Non-Renewables: Offshore Oil & Gas

That the oceans harbor oil and natural gas reserves has long been recognized, but finding and extracting those resources have proved challenging in the marine environment. The first offshore oil well was drilled off the coast of California in 1897 and rapid expansion of the industry occurred thereafter, however early drilling was limited to depths of only about 100 meters. Modern technology today allows recovery from water over three kilometers deep.

The United States and the countries of Northern Europe have a strong dependence on oceanic fossil fuels. In recent years, offshore (or OCS, standing for Outer Continental Shelf) oil and gas accounted for about a quarter of U.S. domestic supply; it is estimated that 30% of undiscovered oil and gas reserves in the U.S. exist as offshore fields. Some areas, like the Gulf of Mexico and the North Sea, are dotted with fixed oil rigs able to pump massive amounts of oil and gas to shore-based processing facilities. Floating rigs are also used in offshore areas.

Naturally seeping oil can similarly be recovered. When oil escapes from deep sea fields, it rises to the surface, sometimes in significant quantities. In the Santa Barbara Channel off California (USA), for instance, 150 barrels of oil seep out per day. In addition, millions of cubic meters of gas seep out and escape into the atmosphere. In 1982, oil and gas companies built two huge steel pyramids to place over the seeps in California and recover otherwise wasted energy resources. Such seep recovery efforts have subsequently sprung up in many other parts of the globe.

Many countries have recognized the potential of offshore reserves but have curbed oil exploration and extraction activities in sensitive coastal areas. A moratorium has been in place in the Canadian eastern seaboard for decades, and in 1990, President George H. Bush established an OCS moratorium in parts of Aleutian Islands, Pacific Coast, Eastern Gulf of Mexico, and the North Atlantic within U.S. jurisdictions. The latter restriction was renewed by President Clinton and remained in effect until this year [2007]. Increasingly, local jurisdictions have tried to limit offshore oil and gas activity. In the U.S., coastal states have exerted their jurisdictional authority, hoping to reduce risks of environmental catastrophe and reduce environmental effects within state waters (from 0-3 miles offshore).

Recent research has highlighted the potential for seabed-based methane hydrates to meet some energy demands. Methane hydrates are ice-like deposits found in the top few hundred meters of sediment in certain deep ocean areas of the continental margins. The methane gas is actually trapped in ice cages, and can be easily extracted from it, but removing the hydrates from the seabed has proved problematic. Russian energy experts have tried using antifreeze to remove the methane from hydrates, and recent research has focused on trying to pipe warm surface water down to melt the hydrates and then piping the gas to the surface using a parallel set of pipes. However, melting the hydrates to release methane may cause the seafloor to become unstable, and could have untold ecological impacts as well. In addition, if methane is lost to the atmosphere during the process, it could add to the global warming phenomenon, since methane is a potent greenhouse gas.

Nevertheless, methane hydrates have caused excitement in the energy field. Some researchers also believe that there is free-flowing methane gas beneath the several hundred meters deep hydrate layers.¹ The National Energy Education Project (US) suggests that methane hydrates may contain over 30 times the existing natural gas resources and reserves worldwide.²