The Organization of the Petroleum Exporting Countries — better known as OPEC — is the most powerful cartel in global energy markets. Founded in 1960, it coordinates oil production among 13 member nations to influence crude oil prices worldwide.

If you’ve ever watched oil prices spike after a single meeting in Vienna, that’s OPEC at work. Understanding how this organization operates is essential for anyone tracking energy markets, Middle East economies, or global geopolitics.

This guide explains who OPEC’s members are, how the organization sets production quotas, what OPEC+ means, and why its decisions send shockwaves through financial markets from Riyadh’s Tadawul exchange to Wall Street.

Who Are OPEC’s Members?

OPEC currently has 13 member countries, most of them in the Middle East and Africa:

Five of the founding members are Middle Eastern countries, which explains why OPEC’s decisions are inseparable from Middle East geopolitics.

Saudi Arabia is by far the largest OPEC producer and holds the most spare capacity — the ability to increase or decrease production quickly. This gives the Kingdom outsized influence over OPEC decisions, a role that directly connects to the Saudi Arabia economy and its national budget.

Former Members

Qatar left OPEC in 2019 to focus on its liquefied natural gas (LNG) strategy. Ecuador and Indonesia also departed in recent years. Membership is voluntary, and countries occasionally leave when OPEC quotas conflict with their production goals.

How Does OPEC Control Oil Prices?

OPEC doesn’t set oil prices directly. Instead, it controls supply — and supply is one half of the price equation.

Here’s the mechanism:

1. Production Quotas

OPEC members agree on how many barrels per day each country will produce. When OPEC cuts production, less oil reaches the market, prices rise. When OPEC increases production, more oil is available, prices fall.

2. Ministerial Meetings

OPEC’s Joint Ministerial Monitoring Committee (JMMC) meets regularly — typically every month — to review market conditions. Full ministerial conferences happen twice a year, though emergency meetings can be called when markets are volatile.

These meetings in Vienna (OPEC’s headquarters) are among the most closely watched events in global finance. A single statement from Saudi Energy Minister Prince Abdulaziz bin Salman can move oil prices by several dollars per barrel within hours.

3. Spare Capacity

Saudi Arabia maintains roughly 1.5–2 million barrels per day of spare production capacity. This is OPEC’s “emergency lever.” If prices spike too high (which can trigger recessions and destroy demand), Saudi Arabia can ramp up quickly. If prices crash, they can cut deeper than anyone else.

No other OPEC member has this flexibility, which is why Saudi Arabia is often called the “central bank of oil.”

What Is OPEC+?

In 2016, OPEC formed an alliance with 10 non-OPEC oil producers to coordinate production more broadly. This expanded group is called OPEC+ (or OPEC Plus).

OPEC+ Non-OPEC Members

• Russia (the most significant partner)
• Mexico
• Kazakhstan
• Oman
• Azerbaijan
• Bahrain
• Brunei
• Malaysia
• South Sudan
• Sudan

Together, OPEC+ controls approximately 55% of global oil production and holds over 80% of proven reserves.

The OPEC+ alliance was formed to address the rise of US shale oil, which had disrupted OPEC’s traditional market control. By bringing Russia and other producers into coordinated cuts, OPEC+ significantly expanded its ability to influence prices.

How OPEC and OPEC+ Differ

The Saudi-Russia dynamic within OPEC+ is critical. When the two agree, markets tend to stabilize. When they disagree — as in the 2020 price war — oil prices can collapse. That episode saw Brent crude briefly fall below $20 per barrel.

A Brief History of OPEC

1960: Founding

OPEC was founded on September 14, 1960, in Baghdad, Iraq. The five founding members — Saudi Arabia, Iran, Iraq, Kuwait, and Venezuela — created the organization to resist unilateral price cuts by Western oil companies that dominated production at the time.

1973: The Oil Embargo

OPEC’s most consequential moment came during the 1973 Arab-Israeli War. Arab OPEC members imposed an oil embargo on nations supporting Israel, quadrupling oil prices almost overnight. The embargo demonstrated that OPEC could weaponize energy supply as a geopolitical tool.

1980s: Price Crash and Internal Tensions

Overproduction by some members and the rise of non-OPEC producers (like North Sea oil) caused prices to crash in the mid-1980s. Saudi Arabia briefly abandoned its swing producer role, flooding the market to punish overproducers. The result was a prolonged price slump that damaged all member economies.

2014–2016: Shale Revolution

The US shale boom fundamentally challenged OPEC’s market power. US production surged from 5 million bpd to over 12 million bpd within a decade, making America the world’s largest oil producer. OPEC initially tried to out-produce shale, but eventually pivoted to the OPEC+ alliance for broader supply coordination.

2020: Pandemic and Price War

COVID-19 destroyed oil demand while Saudi Arabia and Russia briefly engaged in a price war. The result: oil futures briefly went negative for the first time in history. OPEC+ responded with the largest production cuts ever agreed — nearly 10 million bpd — stabilizing markets.

2022–2026: Managed Transition

The current era balances tight supply management with growing awareness that the world is transitioning toward cleaner energy. OPEC+ has maintained a cautious approach to production increases, keeping prices in a range that funds economic diversification programs across the Gulf while not pushing prices so high that they accelerate the adoption of electric vehicles and renewable energy.

How OPEC Decisions Affect You

OPEC’s production decisions ripple far beyond oil trading desks:

Gasoline prices: When OPEC cuts production, crude oil prices rise, and pump prices follow within weeks. Consumers in importing countries feel this directly.

Gulf economies: Oil revenue still accounts for 50–70% of government income in most GCC countries. OPEC’s ability to maintain prices above $70–80 per barrel is what funds everything from Saudi megaprojects to UAE infrastructure.

Stock markets: OPEC decisions move energy stocks, airline stocks, petrochemical companies, and currency markets simultaneously. The Saudi stock market (TASI) and other Gulf exchanges often react within minutes of OPEC announcements.

Inflation: Higher oil prices feed directly into transportation and manufacturing costs, contributing to inflation globally.

Geopolitics: OPEC membership gives oil-producing nations diplomatic leverage. Saudi Arabia’s central role in OPEC is a key source of its geopolitical influence.

OPEC’s Challenges in 2026

The Energy Transition

Electric vehicle adoption is accelerating, renewable energy costs are falling, and major economies have net-zero commitments. OPEC faces the long-term risk of declining demand. The organization publicly pushes back against “peak oil demand” narratives, but member states are quietly investing billions in diversification — Saudi Arabia’s $50 billion renewable energy program and the UAE’s Barakah nuclear plant are examples.

Internal Compliance

Not every member follows its quota. Some countries, particularly those with weaker economies, often produce above their agreed limits. Monitoring and enforcing compliance is a perennial challenge.

US Shale Flexibility

American shale producers can ramp up within months when prices rise, limiting how much OPEC+ can push prices up. This creates a “price ceiling” that OPEC must navigate carefully.

China’s Demand Trajectory

China is the world’s largest oil importer and its economic growth rate directly affects global demand. Any slowdown in Chinese demand reduces OPEC’s pricing power.

FAQ

How many countries are in OPEC?

OPEC currently has 13 member countries. The expanded OPEC+ alliance includes 23 countries total.

Where is OPEC headquartered?

OPEC’s headquarters is in Vienna, Austria. It moved there from Geneva, Switzerland, in 1965.

Does the US belong to OPEC?

No. The United States is the world’s largest oil producer but is not an OPEC or OPEC+ member. US production operates independently, driven by market forces rather than coordinated quotas.

What is the difference between OPEC and OPEC+?

OPEC is the original 13-member cartel. OPEC+ is the expanded alliance that includes OPEC plus 10 additional countries (most notably Russia) that coordinate production together.

Can OPEC control oil prices forever?

OPEC’s influence depends on its share of global production. As the world shifts toward renewable energy and electric vehicles, OPEC’s long-term power will diminish — but that transition will take decades. For now, OPEC+ remains the single most influential force in oil markets.

Why does Saudi Arabia have so much power in OPEC?

Saudi Arabia produces more oil than any other OPEC member and holds the most spare capacity. It can increase or decrease production faster than anyone else, giving it the ability to enforce discipline and steer OPEC decisions.

Key Takeaways

• OPEC is a 13-member oil cartel founded in 1960 that coordinates production to influence global oil prices
• Saudi Arabia is OPEC’s most powerful member, acting as the “swing producer”
• OPEC+ (formed 2016) adds 10 non-OPEC countries including Russia, controlling ~55% of world production
• OPEC decisions directly affect gasoline prices, stock markets, inflation, and Gulf economies
• The energy transition is OPEC’s biggest long-term challenge, but its influence remains dominant in 2026