Do you think travel restrictions would be of any importance to the oil import?
Just a layman’s opinion but ...
Since a ship travels more slowly than a plane, symptoms would manifest long before a tanker reaches the US. If someone legislates in a knee-jerk fashion it could be bungled, but surely we could work something out with sea trade.
But there is the political consideration. This does give Liberia ‘polical pull’. Freighters and oil tankers choose flags based on the tax burden. I don’t know how long it would take to change their national status, but a transition period could temporarily hurt oil prices I would guess.
There would likely be significant economic impact on those nations suffering from ebola outbreaks, as ships which had been in those ports might not be allowed in ports elsewhere until the outbreak has burned out. That would amount to a trade moratorium, unless they first shipped cargoes by land or sea to other ports fro transshipment.
I am not sure how well that would play out.