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 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: 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 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: 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).