SWhat can we learn from U.S. complex refiners?  Did they try to increase light crude oils to maximize light product production?  Did they seem constrained in their heavy-sour crude use?
	SThis chart explores one company’s crude oil shifts in 2004.  It illustrates the dynamics through 2004, showing how the system shifted to using heavier feedstocks as the incentive improved (i.e., the light-heavy price differential increased).  The data here are import volumes for one company that uses over 600 thousand barrels per day of crude oil in its refineries, each of which uses a wide range of crude oils.
	SAs crude prices increased, and as the prices for light sweet crude oil increased faster than heavier crude oils, this company shifted to running more of the heavier crude oils.
	SIn this case, the heavy sour crude oil refineries increased their use of heavy sour as well as medium sour, while backing down on medium and heavy sweet crude oils.  While this company’s refineries may have produced more residual fuel oil as a result, that loss in product value was apparently less than the savings on crude oil feedstock costs.
	SIn summary, this chart illustrates that:
		–The decision to use heavy sour crude oil is complex, with many crude-mix options  available for optimization.
		–This company was able to use more heavy sour crude oil, implying the conversion capacity “constraint” was not necessarily getting in the way.
		–The increases in heavy sour crude oil use followed increases in economic incentives to use more as the light-heavy price differential grew in the latter part of 2004.
	SThe next few slides will explore U.S. refinery behavior further in order to see if any effects of conversion capacity limitations can be detected.