I've been playing with your mod in my current game for quite a while now and I like the progression so far. Something that sticks out are the vanilla refinery and centrifuge, since their crafting speed of 1 is lacking compared to the upgraded "fabricators" from your mod. What are your thoughts about implementing upgraded versions of these two buildings?

I agree, there should be better versions of those buildings.
Adding two new tiers of Oil-refinery, centrifuge, and also pumpjack

"I came looking for copper and I found gold!" ;)
Few grains of salt though:
- One new research is titled: unknown key: "technology-name.advanced-oil-machinery"
- The crafting speed, pollution, and/or power usage of the new buildings seem off (at least in the tooltip research preview):
-- Power usage, pollution: Centrifuge 2 and Oil Refinery 2
-- All three: Centrifuge 3, Oil Refinery 3, Pump Jack 2 and 3
- Deconstructing the Oil Refinery 2 returns a regular Oil Refinery to the inventory.
- Eventhough I have "Chemical Plant MKII" researched I can't construct the Centrifuge 2.

A bit quick on the copy/pasting it seems.
Edited the power/pollution/speed of the new machines.
As for the missing recipe, that's a limitation of Factorio.
Use the commandline interface to enable the recipe with:
/c game.player.force.recipes["centrifuge-2"].enabled=true

Also, thanks for the feedback. It's much appreciated.