The Organization of the Petroleum Exporting Countries
OPEC is an intergovernmental bloc of major oil-exporting countries that coordinates production policy to influence global crude prices. This reference lists each member with the year it joined, its approximate production in million barrels per day, and its proven reserves, with sorting to compare them.
What this reference is for
Energy analysts, students, journalists, and policy researchers reach for an OPEC member list when they need a quick cross-country comparison — who pumps the most, who holds the largest reserves, and when each country joined the bloc. This page keeps those data points in one sortable table so you can compare members without jumping between multiple sources.
How it works
Each member carries an accession year — 1960 for the five founders who met in Baghdad — plus approximate crude production in million barrels per day (mb/d) and proven reserves in billion barrels. Sorting reorders the table by production or reserves. Figures are approximate and move with quota decisions, new discoveries and market conditions.
Key things to understand about the data
Production figures reflect quota allocations and actual output at a point in time, both of which fluctuate. When OPEC+ (the broader alliance including Russia and allies) agrees to cut or raise output, each member’s production figure shifts, sometimes substantially within a single quarter.
Proven reserves are geological estimates, not extraction guarantees. Venezuela tops the bloc’s reserve league table, but a large share is heavy extra-heavy crude that requires more energy-intensive upgrading and therefore has a higher breakeven cost.
Saudi Arabia’s special role: Saudi Arabia is by far the largest daily producer and the de facto swing producer. It periodically makes unilateral output adjustments to balance the market when member coordination is slow — a role that gives it outsized influence over the global oil price.
Membership is not permanent
Countries join, leave or suspend participation. The current roster of 12 members reflects departures as well as accessions: Qatar left in 2019, and Ecuador and Angola have at various points exited. The table reflects the membership composition at the time the data was compiled — confirm current status with OPEC’s official website for decisions after the publication date.
Practical use cases
- Quickly identifying which OPEC member holds the largest reserves when assessing long-run supply capacity.
- Comparing when founding members (1960) joined versus later entrants from sub-Saharan Africa.
- Checking approximate production shares for a country-risk or commodity analysis.
- Teaching: sorting by production versus reserves illustrates the mismatch between who pumps the most today and who holds the most oil in the ground.