The Unayzah Reservoir (Permo-Carboniferous And Permian) Of Saudi Arabia, A Typical Example For A Large-Scale Reservoir Heterogeneity

In 1987, exploration started in Central Saudi Arabia shortly after the government directive enlarged Saudi Aramco's exploration activities outside the Retained Areas in Eastern Saudi Arabia. In June 1989, the first oil (Arabian superlight), condensate and gas discovery were made in the continental red bed sandstones of the Early- Middle Permian (Kungurian to Wordian from 275.6 to Ma 265.8 Ma) Unayzah Formation at the Hawtah Field, south of Riyadh. The Hawtah discovery provided a clear evidence for a significant hydrocarbon potential in the Paleozoic successions. Since then, Saudi Aramco has made several new oil and gas discoveries in the Khuff carbonates, Unayzah and Jauf sandstones, both in central and eastern Arabia. Intensive drilling that resulted from these discoveries has provided an immense wealth of new subsurface lithological and palynological data to establish the stratigraphy and sedimentology of the entire Paleozoic succession.