| 摘要 |
An apparatus 100 has a housing 102 with an internal passage 104. When deployed, a barrier positions 150 in an upward direction in an annular space 112 between a biased sleeve 130 and the housing 102 folds towards one of its sides (156 figure 5a) to conform to the annular space. When debris collection is desired, operators lift the sleeve with a tool, the barrier rotates down and positions across the internal passage, and the tool releases the sleeve. In this stage, the barrier can collect debris to protect a downhole valve (20, figure 1). In further stages, operators open the downhole valve, and flow moves the barrier 150, a cage body 140, and sleeve together in upward direction. Eventually (figures 3a-3e), the sleeve is biased downward again, and the barrier positions within the annular space by reversibly folding towards its opposing side. In this position, barrier points in a downward direction and folds towards its opposing side to conform to the annular space. |
