Six wells, then a seventh
The oil concession was signed with Standard Oil Company of California on 29 May 1933, for sixty years, and geologists arrived that September. Drilling of Dammam Well No. 1 began on 30 April 1935, but none of the first six wells delivered: some ran dry, one brought up mostly water, another no more than 100 barrels a day.
Drilling on the deep test well, No. 7, began on 7 December 1936. Traces of oil showed in the drilling mud at 1,097 m in October 1937, and the well blew out on the last day of that year.
March 1938
At about 1,440 m, in the first week of March 1938, oil flowed. On 4 March the well gave 1,585 barrels a day, the date taken as the start of the Kingdom's oil era, and within weeks it passed 3,800. A 69 km pipeline then joined the field to Ras Tanura, where on 1 May 1939 King Abdulaziz opened the valve himself to load the first tanker.
The well produced 32,436,877 barrels before it was closed in 1982. In 2008 King Abdullah bin Abdulaziz named it the Prosperity Well, Bir al-Khair, and Ithra now stands beside it.