Pros
There are a lot of resources to learn and expand your toolset. Great work-life balance and 9/80 schedule. Compensation for extra hours worked, even as a salaried employee Lots of great benefits like 401K match, paternity/maternity leave, bonuses, Refining is by far one of the most complex manufacturing processes, and it's fun to learn from a purely engineering perspective
Cons
They pay you the same no matter where you work in the US. Terrible for California, great for middle of nowhere Mississippi. Middle management is generally out of touch with how the world has changed and do a bad job of aligning incentives and good work. Career progression is slow, stable, and steady, like it's the 1950s or something. Doesnt feel like good performance is rewarded. Everyone is just collecting a paycheck. There is no passion for what you do (I mean, it is oil and gas). It feels like the older managers and generation are just trying to get to retirement. There's not much for people less than 10 years experience. Attrition is horrible. Local culture is a good old boys club.