Insomniac,
you are in Malaysia...that's a good start, and if it's sealed, that's perfect.
Give it a decent shake, and good to go.
mjoeking is pretty close to right...warm and sealed, out of the sun, and near forever would be fine.
If the oil was in a shed exposed to -25 to -30C, there's a chance that it could form gel like structures...need to be reheated to near boiling to break them.
as per demarpaint...Blackstone took some ancient oils (20W20 dino) put one in a paint shaker and the other just opened and sampled, and no measurable difference.