That's kind of odd. I'm sure you've noticed that when you click on that well it says, "look out!" That's because the drakes are spawning. They are energy drakes and they spawn in 4 groups in the upper northwest part of the zone - sort of northeast of where the obelisk is up there. Are you sure it stopped working? I've just never heard of that before.
The 5k exp well, on the other hand, works sporadically but it can be re-used. I think it will only give you a certain amount of exp above your current level and there may also be limits on how often you can use it. I've found that the best thing to do is to train up completely before you try to use it. Then you get the maximum benefit.