Challenges to the Upstream Development Program
One challenge the Saudis face in achieving their strategic vision to add production capacity is that their existing fields experience 6 to 8 percent annual "decline rates” on average (as reported by Platts Oilgram in 2006) in existing fields, meaning that the country needs around 700,000 bbl/d in additional capacity each year just to compensate for natural decline.
Decline estimates for Saudi Arabia vary widely, however.
The Ministry of Petroleum maintains that decline rates in Saudi Arabia are around 2 percent annually. Saudi Aramco has stated that it will also conduct additional drilling at existing fields in order to help compensate for the natural declines from the mature fields.
[the EIA is being diplomatic here, IMO. Most outside experts think the Saudis are full of when they put out "pie in the sky" estimates of their own capacity--RG]
Saudi Aramco, Saudi Arabia’s national oil company, estimates that the average total depletion for Saudi oil fields is 29 percent, with Abqaiq (the oldest) 74 percent depleted, the giant Ghawar field having produced 48 percent of its proven reserves and the younger Shaybah, just 5 percent depleted. Aramco also reports that Saudi oil reserves are likely underestimated, not overestimated, although some analysts have disputed Aramco's optimistic assessments of Saudi oil reserves and future production. Minister Al-Naimi has refuted these contrarian arguments, and stated that Saudi Arabia could add as much as 200 billion barrels of oil to proven reserves after an extended period of investment and exploration.