By Production:

* Oil: The United States currently leads in oil production, followed by Saudi Arabia, Russia, and Canada.

* Natural Gas: The United States also leads in natural gas production, followed by Russia and Iran.

By Proven Reserves:

* Oil: Venezuela holds the largest proven oil reserves, followed by Saudi Arabia, Canada, and Iran.

* Natural Gas: Russia has the largest proven natural gas reserves, followed by Iran, Qatar, and the United States.

Important Notes:

* Production: This refers to the amount of oil and natural gas extracted and processed in a given year. It can fluctuate significantly depending on factors like technological advancements, economic conditions, and geopolitical events.

* Proven Reserves: This refers to the estimated amount of oil and natural gas that can be extracted with current technology and at current prices. These estimates can change over time.

It's important to keep in mind that these rankings can change. The global energy landscape is constantly evolving due to technological advancements, economic factors, and political shifts.