According to recent estimates from the US Energy Information Administration, members of the Organization of the Petroleum Exporting Countries, excluding Iran, earned about $826 billion in net oil export revenues in 2013, a 7% decrease from 2012 earnings. But this was still the second-largest earnings totals during 1975-2013—the timespan of how long EIA has tracked OPEC oil revenues.
For each country, EIA derived net oil exports based on its oil production and consumption estimates from the latest edition of the EIA’s Short-Term Energy Outlook. For countries that export several different crude varieties, EIA assumes that the proportion of total net oil exports represented by each variety is equal to the proportion of the total domestic production represented by that variety.
These net export earnings do not include Iran's revenues. As explained by EIA, this is because of the difficulties associated with estimating Iran’s earnings, including the country’s inability to receive payments and possible price discounts Iran offers its existing customers.
According to EIA, a drop in OPEC oil production in 2013, largely because of the supply disruption in Libya, and a 3% decline in average crude oil prices as measured by the Brent crude oil price marker have led to the decline in OPEC earnings.
Saudi Arabia earned the largest share of these earnings, $274 billion in 2013, representing about one third of total OPEC oil revenues. On a per capita basis, OPEC (excluding Iran) net oil export earnings reached about $2,520 in 2013.
Based on projections from EIA's July 2014 STEO, EIA estimates that OPEC (excluding Iran) could earn about $774 billion in net oil export revenues in 2014 and $723 billion in 2015 (unadjusted for inflation). These declines from the 2013 level reflect projected declines in the call on OPEC crude oil production because of the large increases in non-OPEC production for 2014-15, as well as expected crude oil price declines that are also the result of declines in the call on OPEC crude oil production.