Historically, offshore drilling began by extending known coastal oil- and gas-producing trends out into the ocean. For this reason, most US offshore drilling has taken place offshore Louisiana, Texas, California, and Alaska, areas with coastal onshore oil and gas fields. :"Possibly in some future age, when all known petroleum fields shall have been drained of their richness, oil men may seek refuge in King Neptune's realm." ::-
Oil & Gas Journal, 24 June 1915
Alaska The first federal lease sale offshore Alaska was held in 1976. Alaska produces oil and gas from offshore areas in the
Cook Inlet and the
Arctic Ocean.
Endicott Island is an artificial island built to produce oil from beneath the
Beaufort Sea. There are currently four artificial islands being used for drilling. By Executive Order dated April 28, 2017, the
Bureau of Ocean Energy Management will begin selling offshore leases in 2019.
California Offshore drilling began in California in 1896, when operators in the
Summerland Oil Field in
Santa Barbara County followed the field into the ocean by drilling from piers built out over the ocean. Leasing California state seabed is controlled by the State Lands Commission, which halted further leasing of state offshore tracts after the
Santa Barbara oil spill in 1969. In 1994 the California legislature codified the ban on new leases by passing the California Coastal Sanctuary Act, which prohibited new leasing of state offshore tracts. The federal government has had no new lease sales for offshore California since 1982. Offshore drilling has continued from existing platforms in state and federal waters. State offshore seabed in California produced of oil per day, and federal offshore tracts produced of oil per day in November 2008. State and federal offshore tracts together made up 16% of the state's oil production. Notable offshore fields include the
Ellwood Oil Field, which is partially onshore and partially offshore, and the
Dos Cuadras Field, source of the 1969 spill, which is entirely within the federal zone.
Gulf of Mexico See
Offshore oil and gas in the US Gulf of Mexico The western and central
Gulf of Mexico, which includes offshore Texas, Louisiana, Mississippi, and Alabama, is one of the major petroleum-producing areas of the United States. In 2007, federal leases in the western and central Gulf of Mexico produced 25% of the nation's oil and 14% of the nation's natural gas. In 2008, federal leases in the Gulf of Mexico produced of oil, down from in 2002; however, due to new deep-water discoveries, the MMS projects that oil production from the Gulf of Mexico will increase to per year by 2013. Major fields include
Atlantis Oil Field, and the
Tiber oilfield (discovered 2009) and others in the
Keathley Canyon protraction area. Notable oil platforms include
Baldpate,
Bullwinkle,
Mad Dog,
Magnolia,
Mars,
Petronius, and
Thunder Horse. Notable individual wells include
Jack 2 and
Knotty Head. The eastern Gulf of Mexico, which includes offshore Gulf Coast Florida, has never been a petroleum-producing area due to federal and state restrictions on exploration. Offshore platforms currently exist as far east as to near the Florida-Alabama border.
East Coast In the late 1970s and early 1980s oil companies drilled 51 exploratory wells on federal leases on the outer continental shelf of the Atlantic coast. All the leases have now reverted to the government. A 1996 study by the MMS estimated undiscovered conventionally recoverable resources in Atlantic federal waters to be of oil and gas.
Pacific Northwest Coast The Sunshine Mining Co. made Washington state’s first oil discovery in July 1957, at a location 1.4 miles south down the coast from Ocean City. The discovery was on a state lease, and was below mean high tide, which made it an offshore well. Additional wells were drilled in the area, but none produced any oil. The discovery well made 11,032 barrels of oil before it was plugged in 1959. In 1964, the federal government leased tracts totaling in offshore
Oregon and
Washington. Oil companies drilled six tests offshore Washington (three in state waters and three in federal waters) and seven tests in federal waters offshore Oregon. The OCS P-0130 well drilled offshore Oregon by Union Oil in 1966 was described as having "potential for commercial gas production", but none of the wells were completed as producers, and the federal leases expired in 1969. Farther north, in Canadian waters,
Shell Canada drilled 14 wells offshore from
Vancouver Island from 1967-1969. None were successful. Canada has had a federal moratorium on offshore drilling on its west coast since 1972.
Great Lakes The lakebeds under the US portion of the
Great Lakes are owned by the adjacent states. The only state that has allowed oil and gas drilling beneath the Great Lakes in recent years has been
Michigan, and that only by
directional drilling from onshore surface locations. All oil and gas drilling, either on or directionally beneath the Great Lakes, has been banned by federal law since 2002. The Canadian side of
Lake Erie has 480 producing gas wells in the lake. Gas production in Canadian Lake Erie waters dates back to 1913; more than 2000 wells have been drilled to the Clinton Sand, up to a few miles from the US side of the lake; the same formation produces gas from many onshore wells on the US side, but there are no wells in the US portion of the lake. The province of
Ontario, where the offshore wells are located, allows gas wells, but not oil wells, in offshore Lake Erie. Ontario allows oil production from below the lake only from wells drilled directionally from onshore surface locations; a number of such directional wells are producing oil from beneath Lake Erie in the Goldsmith/Lakeshore Field. A gas well to the Medina Group was drilled in 1958 in Pennsylvania state waters in Lake Erie. The only state that has current oil and gas production from beneath the Great Lakes is Michigan. Michigan has 13 oil and gas wells that produce from below
Lake Michigan, all drilled directionally from surface locations on shore. Directional drilling beneath the Great Lakes is now banned. The US Geological Survey has estimated that of recoverable petroleum liquids and of recoverable natural gas underlie the US portion of the Great Lakes. Petroleum potential was given to all of the lakes except
Lake Superior. The majority of the natural gas (3.0 TCF) is thought to underlie Lake Erie. ==Restrictions on offshore drilling==