a walk through the forest, growing on dead trees and happily converting their wood into nutrients, using the lignin modifying enzymes (LMEs) which their body chemistry evolved over time. Some bacteria also have LMEs.
The petroleum in existence now is all there will ever be. In fact, evolution is working on that too: There are now bacteria that can eat petroleum. They evolved in the ocean after the start of offshore oil drilling, because no matter how carefully the process is performed, there is always a little
seepage burbling up on the sea floor. In fact, every single year twice as much petroleum seeps into the Gulf of Mexico this way as was spilled into the Arctic by the Exxon Valdez. These bacteria are amazingly efficient: the half-life of any blob of petroleum in the ocean is only three days! The residual "plume" in the Gulf from the BP spill will, for all practical purposes, vanish in a few more weeks without any human intervention.
Since these bacteria evolved to live on the ocean floor, they are actually more effective in colder water. At 40 degrees (5C) they consume oil twice as fast as at 70 (27C).
