When we think about oil, it’s easy for our minds to drift to faraway, hot places: pumps in Texas, wars in the Middle East, rigs hundreds of miles out in the Gulf of Mexico. But for Mobilians, the oil is right beneath our feet — literally — and it has been for hundreds of millions of years.
Oil has been found in places not so distant. In fact, Citronelle has been dubbed “the oil capital of Alabama” ever since the discovery of an enormous oil field there in 1955. And some think there’s still more to be found.
This month, learn all about how oil has affected Mobile and how a natural gas reserve below Mobile Bay forever changed the oil industry.
A CRUDE AWAKENING As oil forms deep underground, natural gas is created as a byproduct of the slow process. Both oil and natural gas are called “petroleum.” “Crude oil” is oil taken straight from the ground before being refined into products like gasoline. A place where oil is suspected to be found is called a “prospect, ” and if you grew up watching “The Beverly Hillbillies, ” you already know that oil is nicknamed “black gold” and “Texas tea.”
DINOS ROCK (BUT THEY DON’T MAKE OIL) Sorry to break it to you, but oil doesn’t come from dinosaurs, despite what your fourth-grade teacher said. Instead, it is formed from the countless microscopic creatures that have died and fallen to the ocean floor (think “fossil fuel”). Over millions of years, the heat and pressure of being buried underneath thousands of feet of sediment transform these organisms into crude oil. The oil then slowly migrates through microscopic rock pores until becoming trapped in a fault. Over time, this petroleum pool grows larger and larger, resulting in an oil field.
DRILL, BABY, DRILL On average, an oil rig drills about 6, 000 feet (or, about 8 RSA towers deep) into the earth’s crust to harvest crude oil. Oil is usually measured in barrels, and if you want to be that obnoxious know-it-all at trivia night, remember that one barrel contains 42 gallons.
THE CARBON FACTOR In short, oil is useful because it contains “hydrocarbons, ” organic compounds containing hydrogen and carbon that contain a lot of energy. Hydrocarbons come in chains of various lengths and structures that all have different properties and are therefore useful in different ways. This explains where we get various products, such as gasoline, kerosene and petroleum gas.
Our history in oil
- The majority of Alabama’s oil comes from two sedimentary basins, the Black Warrior Basin in the northwest and the Interior Salt Basin in the southwest (underneath Mobile and Baldwin counties). Alan Cockrell, a retired petroleum geologist in Mississippi, explains, “Geologists use the term ‘basin’ to describe a broad area where layered sedimentary rocks sag thousands of feet downward into a bowl shape.” The rocks that make up the Interior Salt Basin are roughly 200 million years old.
- When oil was struck in Citronelle in 1955, it was, at the time, the biggest oil field ever discovered east of the Mississippi River. Producing 169 million barrels of oil, the Citronelle site became Alabama’s only “giant” oil field, a designation given to fields that yield more than 100 million barrels.
- In 1978, Mobil Oil Corporation discovered one of North America’s largest natural gas reserves — right underneath Mobile Bay. But the significance of the discovery extends far beyond Alabama. In an effort to protect the Bay’s valuable ecosystem, state regulators and environmental groups subjected Mobil to the strictest environmental supervision ever enacted, even reprimanding workers who spit over the side of the rig. Today, the example set in Mobile Bay stands as the global standard for offshore drilling.
- Unfortunately, an area known for its offshore drilling is also likely to be known for its oil-related disasters, most notably the Deepwater Horizon spill in 2010 and the recent Shell oil spill off the coast of Louisiana in May of this year.
- Oil and gas are still being found in the state. Today, Alabama is among the top 15 state producers of natural gas and a top 10 producer of oil. According to the Encyclopedia of Alabama, “the state produces almost $2.5 billion worth of oil and gas annually.”
Text by Breck Pappas