Russia and China threaten Petro Dollar

Many argue that since the US dollar left the gold standard in 1971, the main factor keeping it alive as the world’s reserve currency despite all the printing and abuse since, is that all OPEC oil trades are settled in USD (“Petrodollars”).   Well last week Russia announced a $20b deal with Iran to trade their oil for goods.  There are rumours too that China is well advanced with a yuan (Renminbi) deal with Saudi Arabia (China upset at the US’s money printing, role in Syria and more recently Japanese territories, and Saudi’s upset at the US not supporting them on Syria).  China and Russia have reportedly already done a massive deal on natural gas supply in rubles.  Any coincidence Russia, Iran and China have been stocking up on gold?