
Geology of Oil and Natural Gas

Despite the popular belief that oil comes from dinosaurs, in reality it originates from the decaying remains of countless microscopic creatures that died, fell to the ocean floor, and became buried under thousands of feet of sediment. The heat and pressure of the overlying sediments changed the chemical make-up of the organisms into crude oil. Natural gas, which is composed mainly of methane, is a by-product of this slow process and is found both with oil or by itself. Crude oil and natural gas are together referred to as petroleum.

Another type of oil resource occurs when oil makes its way to the surface forming a geologic feature known as tar sands. The Hartselle Sandstone in northwest Alabama is a prime example of such a surface oil field. Although geologists believe Alabama's tar sands have future commercial use, most of the state's known petroleum reserves are located underground.
Discovery of Oil and Gas Reserves
The world's first oil discovery occurred in Pennsylvania in 1859. Chemists found they could refine the crude oil into certain components that were useful. The first of these refined products to find widespread use was kerosene, which quickly replaced whale oil as lamp fuel. Later, gasoline and other fuels were refined to power the engines of the fuel-thirsty twentieth century. By the end of World War II, the rapid demand for refined products meant that the hunt for oil spread quickly across the United States and the world.
Traces of petroleum, in the form of natural gas, were first discovered in Alabama in Morgan and Blount Counties in the late 1880s, and by 1902, natural gas was being supplied to the cities of Huntsville and Hazel Green. In 1909, a small discovery by Eureka Oil and Gas at Fayette fueled that city's streetlights for a time, but no natural gas was recovered anywhere in the state for several decades afterward.
In 1945, the state legislature created the Alabama Oil and Gas Board (AOGB) to regulate the oil and gas industry in the state. When a discovery is made, the oil companies are required to take their information before the AOGB at a public hearing. The AOGB then issues special rules concerning the regulation and production of the petroleum; assures the rights of mineral owners; and ensures that environmental protection laws and regulations are followed. With the creation of the AOGB, the legislature appointed Walter B. Jones, Alabama's third state geologist, as its supervisor.

In 1955 at Citronelle in Mobile County geologist Everett Eaves and legendary wildcatter Chesley Pruet established the most famous oil well in the state's history, the No. 1 Donovan, discovering the biggest oil field east of the Mississippi River at the time. Citronelle produced 160 million barrels of oil from the Rodessa Sandstone, 12,000 feet down, becoming Alabama's only "giant" oil field, which is a field that produces more than 100 million barrels. Expanding to 500 wells, Citronelle sparked a drilling flurry in south Alabama, but the results were mostly disappointing until the mid 1960s, when explorers made a series of discoveries in Jurassic rocks, from 12,000 to 20,000 feet below the surface. These discoveries, spearheaded by Pruet and his partner, geologist Dudley Hughes, added hundreds of millions of additional barrels of oil to Alabama's discoveries.

During the post-war years, the oil industry in Alabama followed national trends, going through many cycles of ups and downs, depending on the price of oil. When foreign oil began to flow in vast amounts into the nation in the late 1950s and 1960s, oil prices fell and drilling slowed. In 1973, however, the Arab Oil Embargo sent prices soaring, and exploration picked up again. Many new oil and gas fields were discovered, among them the huge finds in Mobile County at Hatters Pond by Getty Oil Company, at Chunchula by Union Oil, and other big finds in Escambia County.
In the late 1980s, Alabama moved into the world spotlight as a consortium of companies, in concert with the federal government and the University of Alabama, began producing methane gas from coal beds in the Black Warrior Basin. Within a few years, gas companies sank thousands of shallow wells across west Alabama, adding two trillion cubic feet of gas to the state's reserves. Other states and foreign countries closely watched the coal-bed methane technology develop in Alabama and applied it throughout the world.
Oil and Gas Prospecting and the Environment

In 1978, with protections in place to preserve the bay's ecology, Mobil moved in a huge offshore rig. They drilled more than 21,000 feet into an ancient desert called the Norphlet Sandstone and discovered the largest natural gas field east of the Mississippi, the Lower Mobile Bay–Mary Ann Field. The discovery formed the core of offshore development that eventually located six trillion cubic feet of reserves and as of 2007 has sent $2.1 billion worth of royalties to Alabama's Heritage Trust Fund, which uses the interest from the funds to help pay for the state's education and infrastructure needs. The fund was the first of its kind in U.S. history. Oil and gas activity in Mobile Bay and the nearby Gulf of Mexico waters stands today as a global environmental standard for offshore drilling and production operations.
Current Oil and Gas Production in Alabama

Oil and gas is still being found in Alabama, and geologists believe new opportunities exist in the hard shales of the deep Black Warrior Basin beneath Pickens and Tuscaloosa Counties and in the thick fractured shales of St. Clair and neighboring counties.
Additional Resources
Cockrell, Alan. Drilling Ahead: The Quest for Oil in the Deep South, 1945-2005. Oxford: University Press of Mississippi, 2005.
Additional Resources
Cockrell, Alan. Drilling Ahead: The Quest for Oil in the Deep South, 1945-2005. Oxford: University Press of Mississippi, 2005.
Hughes, Dudley J. Oil in the Deep South: A History of the Oil Business in Mississippi, Alabama, and Florida, 1859-1945. Oxford: University Press of Mississippi, 1993.