"The two countries have also made joint investments in various liquefied natural gas and natural gas projects."

https://www.scmp.com/economy/china-economy/article/3013528/russia-keen-sell-yuan-bonds-deepen-ties-china-and-further

China Economy

Russia keen to sell yuan bonds to deepen ties with China and further reduce US dollar dependence

• China and Russia seek to further strengthen ties amid escalating tensions with the United States after Xi Jinping and Vladimir Putin upgrade relationship this week
• At St Petersburg International Economics Forum, Russian bank claims there would be strong demand for yuan bonds

Additional government-led borrowing is necessary to raise money to fund large energy projects that would be mutually beneficial, he noted while speaking during a panel discussion at the St Petersburg International Economics Forum on Thursday.

China is Russia’s largest trading partner, while Russia is China’s largest crude oil supplier. The two countries have also made joint investments in various liquefied natural gas and natural gas projects,but most of these are financed by the equity market and state subsidies, Shulakov said.