Abstract: A tubular pull string assembly (5, 5A) may be used to pull up an expansion mandrel (1) through an area of overlap (2) between an upper section of a well liner (3) expanded by the expansion mandrel and a lower section of a previously installed liner (4). The tubular pull string assembly may be provided with at least one flow port (6), through which fluid is permitted to flow from the exterior (7) to the interior (8) of the tubular pull string assembly during pop out of the expansion mandrel from the area of overlap. In addition thereto, or instead thereof, the expansion mandrel may be provided with a streamlined tail (1A) section having an inwardly tapered outer surface (11) that intersects a longitudinal axis of the expansion mandrel at a sharp angle. The sharp angle can be less than 20 degrees. The tail section can have a length of at least several centimeters.

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 tubular member (1) with a relative rough (1.5-10 ?m) inner surface (5) coated solid lubricating film (10) which is transformed into a substantially viscous rubbery viscoelasto-plastic phase at temperatures in a range between 50° C. and 110° C. is expanded by moving an expansion member (24) with a relatively smooth outer surface (roughness<1.5 ?m) therethrough, such that during expansion a viscous viscoelastoplastic substantially rubbery lubricating film (44) is generated between the tubular member (1) and the expansion mandrel (24), which film remains bonded to the rough inner surface (5) of the expanded tubular (1), but does not stick to the relatively hot and smooth expansion member (24).

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: An expansion assembly for expanding a tubular in a wellbore, the expansion assembly including a top anchor comprising: a workstring; a pusher ring being coupled to the workstring by a first releasable coupling; a ramp body having one or more ramp surfaces, said ramp body being releasably coupled to the workstring by a second releasable coupling; one or more anchor segments each having one or more wedge surfaces corresponding to and engaging the ramp surfaces of the ramp body, one end of the segments engaging the pusher ring; a release ring enclosing the workstring and arranged at an opposite end of the segments; one or more key merlons connecting the release ring to the pusher ring; and activating means for releasing the first releasable coupling.

Abstract: A well tubular is expanded using an expandable segmented cone (301-303) which is at a large diameter bottom or gauge section of the cone (301-303) provided with a robust sealing assembly (300A-C) comprising a sealing ring or sealing lips that engage(s) an expanded section of the tubular (307).

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 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 tubular pull string assembly (5, 5A) may be used to pull up an expansion mandrel (1) through an area of overlap (2) between an upper section of a well liner (3) expanded by the expansion mandrel and a lower section of a previously installed liner (4). The tubular pull string assembly may be provided with at least one flow port (6), through which fluid is permitted to flow from the exterior (7) to the interior (8) of the tubular pull string assembly during pop out of the expansion mandrel from the area of overlap. In addition thereto, or instead thereof, the expansion mandrel may be provided with a streamlined tail (1A) section having an inwardly tapered outer surface (11) that intersects a longitudinal axis of the expansion mandrel at a sharp angle. The sharp angle can be less than 20 degrees. The tail section can have a length of at least several centimeters.

Abstract: A low break out screw threaded safety joint for releasably connecting a Bottom Hole Assembly (BHA) of a well tubular expansion assembly to a drill string comprises a pair of intermeshing TOothed MAte (TOMA) rings (24) with intermeshing sawtooth profiles (25,26) teethed profiles that have a low break out performance upon reverse rotation of the drill string relative to the BHA, which may be stuck within the wellbore.

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 expansion assembly for expanding a tubular in a wellbore, the expansion assembly including a top anchor comprising: a workstring; a pusher ring being coupled to the workstring by a first releasable coupling; a ramp body having one or more ramp surfaces, said ramp body being releasably coupled to the workstring by a second releasable coupling; one or more anchor segments each having one or more wedge surfaces corresponding to and engaging the ramp surfaces of the ramp body, one end of the segments engaging the pusher ring; a release ring enclosing the workstring and arranged at an opposite end of the segments; one or more key merlons connecting the release ring to the pusher ring; and activating means for releasing the first releasable coupling.

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 upward force exerted on an expansion cone (2), which is pulled up by a drill string (3) to expand a well tubular (1), is hydraulically enhanced by:—connecting a bottom plug (10) to a carrier body (11) below the expansion cone (2);—lowering the drill string (3), cone (2), carrier body (11), bottom plug (10) and unexpanded well tubular (1) assembly into a well;—inducing the drill string (3) to pull the expansion cone (2) through a lower edge (13) of the unexpanded well tubular (1) to expand said edge (13) and to subsequently pull the bottom plug (10) into sealing engagement with the expanded edge (13);—releasing the bottom plug (10) from the carrier body (11);—further pulling (F1) the expansion cone (10) through the well tubular (1) and simultaneously injecting fluid through the drill string (3) below the cone (2) to hydraulically increase (F2) the upward force (F=F1+F2) exerted on the expansion cone (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 well tubular is expanded using an expandable segmented cone (301-303) which is at a large diameter bottom or gauge section of the cone (301-303) provided with a robust sealing assembly (300A-C) comprising a sealing ring or sealing lips that engage(s) an expanded section of the tubular (307).

Abstract: A tubular member (1) with a relative rough (1.5-10 ?m) inner surface (5) coated solid lubricating film (10) which is transformed into a substantially viscous rubbery viscoelasto-plastic phase at temperatures in a range between 50° C. and 110° C. is expanded by moving an expansion member (24) with a relatively smooth outer surface (roughness <1.5 ?m) therethrough, such that during expansion a viscous viscoelastoplastic substantially rubbery lubricating film (44) is generated between the tubular member (1) and the expansion mandrel (24), which film remains bonded to the rough inner surface (5) of the expanded tubular (1), but does not stick to the relatively hot and smooth expansion member (24).

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).