Under the current petrodollar structure, global oil sales are made in US dollars. All countries which import oil must first buy the US dollar before they can buy oil (this creates an artificial market for the dollar). China will soon be able to bypass this and buy its oil using it's own currency yuan which is just another fiat currency but it will give the option for countries to convert yuan into physical gold.
The US won't go down without a fight. We all know what happened to countries that have challenged the petrodollar system. Before Saddam Hussein was overthrown, Iraq were selling their oil for Euros and was changed back to the dollar once the country collapsed. Qaddafi had plans to establish a pan-African currency backed by gold which Libya and other African countries intended to trade oil in. https://wikileaks.org/clinton-emails/emailid/6528
Being the worlds largest oil importer, China will use this leverage plus the added incentive of gold to make countries abandon the US dollar.
The dollar being used as a political weapon is coming to end. Americas collapse is imminent. I advice you guys to start investing in physical gold while it is still cheap.