Today geologists and petroleum engineers employ more tried and true methods. While these methods narrow the search tremendously, a person still has to drill a exploratory well, or wildcat well , to see if the oil actually exists. Success brings visions of gushers soaring skyward, however today wells are capped before this happens. Rotary drilling works at much greater depths , and involve sinking a drill pipe with a rotating steel bit in the middle. Off-shore drilling involves huge semisubmersible platforms which lower a shaft to the ocean floor, containing any oil which is located.
All crude oil contains some amount of methane or other gases dissolved in it.
Once the drilling shaft makes contact with the oil it releases the pressure in the underground reservoir. Just like opening a can of soda pop , the dissolved gases fizz out of solution pushing crude oil to the surface . To get better recovery water is often pumped into the well, this forces the lighter oil to the surface. The addition of surfactant allows even more oil to be recovered by preventing much of it from getting trapped in nooks and crannies. Yet, it is impossible to get all of the oil out of a well .