Venezuela has long been one of the most important sources. Valero has historically been one of the largest U.S. refiners of Venezuelan heavy sour crude, and those barrels have again become an important part of Valero’s heavy crude feedstock in recent years. That is probably the closest thing to a primary source for Port Arthur. Recently, Venezuelan crude is again becoming a large share of the heavy crude diet for Valero refineries.
Canadian crude is another major source. Heavy Canadian oil sands blends are well suited to a refinery like Port Arthur because it has the cokers and other upgrading units needed to process dense, sulfur-rich crude economically.
Mexican Maya crude is a classic Gulf Coast heavy sour crude and has long been a standard feedstock for refineries in that region.
Middle Eastern heavy sour crude, including Saudi barrels, has also been part of the mix at times, although that is generally more opportunistic and depends on pricing, logistics, and market conditions.
Port Arthur is configured to process discounted heavy sour crude from multiple places. It can receive crude by ship, barge, pipeline, and rail, so Valero can shift among sources depending on sanctions, transport economics, and heavy-versus-light crude price spreads.
We know there are enemies of the US in Venezuela, Mexico, the Middle East and Canada, so take your pick!
Thanks.