US 20070000664 A1
Methods and apparatus for expanding a tubular with the aid of a compressive force are disclosed. A tubular is run into a wellbore. While the tubular is in a compressive state, the tubular is expanded into its desired form. The expanded tubular can be used for multiple downhole functions such as completing multilateral junctions in a wellbore, patching apertures in a wellbore and lining a wellbore.
1. A method of expanding a tubular in a wellbore, comprising:
positioning the tubular in the wellbore;
affixing at least first and second locations spaced along a length of the tubular to desired locations in the wellbore; and
expanding a portion of the tubular between the locations outward radially with a rotary expander tool, such that the tubular is in axial compression while expanding.
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9. A method of lining a drilled wellbore, comprising:
running a tubular into a wellbore;
applying a compressive force to at least a portion of the tubular; and
applying fluid pressure to an inside surface of the tubular in an area of the tubular that is in compression to expand the tubular to a larger diameter.
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18. An apparatus for wellbore completion, comprising:
a tubular coupled to a conveyance member;
one or more compression pistons for applying a compressive load to at least a length of the tubular; and
first and second seals for isolating an inside of the tubular corresponding to at least a portion of the length of the tubular having the compressive load applied thereto, wherein a port to the inside of the tubular supplies hydraulic pressure for acting on a inner surface of the tubular and expanding the tubular.
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22. A method of expanding a tubular in a wellbore, comprising:
positioning the tubular in the wellbore;
applying a compressive force to at least a portion of the tubular; and
expanding the portion of the tubular in compression outwardly, wherein expanding includes translating an expansion tool axially while the tubular is in compression.
1. Field of the Invention
Embodiments of the invention generally relate to expanding tubulars in a wellbore. More particularly, embodiments of the invention relate to the expansion of the tubulars enhanced by use of compressive forces applied to the tubulars.
2. Description of the Related Art
Hydrocarbon and other wells are completed by forming a borehole in the earth and then lining the borehole with pipe or casing to form a wellbore. After a section of wellbore is formed by drilling, a section of casing is lowered into the wellbore and temporarily hung therein from the surface of the well. Using apparatus known in the art, the casing is cemented into the wellbore by circulating cement into the annular area defined between the outer wall of the casing and the borehole. The combination of cement and casing strengthens the wellbore and facilitates the isolation of certain areas of the formation behind the casing for the production of hydrocarbons.
Recent developments in the oil and gas exploration and extraction industries have included using expandable bore lining tubing. Apparatus and methods are emerging that permit tubulars to be expanded in situ. The most common expansion apparatus is a cone or a swedge. Some expansion apparatus include expander tools which are fluid powered and are run into the wellbore on a working string. These hydraulic expander tools can include radially extendable members which, through fluid pressure, are urged outward radially from the body of the expander tool and into contact with a tubular therearound. As sufficient pressure is generated on a piston surface behind these extendable members, the tubular being acted upon by the expansion tool is expanded past its point of plastic deformation. In this manner, the inner and outer diameter of the tubular is increased in the wellbore. By rotating the expander tool in the wellbore and/or moving the expander tool axially in the wellbore with the extendable members actuated, a tubular can be expanded along a predetermined length in a wellbore. Other methods include using hydraulic pressure inside the tubular to expand the tubular past its point of plastic deformation.
Multiple uses for expandable tubulars are being discovered. For example, an intermediate string of casing can be hung off a string of surface casing by expanding a portion of the intermediate string into frictional contact with the lower portion of surface casing therearound. This allows for the hanging of a string of casing without the need for a separate slip assembly. Additional applications for the expansion of downhole tubulars exist. These include the use of an expandable sand screen, employment of an expandable seat for seating a diverter tool, and the use of an expandable seat for setting a packer.
There are problems associated with the expansion of tubulars. One particularly associated with rotary expander tools is that the rotary expansion of the tubular makes the wall of the tubular thinner. This then increases the overall length of the tubular which is problematic when trying to determine location in the well. Further, expandable tubulars are currently limited to an expansion of 10%-25% of their original diameter using existing expansion techniques that are constrained by the tubular burst pressure and friction applied thereto. Also when using hydraulic pressure to expand the tubular, due to the high pressure required, weaknesses in the tubular are exploited limiting the amount of expansion that can be achieved before the tubular ruptures.
There exists a need for an improved method and apparatus for expanding casing or other tubulars within a wellbore. Further, there exists a need for method and apparatus for expanding a tubular which requires less outward force or hydraulic pressure on the tubular with increased expansion. There exists yet a further need for an apparatus and method for expanding a tubular which reduces the risk of uneven expansion of the tubular by reducing the amount of force needed for the expansion operation. Further, there exists a need for a method of expanding a tubular and accurately controlling the location of the tubing.
Embodiments of the invention generally relate to methods and apparatus for expanding tubulars in a wellbore enhanced by compressive force applied to the tubulars. According to one aspect of the invention, a method of expanding a tubular in a wellbore includes positioning the tubular in the wellbore, affixing at least two locations spaced along a length the tubular to desired locations in the wellbore, and expanding a portion of the tubular between the two locations outward radially with a rotary expander tool, such that the tubular is in compression while expanding. According to another aspect of the invention, methods and apparatus provide for expanding a tubular run into a wellbore by applying a compressive force to at least a portion of the tubular and applying fluid pressure to an inside surface of the tubular to expand the tubular to a larger diameter. The tubular can be located proximate to a window in the wellbore such that expanding the compressed portion of the tubular covers the window and may form a bulge extending through the window.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIGS. 8 to 11 are schematic illustrations of steps in the process of lining a bore in accordance with embodiments of the invention.
U.S. Pat. No. 6,457,532, which is herein incorporated by reference in its entirety, discloses an exemplary rotary expander tool that can be used as the rotary expander tool 140 schematically illustrated in
Before both of the two fixed locations 120, 130 are set, the tubular 110 can optionally be placed in compression either through use of gravity or a mechanical, electrical, or hydraulic device adapted to apply a compressive load on the tubular. Since the tubular 110 is expanded between end points that are fixed, this increases accurate location of the tubular 110 in the wellbore 100. Thus, this process enables accurate placement of liners, patches and other tubulars in the wellbore without the side effects of having the liner elongate or shorten during expansion.
The expandable tubing 200 attaches to a work string 210 via a setting tool 220. The lower end of the expandable tubing 200 attaches to the work string 210 by a carrying mechanism 240 of the setting tool 220. The carrying mechanism 240 is any suitable temporary connection known in the art such as carrying dogs, collets, threads, latches, slips etc. In one embodiment the carrying mechanism 240 is a set of pre-set slips 231. The pre-set slips 231 engage the inside diameter of the expandable tubing 200 with a series of teeth 232. The pre-set slips 231 support the weight of the expandable tubing 200 and the piston assembly. The pre-set slips 231 are held in place by wedges 233 and 234. Wedge 234 is fixedly attached to the work string 210. Wedge 233 is attached to a slip release assembly 236. The slip release assembly 236 connects to a seat 237. The seat 237 holds a sealing member such as a dart, or ball 270 at its upper end in order to hydraulically seal the work string 210. The seat 237 connects to the work string 210 with a shear pin 238. Above the pre-set slips 231 is a lower pressure seal cup 239 for hydraulically sealing the interior of the expandable tubing 200. At the upper end of the expandable tubing 200, a compression piston 250 of the setting tool 220 attaches the expandable tubing 200 to the work string 210. The compression piston 250 has a shoulder 253 which engages the upper end of the expandable tubing 200. The compression piston 250 moves relative to the work string 210 and a piston base 251. The piston base 251 fixedly attaches to the work sting 210, thus as fluid flows in to an annulus 252, the piston 250 pushes the expandable tubular 200 down relative to the work string 210. With the lower end of the expandable tubular 200 fixed to the work string 210 by carrying mechanism 240, the expandable tubular 200 is in compression. More than one compression piston can be used in order to increase the compressive force applied to the expandable tubing 200, as is known in the art. The carrying mechanism 240 and the compression piston 250 can be adapted to seal the top and bottom of the expandable tubing 200.
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The expandable tubing 200 can utilize changes in material and configuration in order to enhance expansion. In one embodiment, the tubing thickness at the two fixed end points, the piston 250 and carrying mechanism 240 is larger that the expandable tubing 200 wall thickness between the fixed points. Further, in another embodiment the yield strength and/or elastic modulus of the expandable tubular 200 is changed between the fixed points. In another embodiment the expandable tubular 200 is longitudinally corrugated between the fixed points. In yet another embodiment the expandable tubular 200 has a different material than the material at the fixed points. Further, any of these methods can be used in combination to enhance expansion of the expandable tubular 200. These embodiments ensure the expandable tubular 200 expands from the middle portion first and then outwards toward both ends. This ensures that fluids are not trapped in the annulus between the Expandable tubular 200 and the liner 230.
After expansion of the expandable tubing 200 with hydraulic pressure it is necessary to ensure the expandable tubular 200 is secure in the wellbore by pulling or pushing on the work string 210. The setting tool 220 then releases the expandable tubular 200 at the carrying mechanism 240. By increasing the hydraulic pressure in the work string 210 the seat 237 shears the shear pin 238. This causes the slip release assembly 236 to move down which moves the lower wedge 233 down, releasing the pre-set slips 231 as shown in
An expandable tubing or liner 430 is run into the wellbore 400 on a work string 440. The liner 430 is initially coupled to the work string 440 via a setting tool 450. The liner 430 is located in the wellbore 400 such that the upper end of the liner 430 overlaps the larger diameter casing end section 425. The lower end of the liner 430 is positioned at the end of the wellbore 400. The liner 430 itself or a shoe 460 contacts the bottom of the wellbore 400. Next, weight can optionally be set down on the liner 430. The weight can be from the length of the work string 440, or any other method that places the liner 430 in a compressive state.
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Any of the expandable tubing described above can be longitudinally corrugated tubing or shaped pipe in order to further facilitate expansion. Using shaped pipe or corrugated tubing also reduces the tendency for pipe to buckle. This allows for compression of longer lengths of pipe enhancing the expansion process further.
Further, the methods described above can be used in any type of down hole tubular expansion including but not limited to liner hangers, packers, straddles, PBRs, drilling-with-liner, etc.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.