Selvtettende, ekspanderende, oppblasbare tetningsstykker

The present invention generally relates to a sealing apparatus (50) for isolating a wellbore. In one aspect, the present invention provides an expandable sealing apparatus having an expandable tubular (48) and a sealing element (120) disposed around the tubular. A chamber (125) for maintaining a fluid is defined between the sealing element and the tubular. The sealing apparatus also includes a self-isolating layer (100) disposed in the chamber, wherein the self-isolating layer is adapted and arranged to regulate fluid flow through the chamber. Fluid supplied to the chamber may inflate the sealing element, thereby urging the sealing element into contact with the wellbore. When the pressure in the tubular is released, the pressure in the chamber causes the self-isolating layer to close off, thereby retaining the pressure in the chamber.