Pipeline certified welders and high pressure and high temperature hydrogen line and vessel welders are akin like a shetland pony to a draft horse.
Mexico is trying desperately to avoid constructing pipelines because of billons of pesos in theft from tapped lines. The Queretaro refinery is the one Pemex is counting on to supply ULSD to Mexico City. Problem is, it is many hundreds of miles from the nearest port.
Which leaves the issue of how to transport vessels weighing hundreds of tons.
The Japanese are adept at this technology. But ferrying equipment and a thousand tons of nickel manganese steel plus a couple hundred engineers and workers across the Pacific would be an odyssey in itself.
Almost all Mexican refineries are old. Old enough to have used USA steel and welders and engineering. Japanese refineries use metric everything.
The delay in getting UBA product online is monumental. The Salina Cruz Oaxaca refinacion is already producing UBA premium gasoline but on a very limited startup basis. Salina Cruz, is a major sea port.
And to top it all Mexico gobernacion has been threatening Pemex because until UBA is available the city and state refuses to buy new buses and transport diesel vehicles.
What a freakin' mess!