I'm sure all oil companies upgrade all the time.....but single companies market - not set universal standards. Hence the I don't know if 'Group II+' is an 'official' thing - so to speak.
A plant shut down will have minor upgrades of the same type of process line … but mostly major PM's and certification of like for like components. Valves, piping, PRV's, rotating equipment, GTG or mechanical drives (turbine) would be good examples