Life has been pretty good for refiners for the past five years, especially those with refineries in the middle of the country that have been able to take advantage of the shale boom such as HollyFrontier (NYSE:HFC), Northern Tier Energy (UNKNOWN:NTI.DL), and CVR Refining (NYSE:CVRR). Their success over the past few years has been predicated on their ability to source cheap crude thanks to inefficiencies in our oil transportation infrastructure. Without adequate takeaway capacity, the domestic crude benchmark -- West Texas Intermediate -- and the Canadian crude benchmark -- Western Canadian Select -- have both been priced at significant discount to the international standard: Brent. 

But this advantage has been slowly whittling away, and this quarter could be a little less promising than previous ones. Find out how these crude benchmarks have changed and why this could impact refiners earnings by tuning into the video below.