isolation device sealingly engaged to the section the first isolation device may be a pressure actuated valve and the second isolation device may be a plug application_number US 73797807 A description one or more illustrative embodiments incorporating the invention disclosed herein are presented below not all features of an actual implementation are necessarily described or shown for the sake of clarity for example the various seals vents and others design details common to oil well equipment are not specifically illustrated or described it is understood that in the development of an actual embodiment incorporating the present invention numerous implementation specific decisions must be made to achieve the developer 39 s goals such as compliance with system related business related and other constraints which vary by implementation and from time to time while a developer 39 s efforts might be complex and time consuming such efforts would be nevertheless a routine undertaking for those of ordinary skill the art having benefit of this disclosure also the use in this application of relative terms such as but not limited to left right up down inside and outside is not meant to preclude interchanging one for the other in other embodiments such relative terms are merely used for clarity of discussion of the particular embodiments disclosed herein in general terms a formation isolation system has been created comprising a first isolation device integral with the isolation system in the well bore and a second isolation device that is not integral with the isolation system which devices in combination isolate the formation of interest the first isolation device may comprise a valve such as a mechanical on off valve a variable choke valve a shifting sleeve valve a hydraulic or.