Annular barrier with a valve system

Abstract

The present invention relates to an annular barrier for providing zonal isolation in an annulus in a well downhole between a well tubular metal structure and another well tubular metal structure or a wall of a borehole, comprising a tubular metal part configured to be mounted as part of the well tubular metal structure, an expandable metal sleeve connected with and surrounding the tubular metal part forming an annular space there between, the expandable metal sleeve is configured to be expanded in the well downhole from a first outer diameter to a second outer diameter to abut against the well tubular metal structure or the wall of the borehole, and an expansion opening in the tubular metal part wherein the annular barrier further comprises a valve system comprising an isolation valve having a first position and a second, comprising an isolation bore, an isolation piston arranged in the isolation bore dividing the bore into a first bore part and a second bore part in the first position, the isolation piston is maintained in the first position by a shear element configured to break at a predetermined pressure difference between the first bore part and the second bore part, a first aperture arranged in the first bore part and being in fluid communication with the annular space, a second aperture arranged in the first bore part and being in fluid communication with the expansion opening through a first fluid channel, a third aperture arranged in the second bore part and being in fluid communication with the expansion opening through a second fluid channel, wherein in the first position the first aperture is in fluid communication with the second aperture, and in the second position the isolation piston prevents fluid communication between the first aperture and the second aperture.