Abstract: A retrievable self-energizing top anchor tool with a central energizing mandrel disposed around a central tool bore and a set of anchor segments distributed around a circumference of the central energizing mandrel, each having one or more wedge surfaces facing toward the central tool bore and corresponding to and engaging inclined surfaces of the central energizing mandrel. The tool is releasable by relative upward movement of a release sub against a release sub stop arranged within the central tool bore. A release mechanism houses one or more pre-loaded release spring members locked with a release locking mechanism. When unlocked the release spring members exert a retracting bias force on the central energizing mandrel in downward direction along the longitudinal axis relative to the set of anchor segments. This downward movement of the central energizing mandrel causes a radially inward movement of the set of anchor segments.

Abstract: An annular space surrounding an expandable well tubular (1) is sealed by: —a concave seal pusher assembly (5) with concave pusher elements comprising buckling joints (7) of which assembly (5) a first end is secured at a selected first location (2) of the outer surface of the unexpanded well tubular (1); —an annular elastomeric sealing ring (9) arranged with an inwardly tapered first end thereof against an outwardly tapered second end (8) of the concave seal pusher assembly (5); —a set of staggered and overlapping steel support strips (11) arranged around a second end of the sealing ring (9) and connected at one end thereof to a selected second location (3) of the outer surface of the unexpanded tubular (1); —expanding and thereby shortening the tubular (1) to push the inwardly tapered end of the sealing ring over the outwardly tapered end (8) of the seal pusher assembly (5) and buckling the staggered strips (11) against the outer surface (12) of the annular space surrounding the expanded tubular (1) to compre

Abstract: A to be expanded tubular (4) can be locked to a previously installed host casing (2) using a self energizing top anchor (SETA) tool. This SETA tool has an anchoring section with a set of anchoring slips (1), and a centralizer which is connected to the body of the anchoring section. The anchoring slips (1) engage the host casing (2) once an expansion cone (3) presses the tubular against the shoulder of the centralizer. The SETA tool is further provided with a guide nose (7) to which a force transmission sub (8) is connected.

Abstract: A hydraulically actuated Jack And Pull (JAP) tubular expansion tool string comprises: an annular non-return valve arranged in the wall of the JAP string, which allows mud to flow from a surrounding annulus into the bore of the expansion tool string when the pressure in the bore of the tool string is lower than that in the annulus; a second non-return valve arranged in the JAP string below the annular valve which allows fluid to move down only; wherein during the cycling of the jack the annular non-return valve is continuously open and the second non-return valve cycles with the jack movement to inhibit curing of cement in the expansion tool string.

Abstract: A retrievable self-energizing top anchor tool with a central energizing mandrel disposed around a central tool bore and a set of anchor segments distributed around a circumference of the central energizing mandrel, each having one or more wedge surfaces facing toward the central tool bore and corresponding to and engaging inclined surfaces of the central energizing mandrel. The tool is releasable by relative upward movement of a release sub against a release sub stop arranged within the central tool bore. A release mechanism houses one or more pre-loaded release spring members locked with a release locking mechanism. When unlocked the release spring members exert a retracting bias force on the central energizing mandrel in downward direction along the longitudinal axis relative to the set of anchor segments. This downward movement of the central energizing mandrel causes a radially inward movement of the set of anchor segments.

Abstract: A system for radially expanding a tubular element (2) in an underground borehole (3) comprises an expansion string (16) extending into the tubular element (2) and including an expander (27) and a jack device (24) for pulling the expander (27) through the tubular element (2) so as to radially expand the tubular element (2). The jack device (24) is provided with an anchor (28) having at least one slip element (50) adapted to be radially moved against the inner surface of the tubular element (2). A cage (14) is positioned above the tubular element (2), which cage (14) is surrounded by a cylindrical wall and adapted to receive the anchor (28) and to be radially expanded by the anchor (28) against said cylindrical wall.

Abstract: A hybrid push and pull method for expanding a tubular in a wellbore utilizes an expansion assembly with a sealed and another, optionally expandable, cone, wherein during at least part of the expansion process the sealed cone is moved up through the tubular by a combination of push and pull forces and the push force is generated by pumping fluid at an elevated pressure into a space between the bottom plug and the expansion assembly. This allows staged expansion of the tubular in a hard rock formation and/or of a tubular surrounded by a hardened cement lining and/or of a pair of partially overlapping nested tubular ends.

Abstract: An anchoring system for anchoring a tool (24) in a downhole tubular element (2) comprises: —an anchor (28) having a central body (40) connected to, or integrally formed with, the tool (24); —a slip element (50) radially movable relative to the central body (32) between a retracted and an expanded position against the inner surface of the tubular element (2), —a primary spring (56) for moving the slip element to the expanded position; —a control device comprising a stop member (60) against which the slip element (50) is pushed by the primary spring (56); and —a secondary spring (58) acting on the stop member (60) to move each slip element (50) to its retracted position.

Abstract: In an assembly for lowering and expanding a tubular element in a borehole on an expansion string, at least part of the weight of the tubular element is transmitted to the expansion string via an internal upset and a support protruding from an outer surface of the expansion string below the internal upset.

Abstract: In an expansion assembly (1), an expandable bottom plug (10) is arranged below a primary expander (6) for expanding a tubular element (2). The expandable bottom plug (10) includes an expandable tubular clad element with a sealing section for sealing the expanded clad element to a lower portion of the expanded tubular element (2), and an anchoring section for anchoring the expanded clad element to the lower portion of the expanded tubular element. A secondary expander (22) is provided for radially expanding the clad element in the lower portion of the expanded tubular element by axial movement of the secondary expander through the clad element.

Abstract: An annular space surrounding an expandable well tubular (1) is sealed by: —a concave seal pusher assembly (5) with concave pusher elements comprising buckling joints (7) of which assembly (5) a first end is secured at a selected first location (2) of the outer surface of the unexpanded well tubular (1); —an annular elastomeric sealing ring (9) arranged with an inwardly tapered first end thereof against an outwardly tapered second end (8) of the concave seal pusher assembly (5); —a set of staggered and overlapping steel support strips (11) arranged around a second end of the sealing ring (9) and connected at one end thereof to a selected second location (3) of the outer surface of the unexpanded tubular (1); —expanding and thereby shortening the tubular (1) to push the inwardly tapered end of the sealing ring over the outwardly tapered end (8) of the seal pusher assembly (5) and buckling the staggered strips (11) against the outer surface (12) of the annular space surrounding the expanded tubular (1) to compre

Abstract: A method for expanding a lower bell section of an expandable tubular to a larger diameter than upper parts thereof utilizes an expandable bell cone (1) with circumferentially spaced segments (2) that expand in response to axial force and automatically retract in response to removal of the axial force, wherein gaps (A) are present between the expanded segments (2) and the tailends (2A) at the gauge of the segments are slightly skewed to mitigate the effect of the gaps (A) on the flattening of the expanded bell sections between the segments (2).

Abstract: The functionality of a downhole tubular expansion tool is switched by: -providing the unexpanded tubular with an oversized section (7) having a larger internal width than other (non-oversized) sections of the unexpanded tubular (6);-providing the expansion tool with a control sub (1) comprising a trigger assembly (2) that is pushed outward within the oversized section and thereby switches the functionality of the tool, for example by contracting or expanding a collapsible expansion cone and/or opening a valve.

Abstract: A system for sealing an expandable tubular connection (2, 20) in a wellbore comprises an annular resilient seal (32, 34) arranged in an annular groove (90) defining a section (82) of reduced wall thickness of an inner tubular element (20), which section (82) is subject to surplus expansion induced by an expansion cone such that, in the expanded state of the inner tubular element (20), the annular groove (90) has a wave-shaped profile thereby compressing the annular seal (32, 34) against an outer tubular element (2).

Abstract: A to be expanded tubular (4) can be locked to a previously installed host casing (2) using a self energizing top anchor (SETA) tool. This SETA tool has an anchoring section with a set of anchoring slips (1), and a centralizer which is connected to the body of the anchoring section. The anchoring slips (1) engage the host casing (2) once an expansion cone (3) presses the tubular against the shoulder of the centralizer. The SETA tool is further provided with a guide nose (7) to which a force transmission sub (8) is connected.

Abstract: A hybrid push and pull method for expanding a tubular in a wellbore utilizes an expansion assembly with a sealed and another, optionally expandable, cone, wherein during at least part of the expansion process the sealed cone is moved up through the tubular by a combination of push and pull forces and the push force is generated by pumping fluid at an elevated pressure into a space between the bottom plug and the expansion assembly. This allows staged expansion of the tubular in a hard rock formation and/or of a tubular surrounded by a hardened cement lining and/or of a pair of partially overlapping nested tubular ends.

Abstract: A hydraulically actuated Jack And Pull (JAP) tubular expansion tool string comprises: an annular non-return valve arranged in the wall of the JAP string, which allows mud to flow from a surrounding annulus into the bore of the expansion tool string when the pressure in the bore of the tool string is lower than that in the annulus; a second non-return valve arranged in the JAP string below the annular valve which allows fluid to move down only; wherein during the cycling of the jack the annular non-return valve is continuously open and the second non-return valve cycles with the jack movement to inhibit curing of cement in the expansion tool string.

Abstract: A system for radially expanding a tubular element (2) in an underground borehole (3) comprises an expansion string (16) extending into the tubular element (2) and including an expander (27) and a jack device (24) for pulling the expander (27) through the tubular element (2) so as to radially expand the tubular element (2). The jack device (24) is provided with an anchor (28) having at least one slip element (50) adapted to be radially moved against the inner surface of the tubular element (2). A cage (14) is positioned above the tubular element (2), which cage (14) is surrounded by a cylindrical wall and adapted to receive the anchor (28) and to be radially expanded by the anchor (28) against said cylindrical wall.

Abstract: An anchoring system for anchoring a tool (24) in a downhole tubular element (2) comprises: an anchor (28) having a central body (40) connected to, or integrally formed with, the tool (24); a slip element (50) radially movable relative to the central body (32) between a retracted and an expanded position against the inner surface of the tubular element (2), a primary spring (56) for moving the slip element to the expanded position; a control device comprising a stop member (60) against which the slip element (50) is pushed by the primary spring (56); and a secondary spring (58) acting on the stop member (60) to move each slip element (50) to its retracted position.

Abstract: In an assembly for lowering and expanding a tubular element in a borehole on an expansion string, at least part of the weight of the tubular element is transmitted to the expansion string via an internal upset and support means protruding from an outer surface of the expansion string below the internal upset.