Offshore Oil and Natural Gas Overview
Offshore Oil & Gas production of the U.S. Outer Continental Shelf (OCS) and state waters is presented with industry definitions and links to source information. The searchable database below includes the crude and condensate oil and natural gas volumes and prices for all offshore regions and producing states, as well as national totals, from 1981 to 2021.
Offshore Oil Production Data
The oil and gas production visualizations below show production values for the entire US. Users may search by region, jurisdiction (state or federal waters), and year. For more information on how to use the NOEP Apps, view the manual.
Offshore Natural Gas Production Data
Abandoned Oil Rigs
The environmental problems associated with oil exploration and production do not simply disappear when wells shut down. They often leak oil unless properly plugged and shifting geological conditions may reopen a well. In these cases, abandoned wells will leak leading to environmental damage and public health impacts. In many cases, the firms which drilled a well no longer exist, making cleanup difficult. Furthermore, costs in these cases are borne by the public.
Given its long history of oil exploration and the sheer number of wells in the region, the Gulf of Mexico is particularly impacted by the problems associated with abandoned wells. Using data from the Bureau of Ocean Energy Management, the National Ocean Economics Program has begun tracking abandoned oil wells using GIS maps. The original data is also available for download. In order to make best use of the BOEM data, users should download the data dictionary.
NOEP Offshore Oil & Natural Gas Definitions and Description
The Offshore Oil & Gas search page provides an easy way to locate and compare production numbers by year and computed dollar value for:
- State and Federal regions
- Total U.S. production
- Associated wellhead price (gas)
- First purchase price (oil) by year, region
Oil and natural gas production in the United States takes place in state waters and on the Outer Continential Shelf (OCS). The Bureau of Ocean Energy Management manages the leases for the OCS regions. Offshore oil production in Federal waters (on the OCS) is limited to the Gulf of Mexico, California, and, Alaska. The Gulf of Mexico includes the federal waters off Texas, Louisiana, and Alabama. Texas, Louisiana, California, and Alaska also produce oil and natural gas in their state waters.
Oil and Gas comes out of the ground in different forms:
- Crude oil is normally classified as light, medium, heavy, or bitumen (tar sands) based on its physical properties. Generally, heavy oil is thicker and more viscous than light oil and therefore must be mixed with a lighter oil or condensate before it can flow in a pipeline.
- Condensate is a liquid hydrocarbon, which is associated with 'wet gas.' These production numbers are included in the NOEP database when available.
- Natural gas is a combustible mixture of hydrocarbon
gases, primarily methane. Other mixtures include ethane,
propane, butane, and pentane. (The propane and butane, which
can account for up to 20% of the hydrocarbons present, are
removed and sold separately.)
- Dry natural gas is almost purely methane, with most of the other hydrocarbons removed.
- Wet natural gas has hydrocarbons. See Oil & Gas Terms for more information.
NOEP Offshore Oil & Gas data are collected from the Bureau of Ocean Energy Management, the Energy Information Agency (EIA), and state agencies having oversight of the offshore natural resources and minerals production in their waters.
These data are available on the website for most of the producing coastal states from 1970 to 2010, with a few exceptions:
- Alabama state offshore production did not begin until 1987.
- Mississippi does not have state offshore production.
- Texas combined its onshore and offshore production data until 1980.
- Alaska OCS began producing in 2001 with the NorthStar project.
- First Purchase Pricing became available in 1978. NOEP uses the U.S. average price for pre-1978 pricing.
Yearly regional oil and gas pricing information also is available:
- Natural Gas: Wellhead Price per mcf (one thousand cubic feet measured at standard pressure and temperature condition)
- Oil: First Purchase Price per bbl (42 U.S. gallons measured at 60°F)
For more information about oil and gas industry terms see: Oil & Gas Terms
Oil and Gas Terms
API: American Petroleum Institute
bbl, Barrel: In the energy industry, a barrel is 42 U.S. gallons measured at 60ºF.
Casinghead Gas (or oil well gas): Natural gas produced along with crude oil from oil wells.
Condensate: A low-density, high-API gravity liquid hydrocarbon phase that generally occurs in association with natural gas. Its presence as a liquid phase depends on temperature and pressure conditions in the reservoir allowing condensation of liquid from vapor. The production of condensate reservoirs can be complicated because of the pressure sensitivity of some condensates. During production, there is a risk of the condensate changing from gas to liquid if the reservoir pressure drops below the dew point during production. Reservoir pressure can be maintained by fluid injection if gas production is preferable to liquid production. Gas produced in association with condensate is called wet gas. The API gravity of condensate is typically 50ºF to 120ºF.
Crude Oil: Liquid petroleum as it comes from out of the ground as distinguished from refined oils manufactured out of it.
Dry Natural Gas: See Natural Gas.
FPP or First Purchase Price (oil): The marketed first sales price per bbl of domestic crude oil, consistent with the removal price defined by the provisions of the Windfall Profits Tax on Domestic Crude Oil (Public Law 96-223, Sec. 4998 (c)).
mcf: One thousand cubic feet of natural gas measured at standard pressure and temperature conditions and obtained at the surface as such.
National Offshore: The total amount produced offshore in U.S. waters. State offshore totals and Federal OCS totals combined.
Natural Gas: A naturally occurring mixture of hydrocarbon and non-hydrocarbon gases in porous formations beneath the earth's surface, often in association with petroleum. The principal constituent is methane.
- Dry gas- Natural gas that occurs in the absence of condensate or liquid hydrocarbons, or gas that has had condensable hydrocarbons removed.
- Wet gas- Natural gas that contains less methane (typically less than 85% methane) and more ethane and other more complex hydrocarbons.
Outer Continental Shelf (OCS): The offshore Federal domain is greater than 3 miles from coastline for most states, beyond 3 nautical leagues from the Texas coast.
Pool: An underground reservoir containing, or appearing to contain, a common accumulation of oil or gas where each zone of a general structure completely separated from any other zone in the structure is covered by the term 'pool'.
State Waters Offshore: Offshore waters from 0-3 miles along a state's coastline except Texas, which extends up to 3 nautical leagues, or roughly 10 miles, out into the Gulf of Mexico.
Total Oil: Total liquids produced; crude oil and condensate combined.
Wellhead Price (Natural Gas): The value at the mouth of the well. In general, the wellhead price is considered to be the sales price obtainable from a third party in an arm's length transaction. Posted prices, requested prices, or prices as defined by lease agreements, contracts, or tax regulations should be used where applicable.
Wet Natural Gas: See Natural Gas.