With a maxed intelligence and a buffed luck of 141, an enchant skill of 99
exquisite amulet and a azura star containing an ascended dreamer I am trying to make an amulet with a constant invisability affect, no charges. I have tried it 15 times and failed every time. Is it just a game no no or is it just such a slim chance of success?

Make many fortify intelligence potions. Drink fortify intelligence potions. Make a lot more while the effect of the old ones is still active. Drink them. Then try to do enchant. With a sufficiently high intelligence you'll be able to enchant more easily.

NB: this sort of info can be found with a search.

I was pretty sure your chance of success at enchanting wasn't affected by intelligence... maybe I was wrong though.

I'd suggest paying an NPC to do it