How Did Oil Get into Oil Wells?
The oil we get from oil wells today was formed from the remains of plants and animals that lived millions of years ago. At that time, places where we find oil were covered by seas. Many plants and animals lived in the sea water and fell to the ocean bottom when they died. Sand and mud drifted down, covering their remains.
Over the centuries, the sand and mud that held this organic matter turned to rock. All that remained of the ancient sea life were drops of oil and bubbles of gas. Ages later, deep wells were drilled to reach the oil that had collected in the rocks.
Crude oil is a smelly, yellow-to-black liquid and is usually found in underground areas called reservoirs. Scientists and engineers explore a chosen area by studying rock samples from the earth.
Measurements are taken, and, if the site seems promising, drilling begins. Above the hole, a structure called a ‘derrick’ is built to house the tools and pipes going into the well. When finished, the drilled well will bring a steady flow of oil to the surface.
Nature has been transmuting dead life into black gold for millions of years using little more than heat, pressure and time, scientists tell us. But with gas prices spiking more than $1 per gallon in the United States this year and some experts predicting that the end of oil is near, scientists still don’t know for sure where oil comes from, how long it took to make, or how much there is.