I would like to know whether CO2 as gaseous phase not supercritical phase has been used to enhance oil recovery. If so could you please refer me to the reference?
Series of studies and field applications have been conducted using gaseous carbon dioxide not only for EOR purposes but also for carbon capture and storage purposes. Find attached, some of the papers on gaseous carbon dioxide for EOR.
Using CO2 as an Injectant for EOR project is not a question of supercritical or not but if the reservoir is deep the critical pressure of the CO2 is easily reached.
At low pressure you can look at application in Coal bed Methane application where CO2 is used to desorb the Methane .
I'm sorry, but this article is not translated into English. There are other articles on this topic, but they contain less information about oil production