1. Field of the Invention
Embodiments of the present invention generally relate to a downhole expansion assembly. More particularly, embodiments of the present invention relate to seals for the downhole expansion assembly.
2. Description of the Related Art
In the oilfield industry, downhole tools are employed in the wellbore at different stages of operation of the well. For example, an expandable liner hanger may be employed during the formation stage of the well. After a first string of casing is set in the wellbore, the well is drilled a designated depth and a liner assembly is run into the well to a depth whereby the upper portion of the liner assembly is overlapping a lower portion of the first string of casing. The liner assembly is fixed in the wellbore by expanding a liner hanger into the surrounding casing and then cementing the liner assembly in the well. The liner hanger includes seal members disposed on an outer surface of the liner hanger. The seal members are configured to create a seal with the surrounding casing upon expansion of the liner hanger.
In another example, a packer may be employed during the production stage of the well. The packer typically includes a packer assembly with seal members. The packer may seal an annulus formed between production tubing disposed within casing of the wellbore. Alternatively, some packers seal an annulus between the outside of a tubular and an unlined borehole. Routine uses of packers include the protection of casing from pressure, both well and stimulation pressures, and protection of the wellbore casing from corrosive fluids. Packers may also be used to hold kill fluids or treating fluids in the casing annulus.
Both the liner hanger and the packer include seal members that are configured to create a seal with the surrounding casing or an unlined borehole. Each seal member is typically disposed in a groove (or gland) formed in an expandable tubular assembly of the liner hanger or packer. However, the seal member may extrude out of the groove during expansion of the expandable tubular assembly due to the characteristics of the seal member. Further, the seal member may extrude out of the groove after expansion of the expandable tubular assembly due to pressure differentials applied to the seal member. Therefore, there is a need for extrusion-resistant seals for use with an expandable tubular assembly.
The present invention generally relates to an anchor seal for an expandable tubular assembly. In one aspect, an anchoring seal assembly for creating a seal portion and an anchor portion between a first tubular that is disposed within a second tubular is provided. The anchoring seal assembly includes an expandable annular member attached to the first tubular. The annular member has an outer surface and an inner surface. The anchoring seal assembly further includes a seal member disposed in a groove formed in the outer surface of the expandable annular member. The seal member has one or more anti-extrusion spring bands embedded within the seal member, wherein the outer surface of the expandable annular member adjacent the groove includes a rough surface. The anchoring seal assembly also includes an expander sleeve having a tapered outer surface and an inner bore. The expander sleeve is movable between a first position in which the expander sleeve is disposed outside of the expandable annular member and a second position in which the expander sleeve is disposed inside of the expandable annular member, wherein the expander sleeve is configured to radially expand the expandable annular member into contact with an inner wall of the second tubular to create the seal portion and the anchor portion as the expander sleeve moves from the first position to the second position.
In another aspect, a method of creating a seal portion and an anchor portion between a first tubular and a second tubular is provided. The method includes the step of positioning the first tubular within the second tubular. The first tubular has an annular member with a groove and a rough outer surface, wherein a seal member with at least one anti-extrusion band is disposed within the groove and wherein a gap is formed between a side of the seal member and a side of the groove. The method further includes the step of expanding the annular member radially outward, which causes the at least one anti-extrusion band to move toward an interface area between the first tubular and the second tubular. The method also includes the step of urging the annular member into contact with an inner wall of the second tubular to create the seal portion and the anchor portion between the first tubular and the second tubular.
In another aspect, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface of the annular member. The seal assembly further includes a seal member disposed in the groove, the seal member having one or more anti-extrusion bands. The seal member is configured to be expandable radially outward into contact with an inner wall of the second tubular by the application of an outwardly directed force supplied to an inner surface of the annular member. Additionally, the seal assembly includes a gap defined between the seal member and a side of the groove.
In another aspect, a method of creating a seal between a first tubular and a second tubular is provided. The method includes the step of positioning the first tubular within the second tubular, the first tubular having a annular member with a groove, wherein a seal member with at least one anti-extrusion band is disposed within the groove and wherein a gap is formed between a side of the seal member and a side of the groove. The method further includes the step of expanding the annular member radially outward, which causes the first anti-extrusion band and the second anti-extrusion band to move toward a first interface area and a second interface area between the annular member and the second tubular. The method also includes the step of urging the seal member into contact with an inner wall of the second tubular to create the seal between the first tubular and the second tubular.
In yet another aspect, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface thereof. The seal assembly further includes a seal member disposed in the groove of the annular member such that a side of the seal member is spaced apart from a side of the groove, the seal member having one or more anti-extrusion bands, wherein the one or more anti-extrusion bands move toward an interface area between the annular member and the second tubular upon expansion of the annular member.
In a further aspect, a hanger assembly is provided. The hanger assembly includes an expandable annular member having an outer surface and an inner surface. The hanger assembly further includes a seal member disposed in a groove formed in the outer surface of the expandable annular member, the seal member having one or more anti-extrusion spring bands embedded within the seal member. The hanger assembly also includes an expander sleeve having a tapered outer surface and an inner bore. The expander sleeve is movable between a first position in which the expander sleeve is disposed outside of the expandable annular member and a second position in which the expander sleeve is disposed inside of the expandable annular member. The expander sleeve is configured to radially expand the expandable annular member as the expander sleeve moves from the first position to the second position.
In a further aspect, a downhole tool for use in a wellbore is provided. The tool includes a body having a bore. The tool further includes a seal assembly attached to the body. The seal assembly having an expandable annular member, a seal member and an expander sleeve, wherein the seal member includes one or more anti-extrusion spring bands embedded within the seal member. The tool further includes a slip assembly attached to the body. The slip assembly includes slips that are configured to engage the wellbore.
In a further aspect, downhole tool for use in a wellbore is provided. The tool includes a tubular having a tapered outer surface. The tool further includes an expandable annular member disposed on the tubular. The expandable member has an anchor portion. The tool further includes a seal member disposed in a groove of the expandable annular member. The seal member has one or more anti-extrusion bands, wherein the seal member and the anchor portion are configured to be expandable radially outward into contact with the wellbore as the expandable annular member moves along the tapered outer surface of the tubular.
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, some of 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. The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
The present invention generally relates to extrusion-resistant seals for a downhole tool. The extrusion-resistant seals will be described herein in relation to a liner hanger in
The liner assembly 110 includes a tubular 165 and the expandable hanger 100 of this present invention. The hanger 100 is an annular member that is used to attach or hang the tubular 165 from an internal wall of the casing 60. The expandable hanger 100 includes a plurality of seal assemblies 150 disposed on the outer surface of the hanger 100. The plurality of seal assemblies 150 are circumferentially spaced around the hanger 100 to create a seal between liner assembly 110 and the casing 60 upon expansion of the hanger 100. Although the hanger 100 in
As shown in
Referring back to
As shown in
The seal ring 135 changes configuration during the expansion operation. As shown in
The volume of the gland 140 and/or the volume gap 145 may decrease as the seal assembly 150 is expanded radially outward during the expansion operation. As set forth herein, the angle α (
As shown in
There are several benefits of the extrusion barrier created by the seal bands 155, 160. One benefit of the extrusion barrier would be that the outer surface of the seal ring 135 in contact with the casing 60 is limited to a region between the seal bands 155, 160, which allows for a high-pressure seal to be created between the seal assembly 150 and the casing 60. In one embodiment, the seal assembly 150 may create a high-pressure seal in the range of 12,000 to 14,000 psi. A further benefit of the extrusion barrier would be that the seal assembly 150 is capable of creating a seal with a surrounding casing that may have a range of inner diameters due to API tolerances. Another benefit would be that the extrusion barrier created by the seal bands 155, 160 may prevent erosion of the seal ring 135 after the hanger 100 has been expanded. The erosion of the seal ring 135 could eventually lead to a malfunction of the seal assembly 150. A further benefit is that the seal bands 155, 160 act as an extrusion barrier after expansion of the expandable hanger 100. More specifically, the extrusion barrier created by the seal bands 155, 160 may prevent extrusion of the seal ring 135 when the gap between the expandable hanger 100 and the casing 60 is increased due to downhole pressure. In other words, the seal bands 155, 160 bridge the gap, and the net extrusion gap between coils of the seal bands 155, 160 grows considerably less as compared to an annular gap that is formed when a seal ring does not include the seal bands. For instance, the annular gap (without seal bands) may be on the order of 0.030″ radial as compared to the net extrusion gap between coils of the seal bands 155, 160 which may be on the order of 0.001/0.003″.
The tubing string 50 also carries a downhole tool 300, such as a packer, a bridge plug or any other downhole tool used to seal a desired location in a wellbore. Although generically shown as a singular element, the downhole tool 300 may be an assembly of components. Generally, the downhole tool 300 may be operated by hydraulic or mechanical means and is used to form a seal at a desired location in the wellbore 25. The downhole tool 300 may seal, for example, an annular space 20 formed between a production tubing 50 and the wellbore casing 106. Alternatively, the downhole tool 300 may seal an annular space between the outside of a tubular and an unlined wellbore. Common uses of the downhole tool 300 include protection of the casing 10 from pressure and corrosive fluids; isolation of casing leaks, squeezed perforations, or multiple producing intervals; and holding of treating fluids, heavy fluids or kill fluids. However, these uses for the downhole tool 300 are merely illustrative, and application of the downhole tool 300 is not limited to only these uses. The downhole tool 300 may also be used with a conventional liner hanger (not shown) in a liner assembly. Typically, the downhole tool 300 would be positioned in the liner assembly proximate the conventional liner hanger. In one embodiment, the downhole tool assembly is positioned above the conventional liner hanger. After the conventional liner hanger is set inside the wellbore casing, a cementation operation may be done to secure the liner within the wellbore. Thereafter, the downhole tool 300 may be activated to seal an annular space formed between liner assembly and the wellbore casing.
The downhole tool 300 includes a locking mechanism which allows the wedge member 325 to travel in one direction and prevents travel in the opposite direction. In one embodiment, the locking mechanism is implemented as a ratchet ring 380 disposed on a ratchet surface 385 of the mandrel 305. The ratchet ring 380 is recessed into, and carried by, the wedge member 325. In this case, the interface of the ratchet ring 380 and the ratchet surface 385 allows the wedge member 325 to travel only in the direction of the arrow 315.
A portion of the wedge member 325 forms an outer tapered surface 375. In operation, the tapered surface 375 forms an inclined glide surface for a packing element 400. Accordingly, the wedge member 325 is shown disposed between the mandrel 305 and packing element 400, where the packing element 400 is disposed on the tapered surface 375. In the depicted run-in position, the packing element 400 is located at a tip of the wedge member 325, the tip defining a relatively smaller outer diameter with respect to the other end of the tapered surface 375.
The packing element 400 is held in place by a retaining sleeve 320. The packing element 400 may be coupled to the retaining sleeve 320 by a variety of locking interfaces. In one embodiment, the retaining sleeve 320 includes a plurality of collet fingers 355. The terminal ends of the collet fingers 355 are interlocked with an annular lip 405 of the packing element 400. The collet fingers 355 may be biased in a radial direction. For example, it is contemplated that the collet fingers 355 have outward radial bias urging the collet fingers 355 into a flared or straighter position. However, in this case the collet fingers 355 do not provide a sufficient force to cause expansion of the packing element 400.
The downhole tool 300 includes a self-adjusting locking mechanism which allows the retaining sleeve 320 to travel in one direction and prevents travel in the opposite direction. The locking mechanism is implemented as a ratchet ring 390 disposed on a ratchet surface 395 of the mandrel 305. The ratchet ring 390 is recessed into, and carried by, the retaining sleeve 320. In this case, the interface of the ratchet ring 390 and the ratchet surface 395 allows the retaining sleeve 320 to travel only in the direction of the arrow 330, relative to the mandrel 305. As will be described in more detail below, this self-adjusting locking mechanism ensures that a sufficient seal is maintained by the packing element 400 despite counter-forces acting to subvert the integrity of the seal.
In operation, the downhole tool 300 is run into a wellbore in the run-in position shown in
In the set position, the collet fingers 355 are flared radially outwardly but remain interlocked with the lip 405 formed on the packing element 400. This coupling ties the position of the retaining sleeve 320 and ratchet ring 390 to the axial position of packing element 400. This allows the packing element 400 to move up the wedge member 325 in response to increased pressure from below, maintaining its tight interface with the casing inner diameter, but prevents relative movement of the packing element 400 in the opposite direction (shown by the arrow 315). The pressure from below the downhole tool 300 may act to diminish the integrity of the seal formed by the packing element 400 since the interface of the packing element 400 with the casing 10 and wedge member 325 will loosen due to pressure swelling the casing 10 and likewise acting to collapse the wedge member 325 from under the packing element 400. One embodiment of the downhole tool 300 counteracts such an undesirable effect by the provision of the self-adjusting locking mechanism implemented by the ratchet ring 390 and ratchet surface 395. In particular, the retaining sleeve 320 is permitted to travel up the mandrel 305 in the direction of the arrow 330 in response to a motivating force acting on the packing element 400, as shown in
To form a seal with respect to the casing 10, the packing element 400 includes one or more sealing elements 450A-B. The sealing elements 450A-B may be elastomer bands. In another embodiment, the sealing elements 450A-B are swelling elastomers. The sealing elements 450A-B are preferably secured in grooves 455A-B formed in the tubular body 440. For example, the sealing elements 450A-B may be bonded to the grooves 455A-B by a bonding material during the fabrication stage of the packing element 400. Each groove 455A-B includes a volume gap 470A-B. As shown in
Each sealing element 450A-B includes a first seal band 460 and a second seal band 465. The seal bands 460, 465 are embedded in the sealing element 450A-B. In one embodiment, the seal bands 460, 465 are springs. The seal bands 460, 465 are used to limit the extrusion of the sealing element 450A-B upon expansion of the packing element 400.
The portions of the outer surface between the sealing elements 450A-B form non-elastomer sealing surfaces 430A-C. The non-elastomer sealing surfaces 430A-C may include grip members, such as carbide inserts, knurling or a rough surface which allows the non-elastomer sealing surfaces 430A-C to seal and act as an anchor upon expansion of the packing element 400. For instance, the anchor portion (i.e., rough surface on the surfaces 430A-C) would contact and engage with the surrounding casing 10 when the packing element 400 is set, as shown in
The anchor portion (i.e., rough surface on the surfaces 430A-C) may be used in place of a gripping member (not shown) in the downhole tool 300. Rather than having a separate gripping member, such as slips, on the downhole tool 300, the anchor portion may be configured to hold the downhole tool 300 within the casing 10, thus reducing the number of components in the downhole tool 300 and reducing the overall length of the downhole tool 300. Other benefits of using the anchor portion (rather than separate slips) would be that the overall stroke length of the downhole tool 300 would be reduced; elimination of potential leak paths and manufacturing costs would be reduced without compromising performance. The length and/or the size of the surfaces 430A-C may be arranged such that when the packing element 400 is set, a sufficient gripping force is created between the anchor portion and the surrounding casing 10 to support the downhole tool 300 within the wellbore. The surfaces 430A-C may also be induction hardened so that the surfaces 430A-C penetrate the casing 10 surface to provide a robust anchoring means upon activation of the packing element 400. As discussed herein in relation to
The number and size of the sealing elements 450A-B define the surface area of the non-elastomer sealing surfaces 430A-C. It is to be noted that any number of sealing elements 450A-B and non-elastomer sealing surfaces 430A-C may be provided. The packing element 400 shown includes two sealing elements 450A-B and defining three non-elastomer sealing surfaces 430A-C. In general, a relatively narrow width of each non-elastomer sealing surface 430A-C is preferred in order to achieve a sufficient contact force between the surfaces and the casing 10.
The shaped inner diameter of the tubular body 440 is defined by a plurality of ribs 475 separated by a plurality of cutouts 480 (e.g., voids). The cutouts 480 allow a degree of deformation of the tubular body 440 when the packing element 400 is placed into a sealed position. Further, the cutouts 480 aid in reducing the amount of setting force required to expand the packing element 400 into the sealed position. In other words, by removing material (e.g., cutouts 480) of the tubular body 440, the force required to expand the packing element 400 is reduced. In one embodiment, the volume of the cutouts 480 (voids) is between 25-40% of the volume of the tubular body 440. The ribs 475 are annular members integrally formed as part of the tubular body 440. Each rib 475 forms an actuator-contact surface 485 at the inner diameter of the tubular body 340, where the rib 475 is disposed on the tapered surface 375. In an illustrative embodiment, the tapered surface 375 has an angle γ between about 2 degrees and about 6 degrees. Accordingly, the shaped inner diameter defined by the actuator-contact surfaces 485 may have a substantially similar taper angle.
The tubular body 440 further includes an O-ring seal 495 in cutout 490. The seal 495 is configured to form a fluid-tight seal with respect to the outer tapered surface 375 of the wedge member 325. In one embodiment, the seal 495 includes seal bands (i.e., anti-extrusion bands) in a similar manner as sealing element 450A-B. Further, a volume gap may be defined between the seal 495 and a portion of the cutout 490 in a similar manner as volume gap 470A-B. It is noted that in another embodiment, the cutouts 480 may also, or alternatively, carry seals at their respective inner diameters.
In
During the expansion operation, the seal bands 460, 465 in the sealing element 450A-B are urged toward an interface 415 between the packing element 400 and the casing 10, as shown in
The seal bands 460, 465 are configured to substantially prevent the extrusion of the sealing element 450A-B past the interface 415. In other words, the seal bands 460, 465 expand radially outward with the packing element 400 and block the elastomeric material of the sealing element 450A-B from flowing through the interface 415 between the packing element 400 and the casing 10. In one embodiment, the seal bands 460, 465 are springs, such as toroidal coil springs, which expand radially outward due to the expansion of the packing element 400. As the spring expands radially outward during the expansion operation, the coils of spring act as a barrier to the flow of the elastomeric material of the sealing element 450A-B. After the expansion operation, the seal bands 460, 465 may prevent extrusion of the sealing element 450A-B when a gap between the packing element 400 and the casing 10 is increased due to downhole pressure. In other words, the seal bands 460, 465 bridge the gap between the packing element 400 and the casing 10 and prevent extrusion of the sealing element 450A-B. In this manner, the seal bands 460, 465 in the sealing element 450A-B act as an anti-extrusion device or an extrusion barrier during the expansion operation and after the expansion operation.
There are several benefits of the extrusion barrier created by the seal bands 460, 465. One benefit of the extrusion barrier would be that the outer surface of the sealing element 450A-B in contact with the casing 10 is limited to a region between the seal bands 460, 465, which allows for a high pressure seal to be created between the packing element 400 and the casing 10. In one embodiment, the packing element 400 may create a high-pressure seal in the range of 12,000 to 15,000 psi. A further benefit of the extrusion barrier would be that the packing element 400 is capable of creating a seal with a surrounding casing that may have a range of inner diameters due to API tolerances. Another benefit would be that the extrusion barrier created by the seal bands 460, 465 may prevent erosion of the sealing element 450A-B after the packing element 400 has been expanded. The erosion of the sealing element 450A-B could eventually lead to a malfunction of the packing element 400.
The packing element 400 rests at the diametrically enlarged end of the tapered surface 375 and is sandwiched between the wedge member 325 and the casing 10. The dimensions of the downhole tool 300 are preferably such that the packing element 400 is fully engaged with the casing 10, before the tubular body 440 reaches the end of the tapered surface 375. Note that in the sealed position, the sealing elements 450A-B and the non-elastomer sealing surfaces 430A-C have been expanded into contact with the casing 10.
As such, it is clear that the tubular body 440 has undergone a degree of deformation. The process of deformation may occur, at least in part, as the packing element 400 slides up the tapered surface 375, prior to making contact with the inner diameter of the casing 10. Additionally or alternatively, deformation may occur as a result of contact with the inner diameter of the casing 106. In any case, the process of deformation causes the sealing elements 450A-B and the non-elastomer sealing surfaces 430A-C to contact the inner diameter of the casing 10 in the sealed position. In addition, the non-elastomeric backup seals prevent extrusion of the sealing elements 450A-B.
The hanger assembly 500 includes the hanger 530 of this present invention. The hanger 530 may be used to attach or hang liners from an internal wall of the casing 80. The hanger 530 may also be used as a patch to seal an annular space formed between hanger assembly 500 and the wellbore casing 80 or an annular space between hanger assembly 500 and an unlined wellbore. The hanger 530 optionally includes grip members, such as tungsten carbide inserts or slips. The grip members may be disposed on an outer surface of the hanger 530. The grip members may be used to grip an inner surface of the casing 80 upon expansion of the hanger 530.
As shown in
The side of the gland 540 creates a volume gap 545 between the seal ring 535 and the gland 540. As set forth herein, the volume gap 545 is generally used to minimize distortion of the seal ring 535 upon expansion of the hanger 530. The volume gap 545 may be created in any configuration (see
The hanger assembly 500 includes the expander sleeve 510 which is used to expand the hanger 530. In one embodiment, the expander sleeve 510 is attached to the hanger 530 by an optional releasable connection member 520, such as a shear pin. The expander sleeve 510 includes a tapered outer surface 515 and a bore 525. The expander sleeve 510 further includes an end portion 505 that is configured to interact with an actuator member (not shown). The expander sleeve 510 optionally includes a self-adjusting locking mechanism (not shown) which allows the expander sleeve 510 to travel in one direction and prevents travel in the opposite direction.
To set the hanger assembly 500, the actuator member is driven axially in a direction toward the hanger 530. The axial movement of the actuator member may be caused by, for example, applied mechanical force from the weight of a tubing string or hydraulic pressure acting on a piston. The actuator member, in turn, engages the end portion 505 of the expander sleeve 510 in order to move the expander sleeve 510 axially toward the hanger 530. At a predetermined force, the optional releasable connection member 520 is disengaged, which allows the expander sleeve 510 to move relative to the hanger 530. The hanger 530 is prevented from moving with respect to the wedge expander sleeve 510. As the tapered outer surface 515 of expander sleeve 510 engages the inner surface of the hanger 530, the hanger 530 is moved into a diametrically expanded position.
The set position of the hanger assembly 500 is shown in
As shown in
As shown in
As mentioned herein, the packing element 400 may be used with different downhole tools. For instance, the packing element 400 may be used as a back-up for a compression or inflatable element, or in conjunction with a stage tool, or integral with a pack-off stage tool.
As shown in
In another embodiment, an anchor portion (i.e., rough surface on the surfaces 430A-C on the packing element 400) may be used in place of the slips 705 to support the stage tool 700 in the wellbore 75, thus reducing the number of components in the stage tool 700 and reducing the overall length of the stage tool 700. As set forth herein, the length and/or the size of the surfaces 430A-C may be arranged such that when the packing element 400 is set, a sufficient gripping force is created between the anchor portion and the surrounding wellbore 75 to support the downhole tool 300 within the wellbore 75. The surfaces 430A-C may also be induction hardened so that the surfaces 430A-C penetrate the surface of the wellbore 75 to provide a robust anchoring means upon activation of the packing element 400.
As shown in
After the ports 745, 750 are aligned, fluid in the bore 765 may flow through the ports 745, 750 into a fluid passageway 770 to set the packing element 400 and the slips 705. The fluid moving through the fluid passageway 770 generates a fluid pressure which causes the mechanical piston assembly 725 to apply a force on the wedge member 325 which is subsequently applied to the retaining sleeve 320. The force on the retaining sleeve 325 causes shear pin 785 to break and allows the slips 705 to move along the gauge ring 755. The movement of the slips 705 in a first direction relative to the gauge ring 755 causes the slips 705 to move radially outward and engage the wellbore 75, as shown in
The packing element 400 may be configured such that a force of a preselected magnitude is required in order to radially expand it during the packer setting process. This radial expansion is effected by the axial movement of wedge member 325 with respect to the packing element 400. Therefore, because of the angle of inclination of the wedge member 325 and friction between the wedge member 325 and packing element 400, the radial force required to radially expand packing element 400 can be correlated to a corresponding axial force which must be applied to the wedge member 325 in order to achieve relative movement between wedge member 325 and packing element 400. Hence, there exists a threshold axial force which must be applied to the wedge member 325 in order to radially expand packing element 400.
In operation, an axial force may be applied to the wedge member 325 (and therefore onto the packing element 400) which is less than this threshold axial force. In such instances, the applied axial force is communicated from the wedge member 325 to the packing element 400, and from the packing element 400 to collet fingers 355, and the retaining sleeve 320 without the packing element 805 experiencing any radial expansion (or any substantial radial expansion). Therefore, such an applied axial force less than the threshold axial force may be applied through the packing element 400 in order to effect the operation of another tool and/or another part of the same tool, such as setting slips 705 as described herein.
Furthermore, in operation, an axial force may be applied to the wedge member 325 (and therefore onto the packing element 400) which is greater than the aforementioned threshold axial force. In such instances, if there exists little or no available space for the packing element 400, collet fingers 355, and the retaining sleeve 320 to move axially, then the wedge member 325 may move axially with respect to the packing element 400. In this way, the wedge member 325 is forced further under the packing element 400, resulting in radial expansion of the packing element 400, which may continue until the packing element 400 has been moved to its set position in the wellbore.
In another embodiment, the aforementioned threshold axial force may be preselected by including a latch and/or a shearable fastening between the wedge member 325 and the packing element 400. This threshold axial force may be preselected by the configuration and (for example) selection of construction materials of the packing element 400 alone, or in combination with the configuration and selection of a suitable latch and/or shearable fastening between the wedge member 325 and the packing element 400.
In practice, by way of example, the aforementioned threshold axial force may be circa 10,000 lbs, though other magnitudes above and below this figure are contemplated, and may be tailored to suit specific applications.
The slip assembly 850 includes slips 840 and a wedge member 845. The wedge member 845 is generally cylindrical and slidably disposed about the mandrel 305. The downhole tool 800 includes a locking mechanism which allows the wedge member 845 to travel in one direction (arrow 865) and prevents travel in the opposite direction (arrow 870). In one embodiment, the locking mechanism is implemented as a ratchet ring 390 is disposed on a ratchet surface 395 of the mandrel 305. The ratchet ring 390 is recessed into, and carried by, the sleeve 320. In this case, the interface of the ratchet ring 390 and the ratchet surface 395 allows the sleeve 320 and the wedge member 845 to travel only in the direction as indicated by arrow 865. As shown, the sleeve 320 is attached to the wedge member 845 by a dog 890, and the sleeve is attached to the mandrel 305 by a shear pin 875.
The packing element 805 includes a tubular body 440, which is an annular member. The tubular body 440 includes an optional grip member 810 with a grip surface 815. The grip member 810 is configured to engage the casing 10 upon activation of the packing element 805. In a similar manner as described herein, the wedge member 325 is configured to move axially along the outer surface of the mandrel 305. The packing element 805 is prevented from moving with respect to the wedge member 325. As a result, the packing element 805 is forced to slide over the tapered surface of the wedge member 325. The positive inclination of the tapered surface urges the packing element 805 into a diametrically expanded position.
The packing element 805 may be configured such that a force of a preselected magnitude is required in order to radially expand it during the packer setting process. This radial expansion is effected by the axial movement of wedge member 325 with respect to the packing element 805. Therefore, because of the angle of inclination of the wedge member 325 and friction between the wedge member 325 and packing element 805, the radial force required to radially expand packing element 805 can be correlated to a corresponding axial force which must be applied to the wedge member 325 in order to achieve relative movement between wedge member 325 and packing element 805. Hence, there exists a threshold axial force which must be applied to the wedge member 325 in order to radially expand packing element 805.
In operation, an axial force may be applied to the wedge member 325 (and therefore onto the packing element 805) which is less than this threshold axial force. In such instances, the applied axial force is communicated from the wedge member 325 to the packing element 805, and from the packing element 805 to collet fingers 355, and retaining sleeve 320 without the packing element 805 experiencing any radial expansion (or any substantial radial expansion). Therefore, such an applied axial force less than the threshold axial force may be applied through the packing element 805 in order to effect the operation of another tool and/or another part of the same tool, such as setting slips 840 as described hereafter.
Furthermore, in operation, an axial force may be applied to the wedge member 325 (and therefore onto the packing element 805) which is greater than the aforementioned threshold axial force. In such instances, if there exists little or no available space for the packing element 805, collet fingers 355, and retaining sleeve 320 to move axially, then the wedge member 325 may move axially with respect to the packing element 805. In this way, the wedge member 325 is forced further under the packing element 805, resulting in radial expansion of the packing element 805, which may continue until the packing element 805 has been moved to its set position in the wellbore.
In another embodiment, the aforementioned threshold axial force may be preselected by including a latch and/or a shearable fastening between the wedge member 325 and the packing element 805. This threshold axial force may be preselected by the configuration and (for example) selection of construction materials of the packing element 805 alone, or in combination with the configuration and selection of a suitable latch and/or shearable fastening between the wedge member 325 and the packing element 805.
In practice, by way of example, the aforementioned threshold axial force may be circa 10,000 lbs, though other magnitudes above and below this figure are contemplated, and may be tailored to suit specific applications.
To set the slip assembly 850, an actuator sleeve (not shown) is driven axially in the direction of arrow 865. The axial movement of the actuator sleeve may be caused by, for example, applied mechanical force from the weight of a tubing string or hydraulic pressure acting on a piston. The actuator sleeve applies a force on the wedge member 325, which drives the wedge member 325 axially along the outer surface of the mandrel 305. The movement of the sleeve 320 along the outer surface of the mandrel 305 toward the wedge member 845 causes the shear pin 875 to break. Thereafter, the sleeve 320 moves along the mandrel 305 thereby allowing the dog 890 to be released. The sleeve 320 moves until a surface 880 of the sleeve 320 contacts an end surface 885 of the wedge member 845 (compare
The packing element 905 includes the tubular body 440, which is an annular member. The tubular body 440 has an anchor 910 with a grip surface 915. The anchor 910 is configured to engage the casing 10 upon activation of the packing element 905. The anchor 910 may be used in place of a gripping member (not shown) in the downhole tool 900. Rather than having a separate gripping member, such as slips, on the downhole tool 900, the anchor 910 may be configured to hold the downhole tool 900 within the casing 10, thus reducing the number of components in the downhole tool 900 and reducing the overall length of the downhole tool 900. Other benefits of using the anchor 910 (rather than separate slips) would be that the overall stroke length of the downhole tool 900 would be reduced; elimination of potential leak paths and manufacturing costs would be reduced without compromising performance. The length and/or the size of the grip surface 915 may be arranged such that when the packing element 905 is set, a sufficient gripping force is created between the anchor 910 and the surrounding casing 10 to support the downhole tool 900 within the wellbore.
The downhole tool 900 includes a self-adjusting locking mechanism which allows the retaining sleeve 320 to travel in one direction and prevents travel in the opposite direction. The locking mechanism is implemented as a ratchet ring 390 disposed on a ratchet surface 395 of a mandrel 950. The ratchet ring 390 is recessed into, and carried by, the retaining sleeve 320. In this case, the interface of the ratchet ring 390 and the ratchet surface 395 allows the retaining sleeve 320 to travel only in the direction of the arrow 965, relative to the mandrel 950.
As shown in
In the set position, the packing element 905 is urged into contact with the casing 10 to form a fluid-tight seal and the gripping surface 915 of the anchor 910 engages the casing 10. The anchor 910 may be used to support the tool 900 in the casing 10. Additionally, the anchor 910 may be used to hold the packing sealing elements 450A-B in place by preventing movement of the packing element 905. More specifically, the anchor 910 ensures that the packing sealing elements 450A-B do not move with respect to the casing 10 when subjected to high differential pressure, thus allowing the packing sealing elements 450A-B to maintain the sealing relationship with the casing 10, while at the same time reducing wear on the packing element 905. In one embodiment, the gripping surface 915 of the anchor 910 is induction hardened or similar means so that the gripping surface 915 penetrates an inner surface of the casing 10 to provide a robust anchoring means when the packing element 905 is activated. In this manner, the anchor 910 may be used to support the tool 900 within the casing 10 and also help resist axial movement of the packing sealing elements 450A-B relative to the casing 10 when the packing sealing elements 450A-B are subjected to high differential pressure.
In one embodiment, an anchoring seal assembly for creating a seal portion and an anchor portion between a first tubular that is disposed within a second tubular is provided. The anchoring seal assembly includes an expandable annular member attached to the first tubular. The annular member has an outer surface and an inner surface. The anchoring seal assembly further includes a seal member disposed in a groove formed in the outer surface of the expandable annular member. The seal member has one or more anti-extrusion spring bands embedded within the seal member, wherein the outer surface of the expandable annular member adjacent the groove includes a rough surface. The anchoring seal assembly also includes an expander sleeve having a tapered outer surface and an inner bore. The expander sleeve is movable between a first position in which the expander sleeve is disposed outside of the expandable annular member and a second position in which the expander sleeve is disposed inside of the expandable annular member, wherein the expander sleeve is configured to radially expand the expandable annular member into contact with an inner wall of the second tubular to create the seal portion and the anchor portion as the expander sleeve moves from the first position to the second position.
In another embodiment, a method of creating a seal portion and an anchor portion between a first tubular and a second tubular is provided. The method includes the step of positioning the first tubular within the second tubular. The first tubular has an annular member with a groove and a rough outer surface, wherein a seal member with at least one anti-extrusion band is disposed within the groove and wherein a gap is formed between a side of the seal member and a side of the groove. The method further includes the step of expanding the annular member radially outward, which causes the at least one anti-extrusion band to move toward an interface area between the first tubular and the second tubular. The method also includes the step of urging the annular member into contact with an inner wall of the second tubular to create the seal portion and the anchor portion between the first tubular and the second tubular.
In one embodiment, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface of the annular member. The seal assembly further includes a seal member disposed in the groove, the seal member having one or more anti-extrusion bands. The seal member is configured to be expandable radially outward into contact with an inner wall of the second tubular by the application of an outwardly directed force supplied to an inner surface of the annular member. Additionally, the seal assembly includes a gap defined between the seal member and a side of the groove.
In one aspect, the gap is configured to close upon expansion of the annular member. In another aspect, the gap is configured to close completely upon expansion of the annular member. In a further aspect, a portion of the seal member is used to close the gap. In an additional aspect, the one or more anti-extrusion bands comprise a first anti-extrusion band and a second anti-extrusion band. In yet a further aspect, the first anti-extrusion member is embedded on a first side of the seal member and the second anti-extrusion band is embedded on a second side of the seal member. In another aspect, the first anti-extrusion band and the second anti-extrusion band are springs. In a further aspect, the first anti-extrusion band and the second anti-extrusion band are configured to move toward a first interface area and a second interface area between the annular member and the second tubular upon expansion of the annular member. In an additional aspect, the first interface area is adjacent a first side of the groove and the second interface area is adjacent a second side of the groove.
In one aspect, the seal member is configured to move into the gap upon expansion of the seal member. In another aspect, a second gap is defined between the seal member and another side of the groove. In a further aspect, a biasing member disposed within the gap. In an additional aspect, a plurality of cutouts formed on an inner surface of the annular member. In another aspect, the annular member is a liner hanger. In yet a further aspect, the annular member is a packer.
In another embodiment, a method of creating a seal between a first tubular and a second tubular is provided. The method includes the step of positioning the first tubular within the second tubular, the first tubular having a annular member with a groove, wherein a seal member with at least one anti-extrusion band is disposed within the groove and wherein a gap is formed between a side of the seal member and a side of the groove. The method further includes the step of expanding the annular member radially outward, which causes the first anti-extrusion band and the second anti-extrusion band to move toward a first interface area and a second interface area between the annular member and the second tubular. The method also includes the step of urging the seal member into contact with an inner wall of the second tubular to create the seal between the first tubular and the second tubular.
In one aspect, the gap is closed between the seal member and the groove upon expansion of the annular member. In another aspect, the gap is closed by filling the gap with a portion of the seal member. In a further aspect, an expander tool is urged into the annular member to expand the annular member radially outward. In an additional aspect, the expander tool is removed from the annular member after the expansion operation. In yet another aspect, the expander tool remains within the annular member after the expansion operation.
In yet another embodiment, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface thereof. The seal assembly further includes a seal member disposed in the groove of the annular member such that a side of the seal member is spaced apart from a side of the groove, the seal member having one or more anti-extrusion bands, wherein the one or more anti-extrusion bands move toward an interface area between the annular member and the second tubular upon expansion of the annular member.
In one aspect, the one or more anti-extrusion bands comprise a first anti-extrusion band and a second anti-extrusion band. In another aspect, the first anti-extrusion band and the second anti-extrusion band are configured to move into an annular gap formed between the annular member and the second tubular after expansion of the annular member due to downhole pressure. In a further aspect, at least one side of the seal member is attached to the groove via glue.
In a further embodiment, a hanger assembly is provided. The hanger assembly includes an expandable annular member having an outer surface and an inner surface. The hanger assembly further includes a seal member disposed in a groove formed in the outer surface of the expandable annular member, the seal member having one or more anti-extrusion spring bands embedded within the seal member. The hanger assembly also includes an expander sleeve having a tapered outer surface and an inner bore. The expander sleeve is movable between a first position in which the expander sleeve is disposed outside of the expandable annular member and a second position in which the expander sleeve is disposed inside of the expandable annular member. The expander sleeve is configured to radially expand the expandable annular member as the expander sleeve moves from the first position to the second position.
In one aspect, a gap formed between a side of the seal member and a side of the groove which is configured to close as the expander sleeve moves from the first position to the second position. In another aspect, a second seal member disposed in a second groove formed in the inner surface of the expandable annular member, the second seal member having one or more anti-extrusion spring bands embedded within the seal member. In another aspect, the second seal member is configured to create a seal with the expander sleeve.
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.
This application claims benefit of U.S. provisional patent application Ser. No. 61/563,016 filed Nov. 22, 2011 and is a continuation-in-part of co-pending U.S. patent application Serial No. 13/029,022, filed Feb. 16, 2011. Each of the aforementioned related patent applications is herein incorporated by reference.
Number | Date | Country | |
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61563016 | Nov 2011 | US |
Number | Date | Country | |
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Parent | 13029022 | Feb 2011 | US |
Child | 13398829 | US |