I the US very few other f the shops are union, that said, I do agree that fairness and not favoritism should be applied when offering OT.
That even goes for day shift versus night shift should get a fair balance of OT.
But, if you’re looking to make a good living and a good outlook for your future, NOV is not the place to be.
They like younger, lower paid workers, especially temps, to keep cost low and quality lower.
Same for staff engineers and such, and it shows!