| 摘要 |
The present invention relates to an annular barrier to be expanded in an annulus between a well tubular structure and a wall of a borehole downhole for providing zone isolation between a first zone having a first pressure and a second zone having a second pressure of the borehole. The annular barrier comprises a tubular metal part for mounting as part of the well tubular structure, the tubular metal part having an outer face; an expandable sleeve surrounding the tubular metal part and having an inner face facing the tubular metal part and an outer face facing the wall of the borehole, each end of the expandable sleeve being connected with the tubular metal part; and an annular space between the inner face of the expandable sleeve and the tubular metal part, the annular space having a space pressure. The annular barrier comprises an anti-collapsing unit comprising an_element movable at least between a first position and a second position, the anti-collapsing unit having a first inlet which is in fluid communication with the first zone, and a second inlet which is in fluid communication with the second zone, and the anti-collapsing unit having an outlet which is in fluid communication with the annular space, and in the first position, the first inlet is in fluid communication with the outlet, equalising the first pressure of the first zone with the space pressure, and in the second position, the second inlet is in fluid communication with the outlet, equalising the second pressure of the second zone with the space pressure. The present invention furthermore relates to a downhole system and a zone isolation method. |
