A while back I asked where they were when they los

A while back I asked where they were when they lost circulation if it was near the pay zone , if not that mud won't be coming back . And I don't know how they can retrieve that mud if its behind unperfed casing I must be missing something . And what I know about limestone the acid opens up pours to let the fluid travel towards the well bore . But if they are getting that lost mud now they must have fired the guns down hole.