It’s true that the infrastructure is already in place but it is important to understand that it is not simple infrastructure, and with a few exceptions, it is already pretty much fully utilized by Canadian and Mexican heavy crude/bitumen so it’s not like they can just double their capacity and start processing Venezuela too. You’re right about giving an opening to pressure Canada/Mexico though.

But it’s questionable if there’s really much upside for the US on the financial side. The opportunity to pressure is definitely there, but more pressure isn’t going to get blood out of a stone. Venezuelan oil will still have costs associated with it, and Canadian and Mexican oil is already really cheap.

The oil itself may be essentially free the way they’re stealing it with military force, but It’s not going to be cheap to build up Venezuela’s production infrastructure and it’s not going to be cheap to transport the oil stateside, and both Mexico and Canada already have all that infrastructure in place too, and already give a huge discount to the US since they have nowhere else to affordably sell or refine their oil as they have effectively no indigenous refining capacity for heavy crude and few other export options. During a few of the oil price plummets around Covid, Canadian oil (Western Canadian Select) was actually selling for negative prices, Canada was paying the US to take it off their hands and refine it for them. With global oil prices already trending relatively low, it’s going to be hard for oil from Venezuela to realistically compete with situations like that.

The most believable explanation that I’ve heard is that this is not really about directly stealing Venezuela’s oil reserves as much as it is about denying it to Russia and China, and maybe securing them in case of some future conflict. And that, I think, makes an awful lot of sense geopolitically as distasteful as I personally find the whole affair.