The precise amount of oil and gas which is recoverable from the U.S. continental shelf is unknown. Some sources of hydrocarbons, recoverable from known reservoirs under present economic and operating conditions, are called "demonstrated reserves". With sound geologic and engineering knowledge, predictability about the existence and amount of these reserves is reasonably accurate. "Undiscovered recoverable reserves" are analyzed through geologic, seismic, and other types of exploratory methods. At best, the results of such tests yield educated guesses that, within broad probability levels, certain quantities of recoverable oil and gas exist. It is only when actual drilling occurs that estimates take on greater degrees of accuracy. Within the last several years, the USGS has been reducing its estimates of offshore oil and gas reserves. Table 1 presents the Survey's published data of June, 1975.26 U.S. Oil and Gas Production from the OCS The primary source of U.S. offshore oil and gas production comes from the Gulf of Mexico. In 1974, the Gulf accounted for approximately 70 percent of the offshore oil produced and over 95 percent of the offshore natural gas produced. Most of this hydrocarbon production now comes from the federally-owned Outer Continental Shelf. Alaska.... TABLE 1.-U.S. OFFSHORE OIL AND NATURAL GAS RESERVES AND RESOURCES Gulf of Mexico. Atlantic... Total_ Statistical mean.. Note: Undiscovered potential resources of oil, gas, and liquid gas have been estimated to range from 95 percent to 5 percent probability for all areas. Source: U.S. Department of the Interior. Geological Survey. The undiscovered potential resources estimates are for seabed area to a depth of 200 meters. Potential oil and gas from the continental slope and rise are not included in the estimates. 26 More recent USGS figures of Jan. 1, 1976 put the remaining, discovered, recoverable reserves in the Gulf of Mexico and offshore southern California at 4.727 billion barrels of oil and 34.276 trillion cubic feet of gas. TABLE 2.-OIL AND CONDENSATE TOTAL OFFSHORE "STATE" AND "FEDERAL OCS" Source: Bureau of Mines, Alaska Scouting Service, Conservation Committee of California, Louisiana State Mineral Board, Louisiana Department of Conservation, Texas Railroad Commission. Louisiana and Texas are estimated in part. Printed in U.S. Geological Survey, June 1977, Harris, Walter M., Piper, Sharon K., McFarlane, Bruce E., "Outer Continental Shelf Statistics." |