IEA, Oil Market Report: World Oil Supply

On the whole growing tendency of world oil supply is observed in spite of the oil price collapse in 2014. However, this year’s oil supply prospects became less optimistic. Drop in the number of rigs drilling for oil and huge reductions in exploration and production capital expenditures have been reported as a result of current oil prices. This will certainly lead to a loss of production, particularly in the short- to medium-term, despite the fact that lower oil prices have forced operators to become more efficient as they aim to secure the benefits of cost deflation. Moreover, there are economic factors that also weighed heavily on the oil market: slowing global economic growth as the after-effects from the recent financial crisis.

According to current estimates, over the past 10 years around 40% of the world's oil supply are provided by OPEC member countries, the remaining part is procured by Non-OPEC countries. Both groups of oil producers show overall positive trend. OPEC Member Countries have made significant additions to their oil reserves in recent years, for example, by adopting best practices in the industry, realizing intensive explorations and enhanced recoveries. As a result, OPEC's proven oil reserves currently rise.