It is determined, that influence of karsting on reservoir properties of productive carbonates is significant, but not synonymous. It is noted, that high interblock storage capacity of fractured reservoir is inadequate to similarly significant permeability, and, on the contrary, local closed "nests" of karsted fractures sometimes appear to be highly permeable but low storage capacity reservoir. A conclusion is made, that karsting of water-bearing carbonate deposits forms super reservoirs with unique filtration-storage capacity properties, which take-in thousands of cubic meters of drilling mud and tens of tons of cement.