https://www.nytimes.com/2021/03/27/world/middleeast/china-iran-deal.html
China, With $400 Billion Iran Deal, Could Deepen Influence in Mideast
The countries signed a sweeping pact on Saturday that calls for heavy Chinese investments in Iran over 25 years in exchange for oil — a step that could ease Iran’s international isolation.
bzw
https://pemedianetwork.com/petroleum-economist/articles/corporate-finance/2017/the-puzzling-glencore-qatari-rosneft-deal