TL;DR
I think Fulgora's oil collection/processing, as it stands, is far too simple and makes little thematical sense.What ?
Think about it:
How in the world are you getting clean, pre-refined petroleum products of any kind from this centuries-old polluted, sandy sludge?
That's where my idea comes in: Tar. Another new resource, exclusive to Fulgora. Too viscous & sticky to flow through regular pumps/pipes, it must be harvested via a new, modified offshore pump-type building(think something like the "Mud Collector" , or whatever it was called, from Seablock

Within this new building Tar is collected & also combined with Barrels (Yes, I want this process to require barrels. Sue me!) to create Tar Barrels, which are then unloaded & transported throughout the player's factory, in the same way as other raw materials like Scrap or Ore.
From there, the idea is mostly ambiguous; You'd probably then take the Tar Barrels to an Oil Refinery building to be separated into various oil products, along with a couple of wildcard waste/byproduct materials like Stone or Ice(maybe even a bit of Holmium ore, too?), and of course, the Barrels to be returned & reused. (Or recycled back into steel, if that's your preferred style

One thing is certain, though: This whole idea revolves around the basic concept of Tar being the fluid-focused analog to Scrap; A new resource harvested in a familiar way, but refined in a new, top-down focused manner instead.