초록 ▼

The mandrel comprises a body having a longitudinal axis together with a radially-expandable annular assembly. The annular assembly presents a peripheral surface for pressing against a borehole and a peripheral surface for pressing against the body. Around the longitudinal axis, the annular assembly

The mandrel comprises a body having a longitudinal axis together with a radially-expandable annular assembly. The annular assembly presents a peripheral surface for pressing against a borehole and a peripheral surface for pressing against the body. Around the longitudinal axis, the annular assembly comprises a plurality of radial-expansion blocks. Each block has a first bearing surface, a second bearing surface, and two side surfaces disposed respectively facing a side surface of at least one adjacent block. The block are displaceable relative to one another between a radially-contracted configuration, and a radially-expanded, engagement configuration in which each side surface of a block is in contact with the side surface of the adjacent block.

대표청구항 ▼

The invention claimed is: 1. A mandrel for insertion in a borehole in which a fluid circulates, the mandrel comprising: a body having a longitudinal axis; and a radially-expandable annular assembly attached to the body, the radially-expandable annular assembly including: a first peripheral surface

The invention claimed is: 1. A mandrel for insertion in a borehole in which a fluid circulates, the mandrel comprising: a body having a longitudinal axis; and a radially-expandable annular assembly attached to the body, the radially-expandable annular assembly including: a first peripheral surface for pressing against the borehole; a second peripheral surface for pressing against the body; and a plurality of radial expansion blocks, each radial expansion block of the plurality of radial expansion blocks having a first bearing face defining a portion of the first peripheral surface, a second bearing face defining a portion of the second peripheral surface, and two side surfaces disposed on opposite sides of the radial expansion block, the plurality of radial expansion blocks being disposed about the longitudinal axis of the body so that each side surface of each radial expansion block faces a side surface of an adjacent radial expansion block, wherein radial expansion blocks of the plurality of radial expansion blocks are displaceable relative to one another, and wherein the radially-expandable annular assembly has a radially-expanded, engaged configuration in which each side surface of each radial expansion block is pressed against the side surface of the adjacent block, and the radially-expandable annular assembly has a radially-contracted configuration having a radial size smaller than a radial size of the radially-expandable annular assembly in the radially-expanded, engaged configuration, wherein the body includes a block-bearing surface, wherein the first bearing face of each radial expansion block is substantially cylindrical about the longitudinal axis and the second bearing face of each radial expansion block is inclined relative to the longitudinal axis, wherein, for each radial expansion block, the first bearing face and the second bearing face are interconnected by the two side surfaces, wherein at least one radial expansion block of the plurality of radial expansion blocks is mounted so as to be able to slide longitudinally over the block-bearing surface between a position in which the radially-expandable annular assembly is in the radially-contracted configuration and a position in which the radially-expandable annular assembly is in the radially-expanded, engaged configuration, and wherein the block-bearing surface is inclined relative to the longitudinal axis. 2. The mandrel according to claim 1, wherein the radial expansion blocks are displaceable relative to one another by sliding, each side surface of each radial expansion block being configured to slide along the side surface of the adjacent radial expansion block, and wherein the side surfaces are shaped to be able to cause the annular assembly to expand radially by a wedging effect. 3. The mandrel according to claim 1, wherein at least a first radial expansion block of the plurality of radial expansion blocks includes a first side surface and a second side surface, the first side surface converging toward the second side surface in a direction along the longitudinal axis, and wherein at least a second radial expansion block of the plurality of radial expansion blocks adjacent to the first radial expansion block includes a first side surface and a second side surface, the first side surface diverging away from the second side surface in the direction along the longitudinal axis. 4. The mandrel according to claim 3, wherein each radial expansion block is substantially trapezoidal in shape, wherein a height direction of each trapezoidal shape is substantially parallel to the longitudinal axis, and wherein the plurality of radial expansion blocks is further disposed about the longitudinal axis of the body so that respective radial expansion blocks alternate in orientation with respect to the longitudinal axis. 5. A mandrel according to claim 1, wherein the block-bearing surface defines a top abutment for blocking at least one radial expansion block of the plurality of radial expansion blocks in position. 6. The mandrel according to claim 1, wherein the annular assembly has pressing means for pressing at least one radial expansion block of the plurality of radial expansion blocks against the block-bearing surface. 7. The mandrel according to claim 1, wherein each radial expansion block comprises: a reinforcement including a top edge and/or a bottom edge, the reinforcement defining an outer annular housing that is open at outer side surfaces; and an outer sealing gasket placed in the outer annular housing, and wherein in the radially-expanded, engaged configuration, outer annular housings of adjacent radial expansion blocks communicate with one another through side surfaces around at least one periphery of the longitudinal axis. 8. The mandrel according to claim 7, wherein the reinforcement further defines an inner annular housing open at inner side surfaces, wherein each radial expansion block has an inner sealing gasket placed in the inner annular housing, and wherein in the radially-expanded, engaged configuration, inner annular housings of adjacent radial expansion blocks communicate with one another through side surfaces around at least one periphery of the longitudinal axis. 9. The mandrel according to claim 1, further comprising one or more anchor members for anchoring to the borehole, the one or more anchor members being radially deployable relative to the body and disposed under the radially-expandable annular assembly. 10. A well for working a fluid, the well comprising: a borehole; and the mandrel according to claim 1 disposed in the borehole. 11. The well according to claim 10, wherein the borehole comprises: a first tube; a second tube; and a sleeve interconnecting the first and second tubes, the sleeve having an annular groove for receiving the radially-expandable annular assembly, and having a diameter greater than a mean diameter of a central passage, wherein the first tube, the second tube, and the sleeve define a fluid flow passage, and wherein the radially-expandable annular assembly in its radially-expanded, engaged position is pressed against an outer wall of the annular groove. 12. The well according to claim 11, wherein the sleeve comprises a projection for blocking the annular assembly in position, the projection projecting inwardly into the central passage relative to the first tube and to the second tube, a top edge of the radially-expandable annular assembly being jammed axially against the projection. 13. The mandrel according to claim 1, wherein the block-bearing surface is conical in shape. 14. The mandrel according to claim 1, wherein the first peripheral surface is continuous over at least one circumference thereof in the radially-expanded, engaged configuration of the radially-expandable annular assembly, and wherein the second peripheral surface is continuous over at least one circumference thereof and is pressed against the block-bearing surface to provide sealing between the radially-expandable annular assembly and the body in the radially-expanded, engaged configuration of the radially-expandable annular assembly. 15. A mandrel for insertion in a borehole in which a fluid circulates, the mandrel comprising: a body having a longitudinal axis; a radially-expandable annular assembly attached to the body, the radially-expandable annular assembly including: a first peripheral surface for pressing against the borehole; a second peripheral surface for pressing against the body; and a plurality of radial expansion blocks each radial expansion block of the plurality of radial expansion blocks having a first bearing face defining a portion of the first peripheral surface, a second bearing face defining a portion of the second peripheral surface, and two side surfaces disposed on opposite sides of the radial expansion block, the plurality of radial expansion blocks being disposed about the longitudinal axis of the body so that each side surface of each radial expansion block faces a side surface of an adjacent radial expansion block, wherein radial expansion blocks of the plurality of radial expansion blocks are displaceable relative to one another, wherein the radially-expandable annular assembly has a radially-expanded, engaged configuration in which each side surface of each radial expansion block is pressed against the side surface of the adjacent block, and the radially-expandable annular assembly has a radially-contracted configuration having a radial size smaller than a radial size of the radially-expandable annular assembly in the radially-expanded engaged configuration; and an expansion means for radially expanding the radially-expandable annular assembly, wherein the expansion means includes a drive member releasably secured to at least one first block of the plurality of radial expansion blocks and secured to at least one second block of the plurality of radial expansion blocks, the drive member being movable longitudinally relative to the body and having: a rest position in which the at least one first block and the at least one second block are secured to the drive member, the radially-expandable annular assembly occupying its radially-contracted configuration; an intermediate position in which the at least one first block is free relative to the drive member and substantially stationary relative to the body; and an active position for engagement of the at least one first block and the at least one second block, in which the radially-expandable annular assembly occupies its radially-expanded, engaged configuration. 16. The mandrel according to claim 15, further comprising: means for pressing the drive member from its active position towards its intermediate position; and releasable means for keeping the drive member in its active position.