12 month broker analyst forcast buy-outperform, page-15

Drown in heavy sour yes so Mexico, Iran, Venezuala, over half of Saudi output, most of Iraq, most of Canada etc etc are heavy sour and can only be processed at certain refineries to remove the heavy sulphurs - the world is not drowning in oversupply of light sweet. I have no idea why light sweet & heavy sour somehow get overlapped when they are quite different in both supply and quality and thus price.
Even at Cushing in the US a big % of whats stored has come down from Canada which has 3 pipelines running straight to Cushing.

Heavy produces over 28% of residuals (asphalt/roofing tar) which has to be refined even further to try and get more higher value product and so many refineries aren't set up to process it.
Light produces only around 5% residuals after initial refining the rest is higher grade hydrocarbons like petroleum etc.