摘要 |
<p>A deployment system for use in an oil well system or the like that comprises a body for disposition in an elongated tubular casing that carries deployable apparatus for radial expansion into engagement with surfaces of the casing. A first chamber in the body contains incompressible fluid, and a second chamber in the body contains pressurized compressible fluid. A first passage interconnects the first chamber and the deployable apparatus, a second passage interconnects the first and second chambers, and differential pressure responsive means that controls the second passage has a first condition in which the second passage is closed and a second condition in which the second passage is open, the differential pressure responsive means being adapted to shift from the first condition to the second condition when the pressure in the first chamber exceeds the pressure in the second chamber by a predetermined amount.</p> |