| 摘要 |
A down hole shut-in device effects a stoppage of effluent from a blown-out oil well by freezing a plug of the effluent within the well. The down hole shut-in device is installed within a conventional tubing string or casing string and includes a tubular member having a structural outer wall and a relatively thin, heat-exchanging inner wall. During normal operations, a substantially non-compressible fluid is maintained within the volume bounded by the outer and inner walls for transmitting pressure exerted upon the thin inner wall to the structural outer wall. During a blow-out or other loss of well control, the substantially non-compressible fluid is replaced by a refrigerated fluid for removing heat from the effluent flowing within the tubular member. A series of flow deflectors are mounted to the inner wall and are normally flush therewith. Upon being cooled by circulation of the refrigerated fluid, the flow deflectors assume a curved shape and project into the path of the effluent, whereupon full deflector deployment ensues. Upon being deployed, the flow deflectors absorb heat from the effluent, deflect the effluent against the cold inner wall, and provide structural support for a condensed layer of effluent which eventually closes upon itself to form a frozen plug within the tubular member.
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