China has a backdoor for oil from Russia and Iran (https://www.atlanticcouncil.org/blogs/new-atlanticist/the-axis-of-evasion-behind-chinas-oil-trade-with-iran-a

China has a backdoor for oil from Russia and Iran (https://www.atlanticcouncil.org/blogs/new-atlanticist/the-axis-of-evasion-behind-chinas-oil-trade-with-iran-and-russia/ https://www.atlanticcouncil.org/blogs/new-atlanticist/the-ax...) which is part of what feeds their massive reserves. Russia and Iran have an interest in continuing this trade since they're sanctioned by the US and most crude is priced in USD. It's not a major source of their oil due to threats of sanctions from the US, but in a pinch they can ramp it up if needed.