Fahud is PDO's oldest and largest field in northern Oman. The Fahud structure was first recognized from the air in 1948 but it was only visited on the ground in 1954, when five geologists started field mapping and stratigraphic investigation work in the area. It was described by F. E. Wellings, chief geologist of IPC (Iraq Petroleum Company), as “a beautiful anticline—an absolute natural, which would have been drilled sooner if one could only get to it.” The first well, Fahud-1, was spudded on 18 January 1956 and abandoned 18 months later with only minor oil shows. Its prime target was the Jurassic Arab zone. But because Fahud-1 was dry, neighboring anticlines were avoided. In the period 1957–1960, three further unsuccessful deep exploration wells were drilled at Ghaba, Haima, and Afar. In 1963 the Fahud-2, 1.5 km from the Fahud-1, hit a pay zone. The field is roughly 17 km long by 2.5 km wide, with an estimated 6 billion-plus barrels of oil, making it the largest field in Oman. It is producing from the Natih fractured carbonates. Following the discovery of the prolific Fahud and Natih fields, facilities and a pipeline were built and oil exports began in 1967. To date, there are more than 400 wells drilled in this field.