摘要:
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°.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Methods and apparatus for segmenting image data into windows and rendering a best-estimate outline delineating document windows may include adjusting a background white threshold differently than adjusting a white threshold normally used to classify pixels as white for video processing purposes. Such an independently arrived at threshold may be more suitable for the different task of differentiating between document background and document content.
摘要:
A method of isolating a section of downhole tubing comprises: running a length of expandable tubing (20) into a tubing-lined borehole (12, 14) and positioning the expandable tubing (20) across a section of tubing to be isolated; deforming at least portions of the expandable tubing (36, 40) to increase the diameter of the portions to sealingly engage the tubing (14) and to isolate the tubing section.
摘要:
A tubing connection arrangement that includes two expandable tubing sections is disclosed. In one embodiment, each of the tubing sections includes a filter screen sandwiched between inner expandable tubing and outer expandable tubing. On expansion of the tubing sections, the outer tubing provides resistance to radial expansion of the inner tubing in order to ensure that the integrity between the tubing sections is maintained. The filter screen of one of the tubing sections overlaps the filter screen of the other tubing section, and the outer expandable tubing of at least one of the tubing sections extends over the overlapping filter screens.
摘要:
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.
摘要:
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.
摘要:
A method and apparatus is provided for drilling and lining a wellbore in one downhole trip. The method comprises mounting a drill bit on a drill string including a section of expandable tubing and providing a tubing expander in the string, then rotating the drill bit and advancing the drill string through a bore, then passing the expander through the expandable tubing to expand the tubing, wherein the expandable tubing is deformed by compressive plastic deformation of the tubing with a localised reduction in wall thickness, resulting in a subsequent increase in tubing diameter, and then retrieving the drill bit from the bore through the expanded tubing. The apparatus comprises a drill string including a section of expandable tubing, a drill bit mounted on the string, and a tubing expander mounted on the string, wherein the expandable tubing is deformed by compressive plastic deformation of the tubing with a localised reduction in wall thickness, resulting in a subsequent increase in tubing diameter and wherein the drill bit may be retrieved through the expanded tubing.