Expandable packer system
The expandable casing packing element systems for cased and open-hole wellbores include an expandable casing member having a sealing device comprising a sealing element disposed between at least two retainer rings. The retainer rings have flat cross-sections and the sealing element is forced radially outward by the expansion of the expandable casing against the two retainer rings such that the sealing element protrudes outwardly beyond the retainer rings and engages the wall of a wellbore in three locations. The retainer rings can also include flares that extend outwardly from the body of the expandable casing to which they are attached. As the expandable casing is expanded, the flares are forced inward to compress the sealing element which is then extruded radially outward through a gap between the two retainer rings to engage and seal off the wellbore.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/933,183 filed Jun. 5, 2007.
BACKGROUNDThe invention is directed to expandable casing packing element systems for use in oil and gas wells and, in particular, expandable casing packing element systems having extrudable sealing elements for sealing open-hole wells.
Expandable casing having a sealing element such as a packer have been used to seal the annulus of open-hole wells. In operation, after the well is drilled into the earth formation, the expandable casing is run into the well. The expandable casing has disposed on it, or as part of the expandable casing string, a sealing device such as a packer. The packer is designed to divide the well by sealing against the well formation, thereby isolating a lower portion of the well from an upper portion of the well.
After the expandable casing is run into the desired location in the well, a cone or other device can be transported through the bore of the expandable casing. As the cone, such as a swage, travels downward, the expandable casing is expanded by the cone. The expansion of the expandable casing causes the sealing device to contact the formation and separate the open-hole well into at least two isolated regions, one above the sealing device and one below the sealing device.
The expandable casing and sealing devices disclosed herein include components that, to the inventors' knowledge, are novel and non-obvious from previous expandable casing and sealing devices.
SUMMARY OF INVENTIONBroadly, the expandable casing packing element systems disclosed herein include an expandable casing member having a sealing device comprising a sealing element disposed between at least two retainer rings. In one embodiment, both retainer rings have flat cross-sections and the sealing element is forced radially outward by the expansion of the expandable casing against the two retainer rings such that the sealing element protrudes outwardly beyond the retainer rings and engages the wall of the a wellbore in three locations. The wellbore may be an opened-hole wellbore or a cased wellbore. In another embodiment, both of the two retainer rings include flares that extend outwardly from the body of the expandable casing to which they are attached. As the expandable casing is expanded, the flares are forced inward to compress the sealing element which is then extruded radially outward through a gap between the two retainer rings to engage and seal off the wellbore.
Also disclosed is a method comprising the steps of: (a) running an expandable casing string having a packing element system attached thereto into a wellbore defined by an inner wall surface, the packing element system having a sealing element and at least two retainer rings, at one of the at least two retainer rings overlapping the sealing element; (b) applying a radial load to expand the expandable casing, causing the sealing element to be extruded outwardly by at least one of the at least two retainer rings applying an inward force to the sealing element; and (c) continuing to apply the radial load causing the sealing element to move radially outward into sealing engagement with the inner wall surface of the wellbore. In one particular embodiment, the wellbore is cased. In another specific embodiment, the wellbore is an opened-hole wellbore.
While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTIONReferring now to
As illustrated in
Sealing devices 50, 60 include annular deformable sealing elements 51 having upper ends 52 and lower ends 54, upper retainer ring 56, and lower retainer ring 58. Sealing element 51 is a deformable element formed from an deformable material so that radial outward movement of sealing element 51 away from axis 40 and into upper and lower retainer rings 56, 58 causes sealing element 51 to extrude into sealing contact with inner wall surface 22 of well 20. Suitable materials for forming sealing element 51 include, but are not limited to, elastomers, rubbers, polymers, or thermoplastics.
Additionally, sealing element 51 may have any shape desired or necessary to provide the requisite compression, deformation, or “extrusion” to form the seal with inner wall surface 22 of well 20. As shown in
Further, in the embodiment shown in
Sealing element 51 is maintained against outer wall surface 39 of expandable casing 30 using any device or method known to persons of ordinary skill in the art. For example, sealing element 51 may be chemically bonded to outer wall surface 39. Alternatively, sealing element 51 can be maintained solely by upper and lower retainer rings 56, 58.
Upper retainer rings 56 and lower retainer rings 58 are expandable members disposed around the outer diameter of sealing element 51 and, thus, can maintain or assist in maintaining sealing element 51 along outer wall surface 39. In this embodiment both upper retainer ring 56 and lower retainer ring 58 have a relatively flat vertical cross-section parallel or substantially parallel to the axial length of the expandable casing 30. As additionally shown in
Although the shape of upper and lower retainer rings 56, 58 are discussed with reference to
Further, upper and lower retainer rings 56, 58 may be formed from any material known to persons of ordinary skill in the art. For example, one or both of upper and lower retainer rings 56, 58 may be formed from stiffer elastomers, polymers, or metals such as steel.
After expandable casing 30 is properly located within well 20, a cone (not shown) or other expanding device is run through bore 36 of expandable casing 30. As the cone travels downward, i.e., downhole, expandable casing 30 is forced radially outward from axis 40. In so doing, run-in diameter 42 is radially expanded to transition diameter 46 and ultimately to set diameter 44. As a result of the radial expansion of expandable casing 30, sealing element 51 is forced into upper and lower retainer rings 56, 58. Although upper and lower retainer rings 56, 58 are radially expandable, they are formed from a material that is stronger, i.e., more resistance to expansion, compared to the material used to form sealing element 51. As a result, as expandable casing 30 is expanded, sealing material 51 is compressed, deformed, or extruded in between outer wall surface 39 of expandable casing and the inner wall surfaces of upper and lower retainer rings 56, 58 defined by the inner diameters of upper and lower retainer rings 56, 58. Due to the compression of sealing element 51 between outer wall surface 39 of expandable casing 30 and the inner wall surfaces of upper and lower retainer rings 56, 58, the center portion of sealing element 51 is extruded outwardly in between upper and lower retainer rings 56, 58; upper end 52 of sealing element 51 is extruded outwardly above upper retainer ring 56; and lower end 54 of sealing element 51 is extruded outwardly below lower retainer ring 58 until all three portions of sealing element 51 form a seal against inner wall surface 22 of well 20. The distance between the outer diameter of upper and lower retainer rings 56, 58 and inner wall surface 22 of well 20 is referred to as the extrusion gap.
Referring now to
As illustrated in
Sealing device 150 includes annular sealing element 151, upper retainer ring 156 and lower retainer ring 158. Annular sealing element 151 is a deformable element formed from a deformable material such as those discussed above with respect to sealing element 51. In this embodiment, sealing element 151 has a trapezoid section such that the inner surface of sealing element 151 has a longer axial length along outer wall surface 139 than the axial length of the outer surface defined by the outer diameter of sealing element 151.
Upper retainer ring 156 has upper flare portion 157 and lower retainer ring 158 has lower flare portion 159 thereby forming a cavity between upper retainer ring 156 and lower retainer ring 158 with a gap between the lowermost end of upper retainer ring 156 and the uppermost end of lower retainer ring 158. Sealing element 151 is disposed within the cavity. In one specific embodiment, sealing element 151 is maintained along outer wall surface 139 through any device or method known to persons of ordinary skill in the art, such as through chemical bonding or by upper and lower retainer rings 156, 158.
As with the embodiment shown in
Upper flare portion 157 and lower flare portion 159 may have any shape or angle relative to the remaining vertical portions of upper and lower flare portions. For example, upper and lower flare portions 157, 159 may be at an angle in a range greater than 0 degrees and less than 90 degrees relative to the vertical portions of upper and lower flare portions 157, 159. Additionally, the angle at which upper flare portion 157 intersects the remaining portion of upper retainer ring may be different from the angle at which lower flare portion 159 intersects the remaining portion of lower retainer ring 158. In one specific embodiment, both of these angles are within the range from 30 degrees to 60 degrees so that sufficient inward force can be applied to sealing element 151 during expansion of expandable casing 130 to extrude sealing element 151 through the gap between the lowermost and uppermost ends of upper retainer ring 156 and lower retainer ring 158, respectively. In the embodiment shown in
Upper and lower retainer rings 156, 158 can be secured to outer wall surface 139 through any device or method known to persons of ordinary skill in the art. For example, upper and lower retainer rings 156, 158 may be welded or epoxied to outer wall surface 139. Alternatively, upper and lower retainer rings 156, 158 may be secured or formed integral with an expandable mandrel (not shown) that is then secured such as through threads to an expandable casing string.
As shown in
After expandable casing 130 is properly located within well (not shown), a cone (not shown) or other expanding device is run through bore 136 of expandable casing 130. As the cone travels downward, i.e., downhole, expandable casing 130 is forced radially outward from axis 140. In so doing, the run-in diameter illustrated by run-in radius 142 is radially expanded to a transition diameter (not shown) and ultimately to set diameter illustrated by set radius 144 (
Due to the compression of sealing element 151 between outer wall surface 139 of expandable casing 130 and the upper and lower flare portions 157, 159, sealing element 151 is extruded outwardly from the cavity through the gap located between the lowermost end of upper retainer ring 156 and the upper most end of lower retainer ring 158 until sealing element 151 forms a seal against the inner wall surface of the well. This distance between the outermost diameters of upper and lower retainer rings 156, 158 and the inner wall surface of the well is referred to as the extrusion gap.
It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. For example, the sealing devices may be disposed on an expandable mandrel that is placed within an expandable casing string. Additionally, the expandable casing may have one or more sealing devices 50 or 60 together with one or more sealing devices 150. Moreover, a spacer may be disposed in between outer wall surface 39 of expandable casing 30 and the inner diameter of sealing element 151 to assist in extrusion of sealing element 151 during expansion of expandable casing 130. Further, the inner diameter of upper retainer ring 56 is not required to be equal to the inner diameter of lower retainer ring 58. Likewise, the shape of upper flare portion 157 is not required to be the same shape as lower flare portion 159. Additionally, the expandable casing 30, 130 may be disposed in a cased wellbore as opposed to an open-hole wellbore. Thus, the term “wellbore” as used herein includes a cased wellbore as well as an opened-hole wellbore. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
Claims
1-20. (canceled)
21. A sealing device for a radially expandable casing, the sealing device comprising:
- a first retainer ring comprising a first end portion and a second end;
- a second retainer ring;
- a gap disposed between the first retainer ring and the second retainer ring; and
- an extrudable sealing element disposed between the first retainer ring and the second retainer ring and in fluid communication with the gap, the extrudable sealing element being extrudable through the gap when the expandable casing is radially expanded from a first position to a second position, wherein during expansion of the expandable casing toward the second position, the second end portion of the first retainer ring is moved with respect to an outer wall surface of the expandable casing toward an axis of the expandable casing.
22. The sealing device of claim 21, wherein the second retainer ring comprising a second retainer ring first end portion and a second retainer ring second end portion, and
- wherein during expansion of the expandable casing toward the second position, the second retainer ring second end portion of the second retainer ring is moved with respect to an outer wall surface of the expandable casing toward the axis of the expandable casing.
23. A sealing device for a radially expandable casing, the sealing device comprising:
- a first retainer ring comprising a first end portion disposed substantially parallel to an axis of the expandable casing and a second end portion disposed at a first initial angle relative to the first end portion, the first initial angle being less than 90 degrees and more than 0 degrees;
- a second retainer ring;
- a gap disposed between the first retainer ring and the second retainer ring; and
- an extrudable sealing element disposed between the first retainer ring and the second retainer ring and in fluid communication with the gap, the extrudable sealing element being extrudable through the gap when the expandable casing is radially expanded from a first position to a second position, wherein during expansion of the expandable casing toward the second position, the first initial angle is reduced.
24. The sealing device of claim 23, wherein the second retainer ring comprises a second retainer ring first end portion disposed substantially parallel to the axis of the expandable casing and a second retainer ring second end portion disposed at a second initial angle relative to the second retainer ring first end portion, the second initial angle being less than 90 degrees and more than 0 degrees;
- wherein during expansion of the expandable casing toward the second position, the second initial angle is reduced.
25. A sealing device for a radially expandable casing, the sealing device comprising:
- a first retainer ring;
- a second retainer ring;
- a gap disposed between the first retainer ring and the second retainer ring; and
- an extrudable sealing element disposed between the first retainer ring and the second retainer ring and in fluid communication with the gap, the extrudable sealing element being extrudable through the gap when the expandable casing is radially expanded from a run-in casing radius to a set casing radius, the set casing radius being greater than the run-in casing radius and the difference between the set casing radius and the run-in casing radius defining a casing radius differential, wherein during expansion of the expandable casing, a portion of the first retainer ring is radially expanded outward from a first run-in ring radius, as measured from an axis of the expandable casing to the portion of the first retainer ring, to a first set ring radius, as measured from the axis of the expandable casing to the portion of the first retainer ring, the first set ring radius being greater than the first run-in ring radius, and the difference between the first set ring radius and the first run-in ring radius defining a first ring radius differential, and wherein the casing radius differential is greater than the first ring radius differential.
26. The sealing device of claim 25, wherein during expansion of the expandable casing,
- a portion of the second retainer ring is radially expanded outward from a second run-in ring radius, as measured from the axis of the expandable casing to the portion of the second retainer ring, to a second set ring radius, as measured from the axis of the expandable casing to the portion of the second retainer ring, the second set ring radius being greater than the second run-in ring radius, and the difference between the second set ring radius and the second run-in ring radius defining a second ring radius differential, and
- wherein the casing radius differential is greater than the second ring radius differential.
Type: Application
Filed: Oct 19, 2010
Publication Date: Feb 17, 2011
Inventors: Keven O'Connor (Houston, TX), Mark K. Adam (Houston, TX), Jeffrey C. Williams (Cypress, TX)
Application Number: 12/925,319
International Classification: E21B 33/12 (20060101);