RE:The reasons I bought CJ over BNEJust a note blueoiler: Light crude has a LOWER viscosity not higher (as you stated). Think molasses. High viscosity = very viscous = very thick = higher density = lower API gravity.
Light crude (+30' API) is NOT stacking up in refineries as per previous fake news. Check out the Oil & Gas Journal archives for correct info. Mexican Maya (20' API) is priced at an $8 discount to WTI (39.5' API) which tells you that the refineries achieve a higher crack spread with low viscosity crude. The future price upside is greater for heavy crude as the Gulf Coast refineries are built for average 30' API oil.
Also, the vast majority of crude oil exports from the USA are light oil and there is a major shortage of light oil in the far east (China) refineries. I agree, that with heavy crude production declining rapidly in Venezuela (and Mexico) the WCS/WTI differential will narrow even more than what we have seen recently. The rails are a problem but Enbridge and TransCanada are improving efficiencies by removing the "air gap" of nominated but not delivered volumes.
I'm buying more CJ.