Abstract: A new wellbore apparatus has been invented which, in certain aspects, has anchor apparatus for anchoring the wellbore apparatus in a bore, the anchor apparatus actuated by fluid under pressure supplied thereto, and sealing apparatus selectively inflatable to close off the bore to fluid flow therethrough, and temperature compensating apparatus for maintaining a desired fluid pressure in the sealing apparatus to prevent it from bursting or deflating.

Abstract: A sealing apparatus for use in a well in connection with oil or gas production includes a seal and a pressure compensator. The seal is an inflatable, balloon-type well seal. The seal has a first cavity and is bears against an inner surface of a tubular surface. The pressure compensator is associated with the seal and includes a cylinder having a second cavity. The second cavity is in fluid communication with the first cavity. The cylinder has a reciprocatingly slidable piston positioned therein. The piston has first and second piston surfaces of different areas at opposite sides of the piston. The first piston surface is exposed to a first pressure value within the first cavity and the second piston surface is exposed to a second pressure value within the well.