PACKER

摘要

A packer (80) for use inside a casing (70) of a subterranean well includes a resilient element (84), a housing (104) and a rupture disc (124). The resilient element (84) is adapted to seal off an annulus (72) of the well wh en compressed, and the housing (104) is adapted to compress the resilient eleme nt (84) in response to a pressure exerted by fluid of the annulus (72) of a piston head (119) of the housing (104). The housing (104) includes a port (122) for establishing fluid communication with the annulus (72). The ruptur e disc (124) is adapted to prevent the fluid in the annulus (72) from entering the port (122) and contacting the piston head (119) until the pressure exert ed by the fluid exceeds a predetermined threshold and ruptures the rupture disc (124).