Petroleum is found in many places around the world: the largest reserves, however, are located in Saudi Arabia, Venezuela, Canada, Iran and Iraq. Petroleum reserves may span vast areas of land. They are found on land and at sea, and some locations have a wealth of reserves in one central spot, which are called petroleum plays.
Petroleum, like natural gas and coal, is a nonrenewable resource. Petroleum deposits accumulated over a long period, taking millions of years to form. It does not regenerate, which means that once supplies are depleted, petroleum deposits will disappear. Some locations are more lucrative sources of petroleum than others, although this substance is found around the world. The largest land reserves are located in the Middle East, while large ocean supplies of petroleum lie off the coast of Alaska, around Northern Europe and off the shores of Russia. Petroleum reserves occur naturally, and there are no synthetic methods of creating this product. Given the increasing scarcity of the substance, however, many governments, including that of the United States, harbor petroleum preserves. In the northeast, a large reserve of nearly 200 million barrels of petroleum is preserved by the federal government. The navy and other military branches have special reserve deposits of petroleum as well.