Offshore Oil and Gas

from Kid's http://www.eia.doe.gov/kids/energyexplained/sources/non-renewable/offshore.html, last revised: June 2008.

Offshore Drilling

Petroleum and natural gas are fossil fuels. They are derived from the remains of plants and animals (diatoms) that died millions of years ago, were buried and compressed. Petroleum and natural gas are nonrenewable energy sources because they take millions of years to form. In the Exclusive Economic Zone (EEZ), there are 30 basins that have been identified as containing oil and gas reserves. A few of these are already producing oil and gas. It is estimated that 30% of undiscovered U.S. gas and oil reserves are in the Outer Continental Shelf (OCS).

Offshore Oil Rig

Source: Stock photography (copyrighted)

The first oil well was drilled in 1859, and by 1897 the first offshore oil well was drilled. It was at the end of a wharf, 300 feet out into the Pacific Ocean in Summerland, California. In 1953, individual States were given jurisdiction over lands within three miles of their shoreline, allowing the Minerals Management Service (MMS) to lease the rest of the EEZ and regulate recovery efforts. Early offshore drilling was generally limited to areas where the water was less than 300 feet in depth.

for Oxygen only, switch to picture of offshore rig without Energy Ant. Plus add link to site with numerous photos of offshore rigs.(Stacy)

Offshore drilling looks very different today, supplying about 25% of the Nation’s natural gas production and about 24% of its oil production. Drilling rigs can now operate in water as much as two miles deep. Some drilling platforms stand on stilt-like legs that are embedded in the ocean floor. These huge platforms hold all the drilling equipment needed, as well as housing and storage areas for the work crews.

Floating platforms are used for drilling in deeper waters. These self-propelled vessels are anchored to the ocean bottom with huge cables and anchors. Once the wells have been drilled from these platforms, the production equipment is lowered to the ocean floor, sealed to prevent leakage. Wells have been drilled in 10,000 feet of water using these floating rigs.

Offshore oil producers are always taking precautions to prevent pollution, spills and significant changes to the ocean environment. Since 1975, drilling in the EEZ has had a safety record of 99.999% meaning that only .001% of the oil produced has been spilled. Offshore rigs are even designed to withstand hurricanes. Offshore production is costly — many times as expensive as land-based production. When wells no longer produce enough to be financially worthwhile, they are sealed and abandoned.

Nearly all current leasing and development activity occurs in the central and western Gulf of Mexico. There, more than 4,000 platforms are operating in waters up to 6,000 feet deep, and many rigs are drilling in waters approaching 10,000 feet. Right now most of the active wells and proved reserves are in the Gulf of Mexico. There are also 43 wells off California's coast.