PRESTO III is a drilling simulation model used by the Minerals Management Service (MMS) to calculate estimates of undiscovered, economically recoverble oil and gas on the Federal Outer Continental Shelf (OCS). The model uses risk analysis to simulate drilling of user defined prospects. Output estimates are given as probability distributions for four commodities: oil, associated and nonassociated gas, solution gas, and condensate. The program also incorporates four levels of risk and separate economic thresholds at the area, basin, and prospect levels.
A grouped-prospect play assessment of the Federal OCS using PRESTO III was recently conducted as part of a joint National Resource Assessment involving MMS and U.S. Geological Survey personnel. The results of this study will be used as a baseline in support of the MMS offshore leasing program and for national strategic energy planning.
Estimates of undiscovered oil and gas are vital to essential long-range national planning. The Federal Government's offshore oil and gas leasing program depends heavily on projections of the remaining amounts of economically recoverable hydrocarbon resources on the Outer Continental Shelf (OCS). The pace of development of these resources affects national security, the economic health of a large sector of the economy, the balance of trade, and many other important national issues.
The Minerals Management Service (MMS) develops estimates of undiscovered, economically recoverable hydrocarbons in support of the OCS leasing program and for planning purposes. The estimates are used in a number of public and internal documents related to leasing, such as sale-specific Environmental Impact Statements (EIS's), the Biennial Report to Congress (Section 606, OCS Lands Act), formu1ati.on of the 5-year leasing program, publications, and interagency memoranda.
The EIS's for specific lease sales and events, such as the development of a 5-year leasing program, use the estimates as the basis for oil-spill models, sale alternatives and deferral options, or for any other requirement for which the potential resources in specific areas must be known. Estimates provided in the Biennial Report to Congress are used by the legislature (and others) for national strategic and economic planning.
A major effort involving MMS and U.S. Geological Survey (USGS) personnel was conducted within the past 2 years to develop resource estimates for the entire offshore and onshore United States. This National Oil and Gas Resource Assessment provided economic and economics-free, conventionally recoverable resource estimates. The estimates and the methodology used to develop them are currently under review by the National Academy of Sciences and the Association of American State Geologists. This is the first time MMS and USGS have cooperated on a study of this scope. The methodologies used and the offshore results are the subject of this and the two succeeding papers (Pecora and Cooke, 1989; Cooke, 1989).
