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: A method and apparatus for removing fluid from a container using a conventional shaped charge such as those used in well perforation; the charge being spaced from the container wall, and producing an explosive jet, the explosive jet directed by a diffuser disk to provide a vent or drain.

Abstract: A method and system for processing image data in an image processing device for a plurality of pixel positions within a plurality of scanlines. The method and system includes storing a starting stamp value and a plurality of delta stamp values for the scanline. The stored values being used to generate a pixel stamp value for an input pixel in the scanline, by adding a starting value or previous pixel stamp value and the stored delta stamp value for the input pixel. Further includes receiving an input pixel intensity value for the input pixel and determining an output pixel intensity value. Subsequently, if the output pixel intensity value for the input pixel is equal to a value for a dot or hole the delta stamp values for at least one pixel having a location previous or subsequent to the input pixel can be updated.

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 method and apparatus for removing fluid from a container using a conventional shaped charge such as those used in well perforation; the charge being spaced from the container wall, and producing an explosive jet, the explosive jet directed by a diffuser disk to provide a vent or drain.

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.

Abstract: A method of providing a downhole seal, such as a packer, in a drilled bore between inner tubing and outer tubing comprises: providing an intermediate tubing section defining a seal arrangement for engaging with the inner tubing; and radially plastically deforming the intermediate tubing section downhole to form an annular extension. The extension creates a sealing contact with the outer tubing.

Abstract: A method and system for performing error diffusion is disclosed. An error value for a pixel may be received and used to determine one or more error diffusion values. The error diffusion values may be determined by performing bit shifting of the error value. Truncation of the error diffusion values may result in a difference between the error value and a sum of the error diffusion values. This difference may be compensated for by adding error compensation values to the error diffusion values to yield compensated error diffusion values. The compensated error diffusion values may then be diffused to appropriate destination pixels.

Abstract: A system and method for performing threshold stamping are disclosed. First and second threshold values corresponding to first and second pixels may be retrieved from a threshold memory. A plurality of upscaled threshold values may optionally be computed based on the first threshold value and the second threshold value. An (upscaled) threshold value may be updated at each of one or more first register blocks. A binary pixel value may be computed based at least in part on the first updated threshold value. The first updated threshold value may be updated at each of one or more second register blocks. A downscaled threshold value may optionally be computed based on a plurality of second updated threshold values. The downscaled threshold value or second updated threshold value may be damped in a damping circuit, and the damped threshold value may be stored in the threshold memory.

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.