Many geology textbooks show side views of oil wells. They show wells drilling down into pools of oil that rest in bowl-shaped areas of impermeable rock. The implication is that the oil has dribbled down from endless buried forests, jungles, and piles of decaying dinosaurs. This magically appearing oil filled the bowl over billioins of years, and drillers pump that oil from the bowl. Soon, they insist with near-religious fervor, the bowls of oil will all run dry, and we will finally run out of oil.
The opposite is true. Oil and natural gas is continually being produced and is being pushed up from far, far below the earth’s surface. The layers of less permeable rock actually trap the rising oil and natural gas underneath them. Successful drillers find those fuels beneath layers of less permeable rock and clay that keeps oil and natural gas from being pushed to the surface by the awesome power of heat generated by the decay of radioactive uranium and thorium deep within the earth.
In the cases above, the oil and natural gas have actually been pushed up from below, until they are trapped by less permeable rock above them. It’s easily seen that the oil floats on water below ground, just as it does above.
