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Drilling for Oil at 40,000 Feet Deep

The lifeblood of the world's economy is petroleum. Nearly every modern convenience in some way owes its existence to fossil fuels. Energy companies are therefore justified in going to extreme lengths to tap new reserves of crude oil. Most of the Earth's oil is trapped far underground inside porous rocks. As drilling operations continue to empty the shallowest fields, company geologists look to deeper sources. These deep oil fields represent a technically challenging goldmine if they can be safely brought to the surface.

Drilling Technology
- Crude oil exists within sedimentary rocks like limestone and sandstone, much like water in a sponge. Finding these reservoirs of oil requires mapping the rock layers using seismic technology. Geologists send shock waves through water or earth and record the echoes with sensitive microphones. Discovering oil at greater depths naturally poses a greater challenge. The drill bit's path is carefully mapped out so as to avoid fault lines, air pockets and other hazards. As the oil is drawn up, workers must ensure that the drill hole remains clear of muck and debris.
Untapped Reserves
- Geologists and energy analysts believe that most of the world's easily accessible oil has been discovered. Shallow, rich oil fields in Saudi Arabia and Alaska are on the decline. The deep reserves -- 30,000 to 40,000 feet below sea level -- represent the next frontier in petroleum production. Scientists working for the United States government have estimated that 40 billion barrels of oil may exist deep underneath the Gulf of Mexico.
Heat and Pressure
- Drilling at depths of 8 miles or more presents hazards that shallow wells never experience. The drill bit must pass through many layers of rock, each one of a different composition. The movement from one layer into the next puts enormous stress on the drill. Also, the rocks deep underground become hotter with depth. The oil trapped 30,000 feet below sea level may reach temperatures of 400 degrees Fahrenheit. If hot oil comes in contact with cold sea water, the entire operation can be derailed.
Dangers
- The Deepwater Horizon oil spill in the Gulf of Mexico demonstrated the risks involved in oil drilling operations. The workers at the well site put themselves in harm's way each day. A rig pumping thousands of barrels of oil to the surface is essentially a powder keg of flammable material. Powerful hurricanes can damage or destroy offshore platforms. Large oil spills have environmental and economic consequences that are difficult to measure. The Deepwater Horizon spill, one of the largest ever, devastated the Gulf of Mexico fishing and tourism industries.

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