Is China's 1-butene market genuinely oversupplied, or is it just internal group transfers?

Is China's 1-butene market genuinely oversupplied, or is it just internal group transfers?
China's 1-butene supply growth has been driven almost entirely by new PE capacity, since co-monomer demand pulls the molecule into the market. Yet much of the apparent surplus is illusory. Of roughly 150,000 tonnes of merchant volume in 2020, Sinopec and PetroChina accounted for over 50,000 tonnes, and most of that moved through internal group transfers rather than open-market sales. Genuine market liquidity comes from joint ventures and private producers such as Sinopec SABIC Tianjin, CNOOC and Shell, Fujian Refining and Sinopec-SK. Imports, absent before 2018, reached 36,000 tonnes by 2020, mainly from South Korea and Qatar. So the surplus narrative reflects logistics, not true excess supply.