Abstract: Downhole apparatus comprises a base pipe and a plurality of non-concentric pressure deformable chambers mounted externally on the pipe. The chambers may be inflated to increase the diameter of the apparatus and engage and support a surrounding bore wall.

Abstract: There is disclosed a tubing expansion device and a method of expanding tubing. In one embodiment, an expansion device (10) is disclosed which comprises at least one expansion member (14) adapted to expand a tubing (12) by inducing a hoop stress in the tubing (12), and at least one further expansion member (16) adapted to expand the tubing (12) by inducing a compressive yield of the tubing (12); and a method of expanding tubing (12) comprising the steps of expanding the tubing (12) at least in part by inducing a hoop stress in the tubing (12), and expanding the tubing (12) at least in part by inducing a compressive yield of the tubing (12).

Abstract: Downhole apparatus comprises a base pipe and a plurality of non-concentric pressure deformable chambers mounted externally on the pipe. The chambers may be inflated to increase the diameter of the apparatus and engage and support a surrounding bore wall.

Abstract: Downhole apparatus comprises a base pipe and a plurality of non-concentric pressure deformable chambers mounted externally on the pipe. The chambers may be inflated to increase the diameter of the apparatus and engage and support a surrounding bore wall.

Abstract: Downhole apparatus for location in a bore which intersects a fluid-producing formation comprises a bore wall-supporting member configurable to provide and maintain a bore wall supporting force for a fluid-producing formation of at least 2 MPa, whereby fluid may flow from the formation into the bore. The bore wall supporting force may be utilized to modify or maintain the permeability of the rock adjacent the bore wall.

Abstract: Downhole apparatus comprises a base pipe and a plurality of non-concentric pressure deformable chambers mounted externally on the pipe. The chambers may be inflated to increase the diameter of the apparatus and engage and support a surrounding bore wall.

Abstract: Downhole apparatus comprises a base pipe and a plurality of non-concentric pressure deformable chambers mounted externally on the pipe. The chambers may be inflated to increase the diameter of the apparatus and engage and support a surrounding bore wall.

Abstract: Downhole apparatus for location in a bore which intersects a fluid-producing formation comprises a bore wall-supporting member configurable to provide and maintain a bore wall supporting force for a fluid-producing formation of at least 2 MPa, whereby fluid may flow from the formation into the bore. The bore wall supporting force may be utilised to modify or maintain the permeability of the rock adjacent the bore wall.

Abstract: An expandable coupling arrangement for coupling first and second tubulars includes a male thread portion on an end of the first tubular and a female thread portion on an end of the second tubular. The thread portions comprise dovetail threads having flanks, roots and crests, wherein the flanks are inclined at an angle of greater than 10°.

Abstract: A method of increasing the collapse resistance of a tubular comprises locating a tool having at least one, and typically three, bearing members within a tubular. The bearing members are positioned in engagement with a wall of the tubular to apply a radial force to a discrete zone of the wall. This radial force is then applied to further discrete zones of the wall, the level of radial force being selected such that the collapse resistance of the tubular is increased.

Abstract: A method of lining a drilled bore comprises running an expandable first tubular into a bore and locating a portion of the first tubular in an unlined section of the bore and another portion of the first tubular overlapping a portion of an existing second tubular. The first tubular is secured relative to the second tubular while retaining the provision of fluid outlets to permit displacement of fluid from an annulus between the first tubular and the bore wall. An expansion device is then run through the first tubular to expand the first tubular to a larger diameter. Cement is then circulated into the annulus between the expanded first tubular and the bore wall. The fluid outlets are then closed.

Abstract: The invention concerns the sealing of tubing, and in particular the sealing of a joint between expandable tubing sections. In one embodiment, there is disclosed expandable tubing such as an expandable liner comprising at least two expandable tubing sections which are adapted to be coupled together, and a seal adapted to be located around the expandable tubing sections, to seal a joint between the sections.

Abstract: Expandable tubing and methods seal a connection between expandable tubulars, and in particular, seal a connection between expandable tubulars post-expansion. In one embodiment, a method includes sealing a connection between expandable tubulars in the form of sections of an expandable liner. The method comprises the steps of connecting a first expandable tubular in the form of a first section of the liner and a second expandable tubular in the form of a second section of the liner. A seal is located between radially overlapping portions of the liner sections, and the seal is configured to maintain sealing between the liner sections both pre and post expansion.

Abstract: There are disclosed methods and apparatus for expanding tubing downhole. In one embodiment, there is disclosed a method of expanding downhole tubing such as a liner (10), the method comprising the steps of locating the liner (10) in a borehole (12), expanding a part (16) of the liner (10) in the borehole (12), locating an expansion device such as an expandable cone (18) in said expanded part (16) of the liner (10), and translating the cone (18) relative to the liner (10) to expand a further part (20) of the liner (10).

Abstract: An expandable coupling arrangement for coupling first and second tubulars includes a male thread portion on an end of the first tubular and a female thread portion on an end of the second tubular. The thread portions comprise dovetail threads having flanks, roots and crests, wherein the flanks are inclined at an angle of greater than 10°.

Abstract: There are disclosed methods and apparatus for expanding downhole tubing. In one embodiment, there is disclosed a method of expanding tubing comprising providing an assembly 40 comprising a section of expandable tubing (42) and an expansion device in the form of an expansion mandrel (44) located at least partially externally of the tubing (42), running the assembly (40) into a bore, translating the expansion mandrel (44) relative to the tubing (42) to expand an end section of the tubing (42), and further translating the expansion mandrel (44) relative to the tubing (42) to expand a further section of the tubing (42).

Abstract: An expansion apparatus for expanding a portion of a tubular comprises at least two expansion members adapted for selective deployment against a wall of a tubular. The expansion apparatus may be controlled to select a first expansion member to be deployed and the apparatus operated to expand a section of the tubular. The deployed expansion member may then be inactivated or retracted, such that the expansion member is no longer deployed against the wall of the tubular or is otherwise rendered inoperative, and a second expansion member can then be deployed and a further section of the tubular expanded.

Abstract: An expandable tubing assembly comprises a tubular connector defining overlapping longitudinal slots, the connector comprising end portions and an intermediate portion. The slots extend over the whole length of the connector, but the only slot overlap occurs in the intermediate portion. The assembly further comprises lengths of expandable tubing defining overlapping longitudinal slots and having end portions defining nodes between and beyond the ends of the tubing slots. Tubing threads are formed on the end most tubing nodes. The connector end portions define threads and are coupled with the threads formed on the nodes of the respective end portions of the tubing lengths.

Abstract: A downhole filter comprises a tubular member having a wall defining a plurality of openings. The openings have an outer width less than an inner width. The parts of the opening defining the smaller width are defined by radially outer parts of the openings, such that particulates or sand prevented from passing through the openings will tend to be retained to the outside of the tubular member. A method comprises providing a tubular string having a non-porous tubular portion and a porous tubular portion, and installing the tubular string within a wellbore such that the porous tubular portion is located adjacent a fluid-producing formation within the wellbore. In another embodiment, an apparatus comprises a drill string comprising a non-porous tubular portion and a porous tubular portion, and an earth removal member operatively connected to a lower end of the drill string.

Abstract: Apparatus (10) for facilitating coupling and cementing of downhole tubulars (12, 28) comprises a tubing section (12, 10) for use in lining a bore. The tubing section has upper and lower ends and defines a tubing wall having cement outlets (20) spaced from the lower end of the tubing. The lower end of the tubing is selectively closed, and swab cups (22) are provided externally of the lower end of the tubing below the cement outlets (20) for restricting passage of cement.