The Ghawar oil field extends from the eastern city of Al-Ahsa to near Al-Kharj (southeast of the capital, Riyadh), on an area of 256 km, in the largest oil field in the world, in terms of area, quantity of production and oil reserves, as its production reaches 5 million bpd.
Saudi Aramco, in its bond issuance circular, said that Ghawar, the world’s largest oil field, contained 58 billion barrels of oil equivalent in its combined reserves by the end of last year.
The numbers were not the only evidence on Ghawar’s size for many geologists working in the oil and water field, but the date of its inception is a blatant evidence as well.
Ghawar and Bedouins
Professor of Petroleum and Geology Abdul-Aziz bin Laboun, spoke about this oil field, saying: “Ghawar contains all different types of oil, it is 80 km away from the east coast. Excavation works first started in Ghawar in the Ain Dar region, and then Haradh oil field was discovered, as well as the Uthmaniyah field and then Shedgum”.
“I discussed the Bedouin knowledge of the details of the geographic location with Dr. Mohammad Jaber Al-Mahmoud, a senior pensioner of Saudi Aramco, who cut off the area when he was young with his father on camels. We also discussed how the Bedouin best know the descriptions of the well, especially such contours of the land except through aerial photographs and maps, however, the Bedouin sense and knowledge of the land them him discover quickly, and differentiate between the mountains, ravines, and valleys, so they were very helpful for Aramco’s geologists at the beginning of the exploration.” Laboun said.
History proves that nomads were very helpful for Saudi Aramco’s geologists, with the beginnings of the discovery of oil in Saudi Arabia, the distinctive mark in the history of Saudi oil is the famous Bedouin, “Khamis bin Ramthan”, who Aramco retains the credit for helping them to innate knowledge.
Ghawar began work in 1948, producing the first oil shipment in 1951, and 2005 is the peak of its production, and it is still considered the world’s largest oil field.
Geological and oil studies have proved that the giant well fold consists of 7 structural constructions, and that the oil discovered in these fields is only from a long field in a structural construction trap, representing a giant fold extending from the south to the north.
Laboun pointed out that the main oil reservoirs in general are in the limestone rocks of the late Jurassic period, deposited in shallow marine environments, whose geological life extends from about 155 to 145 million years ago, known as the formation of the Arab and Jibalah basins.
These two basins were the source of oil at the discovery of Ghawar. Oil was occupying an area of 875 cubic miles, and occupies a column length of 1300 feet and density between 36 degrees according to the American oil scale in the north of the field to 33 degrees in the south.
The production began in Ghawar in 1951 with a rate of 600,000 bpd, until it began to gradually increase to 5 million bpd.