Because there is so much excess capacity in the worlds refineries, because there is a fair range of capabilities in that excess capacity and because if there was not enough refining capacity to handle all the sour crude that is available, the price of sour crude would be selling at a greater discount to sweet crude than the current modest discount.

FORBES: Why I think Saudi Oil Production is now at Capacity

It supports my technical view that the current decline in crude oil should be a buying opportunity.

FORBES: Profit from Oil's Seasonal Low

This current chart compares the October crude oil futures with the Spyder Trust ( SPY).

FORBES: Get an S&P Edge from Crude Oil