Geez,
You seem to be getting upset that people ask questions. A few posts ago you showed a website with a news item that indicated no money is being spent on maintaining refineries. I just wonder about the other articles I read that say money is being spent.
I have no idea how Gulf will deal with getting fuel in Mexico. In the US there are refineries all over the place that sell to many different fuel supply companies - gas stations. In Colorado there is one big refinery in Denver (Suncor) and there must be 20 or more "gas station" companies buying their fuel from that refinery - sold under many names all over the state of Colorado. All the gasoline and diesel in Colorado pretty much comes from that one refinery no matter whose name is on the sign over the gas station. Some states in the US have many refineries and other states have none at all. One of the most populace states would be NY and there are no refineries - but there are several refineries in NJ. Arizona has no refineries.
To the best of my knowledge Gulf does not own even one refinery these days. They may not even produce any oil. The old Gulf Oil (Mellon Family) no longer exists but a long involved explanation says it is a name owned by someone - now operating about 2,000 stations in the US. The old Gulf was absorbed by Standard of California - now Chevron I think. So in Mexico my guess would be they will be buying from Pemex - or whoever else might set up a refinery and sell fuel in Mexico. I seriously doubt any company could profitably haul fuel in tankers all the way from the US to Mexico City. Gulf is buying Pemex stations and putting their sign up and probably buying fuel from Pemex - I have no idea why they would do this. They do not need infrastructure. They own very little in the US and have very few employees - they have intellectual property rights to a name - a name that was once one of the world's largest companies but has not been for many years. Why they want a presence in Mexico I have no idea.
Here is a Wiki listing of the largest oil refining companies in the US and the states where they operate. Also shown are some of the largest refineries. Companies few people ever heard of own huge refining companies. Company names everyone knows own no refineries.
https://en.wikipedia.org/wiki/Petroleum_refining_in_the_United_States
Here is a Wiki list of the world's refineries. Some ways down the list is the US and the refineries in each state. They also list the refineries in Mexico.
https://en.wikipedia.org/wiki/List_of_oil_refineries
Mexico
Tula Refinery (Pemex) Tula, Hidalgo 300,000 bbl/d (48,000 m3/d)
Minatitlan Refinery (Pemex) Minatitlan, Vera Cruz 167,000 bbl/d (26,600 m3/d)
Cadereyta Refinery (Pemex) Cadereyta Jiménez, Nuevo León 217,000 bbl/d (34,500 m3/d)
Salamanca Refinery (Pemex) Salamanca, Guanajuato 192,000 bbl/d (30,500 m3/d)
Ciudad Madero Refinery (Pemex) Ciudad Madero, Tamaulipas 152,000 bbl/d (24,200 m3/d)
Salina Cruz Refinery (Pemex) Salina Cruz, Oaxaca 227,000 bbl/d (36,100 m3/d)