Sealing system for a well bore in which a hot fluid is circulated
AssigneeSociete Nationale Elf Aquitaine (Production)
InventorMiffre Hubert
Life of this patent
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Abstract
A sealing system for a tubing string in a well bore which is capable of undergoing deformation under the action of a hot fluid and has at least one casing string in which the tubing is housed, a connecting and sealing assembly placed between the casing and the tubing as well as members for supporting and securing the casing and tubing strings comprises in addition, a hollow seal support, the upper end of which is rigidly fixed and the lower end of which is free to permit displacement of the upper portion of the tubing string with respect to the seal support with the lower portion of the tubing string rigidly fixed to the connecting and sealing assembly located near the bottom of the well bore.
Claims32
A sealing system for a well bore of the type in which a hot fluid is circulated, comprising a wellhead unit, at least one tubing string which is capable of undergoing deformation under the action of the hot fluid circulating within said tubing string, at least one casing string provided with a perforated zone opposite to a permeable producing formation, said tubing string being housed within said casing string, a connecting and sealing assembly above the perforated zone operatively interposed between the casing string and the tubing string to support said tubing string, casing string support members for supporting and securing said casing string mounted at or connected to the wellhead unit, a hollow seal support having an upper end rigidly fixed to a stationary member of the wellhead unit and a portion telescopingly engaging in and opening into the top portion of the tubing string to form an annulus between said lower portion of said seal support and said top portion of said tubing string, said top portion of the tubing string being free and capable of moving with respect to the seal support with the bottom portion of said tubing string rigidly fixed to said connecting and sealing assembly placed near the bottom of the well bore, seal means operatively interposed between the telescoping portions of said seal support and tubing string in said annulus to seal the annulus formed by and between said telescoping portions upon the application of pressure to at least one end of said seal means, and pressure means to apply pressure to said at least one end of said seal means.
Tubing for a well bore extending from a wellhead to a producing formation through subsurface formations and having means for cooperating with a packer disposed between said tubing and a casing which surrounds said tubing, fluid-tight seals being provided by said packer between said casing and the lower portion of said tubing, wherein said tubing comprising:
- a hollow body extending approximately from said wellhead to said producing formation;
- a hollow seal support member disposed within said hollow body, the upper end of said hollow seal support member being adapted to extend outwards from said hollow body and being attached to said wellhead;
- sealing means disposed between said hollow body and hollow seal support member for providing a fluid-tight seal therebetween, the upper part of said hollow body being free to move towards said wellhead when said tubing is in operation.
Dependencies are inferred from the claim text.