The stuff wants to get out. Wouldn't it just pop out somewhere else?
Well, not really. The pressurized zone where this was coming from was doing just fine until it found an escape route.
Plug up that route, and everything is back to normal. If anything, after spewing this stuff to the surface it's less pressurised now.
The question is how to secure the hole, set some pipe into it, and then plug the hole. Ideally, you want make sure there is cement at the depth where this mud is coming from.
I don't know if that's at 9,300' below the surface or somewhere more shallow.