Differential pressure indicator for downhole isolation valve

摘要

DIFFERENTIAL PRESSURE INDICATOR FOR DOWNHOLE ISOLATION A differential pressure indicator (DPI) (40) for use with a downhole isolation valve (50) includes a tubular mandrel (41m) for assembly as part of a casing string (11) and for receiving a tubular string (5). The mandrel (41m) has a stop shoulder (42h) and a piston shoulder (43p). The DPI (40) further includes a tubular housing (41h) for assembly as part of the casing string (11) and for receiving the tubular string (5). The housing (41h) is movable relative to the mandrel (41m) between an extended position and a retracted position and has a stop shoulder (44h) and a piston shoulder (44p). The DPI (40) further includes a hydraulic chamber (46c) formed between the piston shoulders (43p, 44p) and a coupling (46c) in communication with the hydraulic chamber (46c) and for connection to a sensing line (37s). The housing (41h) is movable relative to the mandrel (41m) and to the extended position in response to tension exerted on the DPI (40). ________________ -3/6 _ _ _ _ _ _ _ _ 46f 44 u 4 7a 42 41 m 42h 4 44h 43u4m 44 44p 444 7b 43p, -61 46c 41 h if 47c 43m 44b 45 44s 43s 45u 43b 47d __ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ 45h 45b 47e