POLLASTRO, RICHARD M., U.S. Geological Survey, Energy Resources Team, MS 939, Denver, Colorado 80225

Abstract: Application of the Total Petroleum System Concept to Assessing Undiscovered Gas Resources of the Ghaba and Fahud Salt Basin Provinces, North-Central Oman

The U.S Geological Survey, World Energy Project, ranked the Ghaba and Fahud Salt Basin Provinces of Oman as "priority" global geologic provinces on the basis of discovered petroleum volumes. The Total Petroleum System concept, modified from Magoon and Dow's Petroleum System, is used in conjunction with an assessment unit (a geologically defined, mapable volume of rock with similar exploration strategy and risk characteristics) to assess undiscovered oil and gas resources of the world.

The Ghaba and Fahud Salt Basin Provinces contain three Total Petroleum Systems (TPS) that each have one corresponding assessment unit. Hydrocarbons are generated from organic-rich source beds (Huqf and "Q") within the Infracambrian Huqf Supergroup and from organic-rich facies of the Cretaceous Natih Formation. Huqf rocks are the primary source of gas in these provinces; little gas has been generated from Natih sources. Although primarily oil provinces, gas and condensate are produced from both clastic and carbonate reservoirs that range from Cambrian to Cretaceous in age. Future significant gas-field growth and gas discoveries are anticipated, particularly in the Lower Paleozoic Haima clastics at depths of >5,000 m, with further potential for discoveries in underlying unproven Huqf reservoirs.

Two systems, designated as the North Oman Huqf -- Shu'aiba (!) TPS of the Fahud Salt Basin Province, and the North Oman Huqf/"Q" -- Haushi (!) TPS of the Ghaba Salt Basin Province, each comprise a multiple, structural-style assessment unit that includes deep Haima and Huqf prospects and is used to estimate sizes and numbers of undiscovered gas fields. 

AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England