As of January 1992, official proven crude reserves were estimated at 4.6 billion barrels, up almost 6 percent from 1991 and up 83 percent from the oil reserve estimate in 1980. The relatively gradual increments to Oman's reserve base since 1980 were attributable to the discovery of new, smaller oil fields and reviseÍÍÍÍd estimates for existing fields.

More than one-half of Oman's total reserves are concentrated in the northern region, where six fields--Jibal, Natih, Fuhud, Al Huwaysah, Al Khuwayr, and Shaybikah--are part of a single geological structure containing recoverable reserves of more than 2 billion barrels. Similarly, in the south, eight principal producing fields also come from a single geological structure.

Several foreign companies that are engaged in exploration and production activities, such as France's Elf Aquitaine Oman, the Occidental Petroleum Corporation (Occidental Oman), and the American Oil Company (Amoco), signed agreements in the 1970s. Others, such as the Japan Exploration Company (Japex Oman) and Canada's International Petroleum, followed in 1981 and 1984, respectively.

Data as of January 1993