Working out there for a couple weeks changes everything when you've got your own transportation instead of being tied to someone else's schedule, you can actually live your life instead of just clocking in and out. Having your own wheels means you can explore the city on your own time, grab dinner wherever you want, and not feel like you're on some corporate leash the whole time. You can check out the car rental selection in Kazakhstan here
https://getrentacar.com/en-US/kazakhstan . You'll find a bunch of different options listed there, and you can compare prices and vehicle types without dealing with corporate rental desk people who don't really care about your situation. Just book something simple that'll handle the drive out to the refinery, and you're set for your whole stay.