Is there any way to dissolve barium scale? I know that acids don't dissolve it and if it is encountered in a well that it is typically milled out, but is there any other way to remove it from a wellbore without milling?
We use basol- some kind of dissolver/ chelating agent to treat barium scale in our wells. Speak to a specialist chemicals company: (our chemical specialist is Roemex), and they'll help you out.
The problem with barium scale that doesn't make it soluble in water though is that it reacts with different types of formation fluids to form barium sulfate or the like.
After speaking to some chemical guys, we've found that pre-treating the produced water in the well is the best way to keep barium scale out of a wellbore, that doesn't mean that it will keep it out altogether, but it at least it inhibits a build up of scale that must be milled out.