Abstract: Retrievable packer for operations in wells cased by means of a casing pipe, the packer being applied in operations involving very high pressures, of up to about 15,000 psi, wherein the packer comprises a connecting head for being fixed to a service pipe, an upper mandrel threaded at a lower mandrel, a balancing liner holder concentrically arranged on the upper mandrel so as to form a space of hydraulic pressure between both, within which space one balancing liner is accommodated, designed to apply a downward force on an annular ledge of the upper mandrel, to offset upwards thrust forces that operate on the tool and the service pipe.