The Making of Oil
Birth of a Reservoir

Movement of the Continents 

The creation of an oil reservoir begins with the movement of continents over millions of years. Today's North Sea reservoirs were born when this push and pull of land formed a valley near the equator.

Over time, the valley moved thousands of miles. It was flooded to become a shallow sea, then became a swamp, later a desert and then back to a sea again. When water flooded the area, it produced organic matter than would eventually become oil.

The continents are still moving today, and the valley that became the North Sea continues to subside, collecting organic material that, over the next million years, may eventually become oil.