The proven oil reserves in Saudi Arabia are the second largest in the world, estimated to be 268 billion barrels (43×10 9 m3) (Gbbl hereafter), including 2.5 Gbbl in the Saudi–Kuwaiti neutral zone. They are predominantly found in the Eastern Province. These reserves were the largest in the world until Venezuela announced they had increased their proven reserves to 297 Gbbl in January 2011. The Saudi reserves are about one-fifth of the world's total conventional oil reserves, a large fraction of these reserves comes from a small number of very large oil fields, and past production amounts to 40% of the stated reserves.
In 2000, the US Geological Survey estimated that remaining undiscovered oil reserves in Saudi Arabia had a probability-weighted average of 90 Gbbl.
Saudi Arabia has traditionally been regarded as the world’s most important swing producer of oil. When acting as such, the Saudi government would increase or decrease oil production to maintain a more stable price.
Saudi Arabia produced 10.3 million barrels per day (1.6×10 6 m3/d) (Mbbl/d) in 1980, 10.6 Mbbl/d in 2006, and in the region of 9.2 Mbbl/d in 2008. Saudi Arabia maintains the world’s largest crude oil production capacity, estimated to be approx. 11 Mbbl/d at mid-year 2008 and announced plans to increase this capacity to 12.5 Mbbl/d by 2009 Cumulative production through the end of 2009 was 119.4 billion bbl. Using the stated number of 267 Gbbl, past production amounts to 40% of the stated remaining proved reserves.
After the then U.S. president George W. Bush asked the Saudis to raise production on a visit to Saudi Arabia in January 2008 and they declined, Bush questioned whether they had the ability to raise production any more. In the summer of 2008, Saudi Arabia announced an increase in planned production of 500,000 barrels per day. However, in 2008, some experts believed that Saudi oil production had already peaked or would do so in the near future. In April 2015, the Saudi oil minister Ali Al-Naimi said that Saudi Arabia produced 10.3 million barrels per day in March that year, which was the highest figure based on records since the early 1980s. The previous peak was in August 2013 at 10.2 million barrels per day.