Centralizer with integral stop collar

Abstract

A centralizer is disclosed. The centralizer includes a bow spring body having a plurality of bows. The centralizer also includes a first collar assembly located at a first end of the bow spring body. The centralizer further includes a second collar assembly located at a second end of the bow spring body. Each collar assembly includes a grip ring that is configured to move from a retracted position to an engaged position, wherein the bow spring body, the first and the second collar assembly may move axially relative to the grip ring when in the engaged position.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 777,049, filed on Mar 25, 2025, which is incorporated by reference.BACKGROUND

[0002] Within the area of subterranean well construction, centralizers are used to keep the tubular casing centered in the wellbore to facilitate placement of the casing in the bore and to prevent cementing the pipe against a side of the borehole. Centralizers isolate the outer surface of the wellbore pipe from the inner surface of the wellbore. Additionally, in long horizontal sections of wellbore, centralizers provide support for the tubular casing section, preventing the wellbore pipe from laying on the lower inner surface of the horizontal wellbore. In some instances, a stop collar may be connected to the centralizer to hold the centralizer on the tubular. Therefore, there is a need for a centralizer with an integral stop collar.SUMMARY

[0003] A centralizer is disclosed. The centralizer includes a bow spring body having a plurality of bows. The centralizer also includes a first collar assembly located at a first end of the bow spring body. The centralizer further includes a second collar assembly located at a second end of the bow spring body. Each collar assembly includes a grip ring that is configured to move from a retracted position to an engaged position, wherein the bow spring body, the first and the second collar assembly may move axially relative to the grip ring when in the engaged position.

[0004] A method of using a centralizer is disclosed. The method includes placing the centralizer on the casing. The centralizer includes a grip ring. The method also includes releasing the grip ring to allow the grip ring to contact the casing. The method further includes energizing the grip ring by moving the centralizer in an axial direction relative to the grip ring. Additionally, the method includes allowing the centralizer to rotate and move axially relative to the grip ring and the casing.

[0005] A centralizer for use with a casing in a wellbore is disclosed. The centralizer includes a bow spring body having a plurality of bows. The centralizer further includes a first collar assembly located at a first end of the bow spring body. The centralizer also includes a second collar assembly located at a second end of the bow spring body. Each collar assembly includes a grip ring configured to move from a retracted position to an engaged position and a radial gap between an inner surface of the collar assembly and an outer surface of the casing, wherein the radial gap allows upset ends of the bows to transfer a side load to the grip ring while preventing the bows from contacting the casing when the bows are compressed by a wellbore restriction. The bow spring body, the first collar assembly, and the second collar assembly are configured to move axially relative to the grip ring when the grip ring is in the engaged positionBRIEF DESCRIPTION OF THEDRAWINGS

[0006] The present disclosure may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention. In the drawings:

[0007] FIG. 1 illustrates a side view of a centralizer, according to an embodiment.

[0008] FIG. 2 illustrates an end view of the centralizer, according to an embodiment.

[0009] FIG. 3A illustrates a cross-sectional view of a centralizer in a first (e.g. pre-installed) position, according to an embodiment.

[0010] FIG. 3B illustrates a cross-sectional view of the centralizer in a second position with grip rings deployed, according to an embodiment.

[0011] FIG. 3C illustrates a cross-sectional side view of the centralizer in a third (e.g., engaged) position with grip rings engaged, according to an embodiment.

[0012] FIG. 3D is a sectional view of the centralizer in a fourth position with bows compressed, according to an embodiment.

[0013] FIG. 3E is a sectional view of the centralizer in a fifth position, according to an embodiment.

[0014] FIG. 3F is a sectional view of the centralizer in a sixth position, according to an embodiment.

[0015] FIG. 3G is a sectional view of the centralizer in a seventh position, according to an embodiment.

[0016] FIG. 3H is a sectional view of the centralizer in an eighth (e.g., disengaged) position, according to an embodiment.

[0017] FIG. 4A illustrates a cross-sectional view of a centralizer in a first (e.g. pre-installed) position, according to an embodiment.

[0018] FIG. 4B illustrates a cross-sectional view of the centralizer in a second position with grip rings deployed, according to an embodiment.

[0019] FIG. 4C is a sectional view of the centralizer in a third position, according to an embodiment.

[0020] FIG. 4D is a sectional view of the centralizer in a fourth position, according to an embodiment.

[0021] FIG. 5A illustrates a cross-sectional view of a centralizer in a first (e.g. pre-installed) position, according to an embodiment.

[0022] FIG. 5B illustrates a cross-sectional view of the centralizer in a second position with grip rings deployed, according to an embodiment.

[0023] FIG. 5C illustrates a cross-sectional side view of the centralizer in a third (e.g., engaged) position with grip rings engaged, according to an embodiment.

[0024] FIG. 5D is a sectional view of the centralizer in a fourth position with bows compressed, according to an embodiment.

[0025] FIG. 5E is a sectional view of the centralizer in a fifth position, according to an embodiment.

[0026] FIG. 5F is a sectional view of the centralizer in a sixth position, according to an embodiment.

[0027] FIG. 5G is a sectional view of the centralizer in a seventh (e.g., disengaged) position, according to an embodiment.

[0028] FIG. 6 is an enlarged sectional view of the centralizer, according to an embodiment.

[0029] FIG. 7 illustrates a flowchart of a method for operating a centralizer on a casing, according to an embodiment.

[0030] FIG. 8A illustrates a cross-sectional view of a centralizer in a pre-engaged position, according to an embodiment.

[0031] FIG. 8B illustrates a cross-sectional side view of the centralizer in an engaged position with grip rings engaged, according to an embodiment.DETAILED DESCRIPTION

[0032] The following disclosure describes several embodiments for implementing different features, structures, or functions of the invention. Embodiments of components, arrangements, and configurations are described below to simplify the present disclosure. However, these embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference characters (e.g., numerals) and / or letters in the various embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed in the Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact. It may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the embodiments presented below may be combined in any combination of ways. For example, any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.

[0033] Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names. As such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Additionally, in the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion. Thus, they should be interpreted to mean “including, but not limited to.” All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. In addition, unless otherwise provided herein, “or” statements are intended to be non-exclusive. For example, the statement “A or B” should be considered to mean “A, B, or both A and B.”

[0034] FIG. 1 illustrates a side view of a centralizer 100, according to an embodiment. As described herein, the centralizer 100 includes a first collar assembly 125 with a self-locking mechanism and a second collar assembly 175 with a self-locking mechanism. The centralizer 100 further includes a bow body 150 that includes a plurality of bow springs. The first collar assembly 125 may be connected to one end of the body 150 by welding. The second collar assembly 175 may be connected to another end of the bow body 150 by welding (FIGS. 3A and 3B). Alternatively, the first collar assembly 125, the bow body 150, and the second collar assembly 175 may be made from a single piece (FIG. 5A). Each collar assembly 125, 175 includes a grip ring (not shown) that is held in place by a connection member 75. FIG. 2 illustrates an end view of the centralizer 100, according to an embodiment. As shown, the second collar assembly 175 is connected to the bow body 150.

[0035] FIG. 3A illustrates a cross-sectional view of a centralizer 300 in a first (e.g. pre-installed) position, according to an embodiment. The centralizer 300 is placed on a casing 50. The centralizer 300 includes a first collar assembly 325, a bow spring body 350, and a second collar assembly 375. The first collar assembly 325 and the second collar assembly 375 are welded to the bow spring body 350 at weld 25.

[0036] The first collar assembly 325 will be described herein. The second collar assembly 375 has similar components and functions in a similar manner to the first collar assembly 325. The first collar assembly 325 includes a self-locking mechanism, which comprises a collar body 330 and a grip ring 345 that engages the casing through a wedging action. In the pre-installed position, the grip ring 345 is held in a retracted position within the collar body 330 by a connection member 75, such as a screw. The collar body 330 includes a first shoulder 335 and a second shoulder 340.

[0037] FIG. 3B illustrates a cross-sectional view of the centralizer 300 in a second position with grip rings 345 deployed, according to an embodiment. As shown, the connection members 75 have been removed, which allows the grip ring 345 to move into contact with an outer surface of the casing 50. In other words, the grip ring 345 has moved from a retracted position (FIG. 3A) to an engaged position (FIG. 3B). The grip ring 345 may include a grip profile on an outer surface. The grip profile may comprise wickers, teeth, or serrations that are configured to grip into the outer surface of the casing 50.

[0038] FIG. 3C illustrates a cross-sectional side view of the centralizer 300 in a third position in which the grip ring 345 is engaged, according to an embodiment. External axial applied forces have moved the centralizer 300 in a first axial direction 305. This causes the body 330 to come into contact with the grip ring 345. As shown, the grip ring 345 has engaged with a taper on the inner surface of the body 330. As also shown, the grip ring 345 is fully engaged with the outer surface of casing 50. In other words, the grip profile of the grip ring 345 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 300 are run into a wellbore. Further, the centralizer 300 may move axially relative to the grip ring 345 and the casing 50. The centralizer 300 may also rotate relative to the grip ring 345 and the casing 50.

[0039] FIG. 3D is a sectional view of the centralizer 300 in a fourth position with the bows in the bow spring body 350 compressed, according to an embodiment. As the casing 50 and the centralizer 300 are run into the wellbore in the first axial direction 305, the centralizer 300 may encounter a restriction 10 in the wellbore. This restriction causes the bows in the bow spring body 350 to compress toward the casing 50. As shown, the bows of the bow spring body 350 are closer to the outer surface of the casing 50 in FIG. 3D as comparison to the bows in the body 350 shown in FIG. 3C. As also shown, the grip ring 345 in the second collar assembly 375 has engaged the shoulder 340 in the collar body 330. However, the grip ring 345 in the second collar assembly 375 is free to move in the axial direction 305 due to the grip profile (wicker) orientation.

[0040] FIG. 3E is a sectional view of the centralizer 300 in a fifth position, according to an embodiment. After the centralizer 300 moves through the restriction 10 (FIG. 3D) and into an open area (e.g., open hole), the bows of the bow spring body 350 expand radially outward.

[0041] FIG. 3F is a sectional view of the centralizer 300 in a sixth position, according to an embodiment. The centralizer 300 is under a high axial load as the centralizer 300 moves relative to the casing 50 in the first axial direction 305. As shown, the grip ring 345 has engaged the first shoulder 335. This engagement causes a high axial load on the centralizer 300 as the centralizer moves in the axial direction 305.

[0042] FIG. 3G is a sectional view of the centralizer in a seventh position, according to an embodiment. The grip ring 345 in the first collar assembly 325 has been moved from the engaged position (FIG. 3F) to the retracted position (FIG. 3G). The retraction of the grip ring 345 can be done by placing the connection member 75 in a hole or a slot in the collar body 330. The connection member 75 is inserted until it engages with a hole in the grip ring 345. The connection member 75 is then used to move the grip ring 345 from the engaged position to the retracted position. A similar procedure can be used to move the grip ring 345 in the second collar assembly 375 from the engaged position to the retracted position.

[0043] FIG. 3H is a sectional view of the centralizer 300 in an eighth (e.g., disengaged) position, according to an embodiment. As shown, the grip ring 345 in both the first and second collar assembly 325, 375 are in the retracted position. At this time, the centralizer 300 is disengaged from the casing 50 and may be removed.

[0044] FIG. 4A illustrates a cross-sectional view of a centralizer 400 in a first (e.g. pre-installed) position, according to an embodiment. The centralizer 400 is placed on a casing 50. The centralizer 400 includes a first collar assembly 425, a bow spring body 450, and a second collar assembly 475. The first collar assembly 425 and the second collar assembly 475 are welded to the bow spring body 450 at weld 25.

[0045] The first collar assembly 425 will be described herein. The second collar assembly 475 has similar components and functions in a similar manner to the first collar assembly 425. The first collar assembly 425 includes a self-locking mechanism, which comprises a collar body 430 and a grip ring 445 that engages the casing. In the pre-installed position, the grip ring 445 is held in a retracted position within the collar body 430 by a connection member 75, such as a screw. The collar body 430 includes an inner surface 435 and a shoulder 440. As shown, the shoulder 440 is a portion of the bow spring body 450.

[0046] FIG. 4B illustrates a cross-sectional view of the centralizer in a second position with grip rings deployed, according to an embodiment. As shown, the connection members 75 have been removed. This allows the grip ring 445 to move into contact with an outer surface of the casing 50. In other words, the grip ring 445 has moved from a retracted position (FIG. 4A) to an engaged position (FIG. 4B). The grip ring 445 may include a grip profile, such as wickers, teeth or serrations, on a surface. The grip profile is configured to grip (or bite or penetrate) into the outer surface of the casing 50.

[0047] FIG. 4C is a sectional view of the centralizer 400 in a third position, according to an embodiment. External axial applied forces have moved the centralizer 400 in a first axial direction 405. This causes the inner surface 435 of the body 430 to come into contact with the grip ring 445. As shown, the grip ring 445 has engaged with a taper on the inner surface 435 of the body 430. As also shown, the grip ring 445 is fully engaged with the outer surface of casing 50. This can be accomplished using low to moderate axial load. In other words, the grip profile of the grip ring 445 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 400 are run into a wellbore. Further, the centralizer 400 may move axially relative to the grip ring 445 and the casing 50. The centralizer 400 may also rotate relative to the grip ring 445 and the casing 50.

[0048] FIG. 4D is a sectional view of the centralizer 400 in a fourth position, according to an embodiment. The centralizer 400 is under a high axial load as the centralizer 400 moves relative to the casing 50 in the first axial direction 405. As shown, the grip ring 445 in the first collar assembly 425 has engaged the inner surface 435. The grip ring 445 in the second collar assembly 475 has engaged the shoulder 440. This causes a high axial load on the centralizer 400 as the centralizer moves in the axial direction 405. Further, as shown, a back hook 455 in the first collar assembly 425 has engaged the inner surface 435 of the collar body 430. The back hook 455 is a rearward-facing protrusion on the grip ring 445 that provides additional load resistance under high axial loads.

[0049] The grip ring 445 in the first collar assembly 425 of the centralizer 400 may be moved from the engaged position (FIG. 4D) to the retracted position (FIG. 4A). The retraction of the grip ring 445 can be done by placing the connection member 75 in a hole or a slot in the collar body 430. The connection member 75 is inserted until it engages with a hole in the grip ring 445. The connection member 75 is then used to move the grip ring 445 from the engaged position to the retracted position. A similar procedure can be used to move the grip ring 445 in the second collar assembly 475 from the engaged position to the retracted position.

[0050] FIG. 5A illustrates a cross-sectional view of a centralizer 500 in a first (e.g. pre-installed) position, according to an embodiment. The centralizer 500 is placed on a casing 50. The centralizer 500 includes a first collar assembly 525, a bow spring body 550, and a second collar assembly 575. The first collar assembly 525, the second collar assembly 575 and the bow spring body 550 are a single body. In other words, the first and second collar assemblies 525, 575 are not welded to the bow spring body 550 as shown in centralizers 300, 400. The centralizer 500 may be used in a wellbore that requires a high tolerance centralizer.

[0051] The first collar assembly 525 will be described herein. The second collar assembly 575 has similar components and functions in a similar manner to the first collar assembly 525. The first collar assembly 525 includes a self-locking mechanism, which comprises a collar body 530 and a grip ring 545 that engages the casing through a wedging action. In the pre-installed position, the grip ring 545 is held in a retracted position within the collar body 530 by a connection member 75, such as a screw. The collar body 530 includes a taper 535.

[0052] FIG. 5B illustrates a cross-sectional view of the centralizer 500 in a second position with grip rings 545 deployed, according to an embodiment. As shown, the connection members 75 have been removed, which allows the grip ring 545 to move into contact with an outer surface of the casing 50. In other words, the grip ring 545 has moved from a retracted position (FIG. 5A) to an engaged position (FIG. 5B). The grip ring 545 may include a grip profile, such as wickers, teeth or serrations, on a surface. The grip profile is configured to grip (or bite or penetrate) into the outer surface of the casing 50.

[0053] FIG. 5C illustrates a cross-sectional side view of the centralizer 500 in a third position in which the grip ring 545 is engaged, according to an embodiment. External axial forces have moved the centralizer 500 in a first axial direction 505. This causes the body 530 to come into contact with the grip ring 545. As shown, the grip ring 545 has engaged with the taper 535 on the inner surface of the body 530. As also shown, the grip ring 545 is fully engaged with the outer surface of casing 50 in the engaged position. In other words, the grip profile of the grip ring 545 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 500 are run into a wellbore. Further, the centralizer 500 may move axially relative to the grip ring 545 and the casing 50. The centralizer 500 may also rotate relative to the grip ring 545 and the casing 50.

[0054] FIG. 5D is a sectional view of the centralizer 500 in a fourth position, according to an embodiment. External axial applied forces have moved the centralizer 500 in a second axial direction 510. This causes the body 530 to come into contact with the grip ring 545 in the second collar assembly 575. As shown, the grip ring 545 has engaged with the taper 535 on the inner surface of the body 530. As also shown, the grip ring 545 is fully engaged with the outer surface of casing 50. In other words, the grip profile of the grip ring 545 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 500 are pulled out of the wellbore.

[0055] FIG. 5E is a sectional view of the centralizer 500 in a fifth position with the bows in the bow spring body 550 compressed, according to an embodiment. As the casing 50 and the centralizer 500 are run into the wellbore in the first axial direction 505, the centralizer 500 may encounter a restriction 10. This restriction causes the bows in the bow spring body 550 to compress toward the casing 50. As shown, the bows of the bow spring body 550 are closer to the outer surface of the casing 50 in FIG. 5E as compared to the bows in the body 550 shown in FIG. 5C. As also shown, the grip ring 545 in the second collar assembly 575 has engaged the taper 535 in the collar body 530.

[0056] FIG. 5F is a sectional view of the centralizer 500 in a sixth position, according to an embodiment. The centralizer 500 is under high axial load as the centralizer 500 moves relative to the casing 50 in the first axial direction 505. As shown, the grip ring 545 has engaged the taper 535, thereby inducing high axial stress on the centralizer 500 during axial movement in direction 505. As also shown, a back hook 555 in the first collar assembly 525 has engaged the taper 535 in the collar body 530 under the high axial load. The back hook 555 is a rearward-facing protrusion on the grip ring 545 configured to provide bidirectional load resistance. Under the high axial load, the collar body 530 undergoes plastic deformation. This deformation continues until the back hook 555 achieves full engagement with the collar body 530. Once fully engaged, the back hook 555 creates a load-bearing interface with the collar body 530. This interface prevents relative displacement between the grip ring 545 and the collar body 530 under operational loading.

[0057] FIG. 5G is a sectional view of the centralizer 500 in a seventh (e.g., disengaged) position, according to an embodiment. As shown, the grip ring 545 in both the first and second collar assembly 525, 575 are in the retracted position. At this time, the centralizer 500 is disengaged from the casing 50 and may be removed. The grip ring 545 in the first collar assembly 525 has been moved from the engaged position (FIG. 5F) to the retracted position (FIG. 5G). The retraction of the grip ring 545 can be done by placing the connection member 75 in a hole or a slot in the collar body 530. The connection member 75 is inserted until it engages with a hole in the grip ring 545. The connection member 75 is then used to move the grip ring 545 from the engaged position to the retracted position. A similar procedure can be used to move the grip ring 545 in the second collar assembly 575 from the engaged position to the retracted position.

[0058] FIG. 6 is an enlarged sectional view of the centralizer 500, according to an embodiment. As shown, the bows of the bow body 550 are substantially flat and may contact an outer surface 570 of the casing 50 as the centralizer 500 goes through the restriction 10. During this compression, the bow structure undergoes elastic deflection and potentially plastic deflection as it experiences compressive loading from the wellbore restriction. A side load 560 is generated during compression. The side load 560 represents a radial force vector normal to the longitudinal axis of the centralizer 500. This side load 560 is transferred through the upset ends of the bows into the grip rings 545. From the grip rings 545, the load is transferred to the outer surface of the casing 50. This creates a load path that redirects the reaction forces through the end connections. The radial gap 565 provides a relief area for the loaded bow of the bow body 550. This gap functions as a clearance zone that permits controlled radial deflection of the bow structure. The radial gap 565 maintains contact between the bow upset ends and the grip ring assembly while allowing deflection. Without the radial gap 565 and the transfer of the side load 560, the loaded bow would be overstressed beyond its elastic limit. This overstress would cause the bow to take a permanent set, which is plastic deformation. The plastic deformation would reduce the restoring force of the bow by compromising its elastic recovery characteristics. This would reduce the radial centralization force that maintains standoff distance between the casing outer diameter and the wellbore inner diameter. The radial gap 565 decouples the bow deflection from direct compressive loading against the casing surface. This decoupling allows the upset ends to function as pivot points. These pivot points redistribute bending moments and shear forces away from the mid-span section of the bow. By redistributing these forces, the radial gap 565 preserves the structural integrity and elastic properties of the spring element. This preservation allows the bow to maintain its function throughout multiple compression cycles during wellbore navigation.

[0059] FIG. 7 illustrates a flowchart 700 of a method for operating the centralizer 300, 400, 500 on a casing 50, according to an embodiment. An illustrative order of the method 700 is provided below, however, one or more steps of the method 700 may be performed in a different order, simultaneously, repeated, or omitted. Further, the method 700 could apply to any embodiment described herein. Additionally, the method will be described in relation to the centralizer 300, but it can be applied to centralizers 400, 500, and 800.

[0060] The method 700 may include placing the centralizer on the casing, as at 705. The centralizer 300 shown in FIG. 3A is in the pre-installed position on the casing 50.

[0061] The method 700 may include releasing the grip rings in the centralizer to allow the grip rings to contact the casing, as at 710. The grip rings 345 of the centralizer 300 are released as shown in FIG. 3B.

[0062] The method 700 may include moving the centralizer in an axial direction relative to grip rings to energize the grip rings on the casing, as at 715. The centralizer 300 is moved in an axial direction 305 in FIG. 3C to energize the grip ring 345.

[0063] The method 700 may include allowing the centralizer to rotate and move axially relative to the grip rings, as at 720. The centralizer 300 is able to rotate and move axially to the grip ring 345 as shown in FIG. 3E.

[0064] The method 700 may include de-activating the grip ring to allow the centralizer to be removed from the casing, as at 725. The grip ring 345 of centralizer 300 is de-activated in FIG. 3H and the centralizer 300 is able to be removed from the casing 50.

[0065] FIG. 8A illustrates a cross-sectional view of a centralizer 800 in a pre-engaged position, according to an embodiment. The centralizer 800 is placed on a casing 50. The centralizer 800 includes a first collar assembly 825, a bow spring body 850, and a second collar assembly 875. The first collar assembly 825, the second collar assembly 875 and the bow spring body 850 are a single body. In other words, the first and second collar assemblies 825, 875 are not welded to the bow spring body 850 as shown in centralizers 300, 400. The centralizer 800 may be used in a wellbore that requires a high tolerance centralizer.

[0066] The first collar assembly 825 will be described herein. The second collar assembly 875 has similar components and functions in a similar manner to the first collar assembly 825. The first collar assembly 825 includes a self-locking mechanism, which comprises a collar body 830 and a grip ring 845 that engages the casing 50 through a wedging action. In the pre-installed position, the grip ring 845 is held in a retracted position within the collar body 830 by a connection member 75, such as a screw.

[0067] The collar body 830 includes a ramp 840 and a shoulder 835. The ramp 840 may have an angle of between 5 degrees and 25 degrees relative to a longitudinal axis of the collar body 830. In some embodiments, the ramp angle is between 10 degrees and 20 degrees. The ramp 840 may have an axial length of between 0.25 inches and 2.0 inches. In some embodiments, the axial length is between 0.5 inches and 1.5 inches. The shoulder 835 may extend radially inward from the inner surface of the collar body 830. The radial extension distance may be between 0.05 inches and 0.5 inches. In some embodiments, the radial extension is between 0.1 inches and 0.3 inches. The shoulder 835 may be formed on the collar body 830 by using a roller. In this method, the roller applies radial force to the inner surface of the collar body 830 while the collar body 830 is rotated. This plastically deforms the material to create the shoulder 835 in a controlled manner. Alternatively, the shoulder 835 may be formed on the collar body 830 by using a swage. In this method, a mandrel or die is forced through or into the collar body 830. This radially displaces the material and forms the shoulder 835 through cold working of the metal.

[0068] FIG. 8B illustrates a cross-sectional view of the centralizer 800 in a second position with grip rings 845 deployed, according to an embodiment. As shown, the connection members 75 have been removed, which allows the grip ring 845 to move into contact with an outer surface of the casing 50. In other words, the grip ring 845 has moved from a retracted position (FIG. 8A) to an engaged position (FIG. 8B). The grip ring 845 may include a grip profile, such as wickers, teeth or serrations, on a surface. The grip profile is configured to grip (or bite or penetrate) into the outer surface of the casing 50.

[0069] External axial forces have moved the centralizer 800 in a first axial direction 805. This causes the body 830 to come into contact with the grip ring 845. As shown, the grip ring 845 has moved along the ramp 840. A nose 885 on the grip ring 845 is engaged with the shoulder 835 on the inner surface of the body 830. The nose 885 may extend radially outward from an outer surface of the grip ring 845 by a distance of between 0.05 inches and 0.5 inches. In some embodiments, this distance is between 0.1 inches and 0.3 inches. The nose 885 may have an axial length of between 0.1 inches and 1.0 inches. In some embodiments, the axial length is between 0.2 inches and 0.6 inches. When engaged, the nose 885 may contact the shoulder 835 over an engagement depth of between 0.05 inches and 0.4 inches. In some embodiments, the engagement depth is between 0.08 inches and 0.25 inches. This engagement provides a mechanical lock that resists axial movement. As also shown, the grip ring 845 is fully engaged with the outer surface of casing 50 in the engaged position. In other words, the grip profile of the grip ring 845 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 800 are run into a wellbore. Further, the centralizer 800 may move axially relative to the grip ring 845 and the casing 50. The centralizer 800 may also rotate relative to the grip ring 845 and the casing 50.

[0070] Similar to other embodiments described herein (i.e., FIG. 5D) external axial applied forces may move the centralizer 800 in a second axial direction, which causes the body 830 to come into contact with the grip ring 845 in the second collar assembly 875. The nose 885 on the grip ring 845 has engaged with the shoulder 835 on the inner surface of the body 830. The grip ring 845 is fully engaged with the outer surface of casing 50. In other words, the grip profile of the grip ring 845 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 800 are pulled out of the wellbore.

[0071] As the casing 50 and the centralizer 800 are run into the wellbore in the first axial direction 805, the centralizer 800 may encounter a restriction, which causes the bows in the bow spring body 850 to compress toward the casing 50. The bows of the bow spring body 850 may be closer to the outer surface of the casing 50.

[0072] The centralizer 800 is under a high axial load as the centralizer 800 moves relative to the casing 50 in the first axial direction 805. The grip ring 845 has moved along the ramp 840. The nose 885 on the grip ring 845 has engaged the shoulder 835. This causes a high axial load on the centralizer 800 as the centralizer moves in the axial direction 805. As also shown, a back hook 855 (a rearward-facing protrusion on the grip ring 845) in the first collar assembly 825 is engaged with the ramp 840 in the collar body 830 under the high axial load. The nose on the grip ring 845 is also engaged with the shoulder 835 in the collar body 830. The collar body 830 plastically deforms until the back hook 855 is engaged with the collar body 830.

[0073] The grip ring 845 in both the first and second collar assembly 825, 875 may be moved to the retracted position. At this time, the centralizer 800 is disengaged from the casing 50 and may be removed. The grip ring 845 in the first collar assembly 825 has been moved from the engaged position to the retracted position (similar to FIG. 8A). The retraction of the grip ring 845 can be done by placing the connection member 75 in a hole or a slot in the collar body 830. The connection member 75 is inserted until it engages with a hole in the grip ring 845. The connection member 75 is then used to move the grip ring 845 from the engaged position to the retracted position. A similar procedure can be used to move the grip ring 845 in the second collar assembly 875 from the engaged position to the retracted position.

[0074] As used herein, the terms “inner” and “outer”; “up” and “down”; “upper” and “lower”; “upward” and “downward”; “above” and “below”; “inward” and “outward”; “uphole” and “downhole”; and other like terms as used herein refer to relative positions to one another and are not intended to denote a particular direction or spatial orientation. The terms “couple,”“coupled,”“connect,”“connection,”“connected,”“in connection with,” and “connecting” refer to “in direct connection with” or “in connection with via one or more intermediate elements or members.”

[0075] The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Examples

Embodiment Construction

[0032]The following disclosure describes several embodiments for implementing different features, structures, or functions of the invention. Embodiments of components, arrangements, and configurations are described below to simplify the present disclosure. However, these embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference characters (e.g., numerals) and / or letters in the various embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed in the Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact. It may also include embodiments in which additional features may be form...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 777,049, filed on Mar 25, 2025, which is incorporated by reference.BACKGROUND

[0002] Within the area of subterranean well construction, centralizers are used to keep the tubular casing centered in the wellbore to facilitate placement of the casing in the bore and to prevent cementing the pipe against a side of the borehole. Centralizers isolate the outer surface of the wellbore pipe from the inner surface of the wellbore. Additionally, in long horizontal sections of wellbore, centralizers provide support for the tubular casing section, preventing the wellbore pipe from laying on the lower inner surface of the horizontal wellbore. In some instances, a stop collar may be connected to the centralizer to hold the centralizer on the tubular. Therefore, there is a need for a centralizer with an integral stop collar.SUMMARY

[0003] A centralizer is disclosed. The centralizer includes a bow spring body having a plurality of bows. The centralizer also includes a first collar assembly located at a first end of the bow spring body. The centralizer further includes a second collar assembly located at a second end of the bow spring body. Each collar assembly includes a grip ring that is configured to move from a retracted position to an engaged position, wherein the bow spring body, the first and the second collar assembly may move axially relative to the grip ring when in the engaged position.

[0004] A method of using a centralizer is disclosed. The method includes placing the centralizer on the casing. The centralizer includes a grip ring. The method also includes releasing the grip ring to allow the grip ring to contact the casing. The method further includes energizing the grip ring by moving the centralizer in an axial direction relative to the grip ring. Additionally, the method includes allowing the centralizer to rotate and move axially relative to the grip ring and the casing.

[0005] A centralizer for use with a casing in a wellbore is disclosed. The centralizer includes a bow spring body having a plurality of bows. The centralizer further includes a first collar assembly located at a first end of the bow spring body. The centralizer also includes a second collar assembly located at a second end of the bow spring body. Each collar assembly includes a grip ring configured to move from a retracted position to an engaged position and a radial gap between an inner surface of the collar assembly and an outer surface of the casing, wherein the radial gap allows upset ends of the bows to transfer a side load to the grip ring while preventing the bows from contacting the casing when the bows are compressed by a wellbore restriction. The bow spring body, the first collar assembly, and the second collar assembly are configured to move axially relative to the grip ring when the grip ring is in the engaged positionBRIEF DESCRIPTION OF THEDRAWINGS

[0006] The present disclosure may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention. In the drawings:

[0007] FIG. 1 illustrates a side view of a centralizer, according to an embodiment.

[0008] FIG. 2 illustrates an end view of the centralizer, according to an embodiment.

[0009] FIG. 3A illustrates a cross-sectional view of a centralizer in a first (e.g. pre-installed) position, according to an embodiment.

[0010] FIG. 3B illustrates a cross-sectional view of the centralizer in a second position with grip rings deployed, according to an embodiment.

[0011] FIG. 3C illustrates a cross-sectional side view of the centralizer in a third (e.g., engaged) position with grip rings engaged, according to an embodiment.

[0012] FIG. 3D is a sectional view of the centralizer in a fourth position with bows compressed, according to an embodiment.

[0013] FIG. 3E is a sectional view of the centralizer in a fifth position, according to an embodiment.

[0014] FIG. 3F is a sectional view of the centralizer in a sixth position, according to an embodiment.

[0015] FIG. 3G is a sectional view of the centralizer in a seventh position, according to an embodiment.

[0016] FIG. 3H is a sectional view of the centralizer in an eighth (e.g., disengaged) position, according to an embodiment.

[0017] FIG. 4A illustrates a cross-sectional view of a centralizer in a first (e.g. pre-installed) position, according to an embodiment.

[0018] FIG. 4B illustrates a cross-sectional view of the centralizer in a second position with grip rings deployed, according to an embodiment.

[0019] FIG. 4C is a sectional view of the centralizer in a third position, according to an embodiment.

[0020] FIG. 4D is a sectional view of the centralizer in a fourth position, according to an embodiment.

[0021] FIG. 5A illustrates a cross-sectional view of a centralizer in a first (e.g. pre-installed) position, according to an embodiment.

[0022] FIG. 5B illustrates a cross-sectional view of the centralizer in a second position with grip rings deployed, according to an embodiment.

[0023] FIG. 5C illustrates a cross-sectional side view of the centralizer in a third (e.g., engaged) position with grip rings engaged, according to an embodiment.

[0024] FIG. 5D is a sectional view of the centralizer in a fourth position with bows compressed, according to an embodiment.

[0025] FIG. 5E is a sectional view of the centralizer in a fifth position, according to an embodiment.

[0026] FIG. 5F is a sectional view of the centralizer in a sixth position, according to an embodiment.

[0027] FIG. 5G is a sectional view of the centralizer in a seventh (e.g., disengaged) position, according to an embodiment.

[0028] FIG. 6 is an enlarged sectional view of the centralizer, according to an embodiment.

[0029] FIG. 7 illustrates a flowchart of a method for operating a centralizer on a casing, according to an embodiment.

[0030] FIG. 8A illustrates a cross-sectional view of a centralizer in a pre-engaged position, according to an embodiment.

[0031] FIG. 8B illustrates a cross-sectional side view of the centralizer in an engaged position with grip rings engaged, according to an embodiment.DETAILED DESCRIPTION

[0032] The following disclosure describes several embodiments for implementing different features, structures, or functions of the invention. Embodiments of components, arrangements, and configurations are described below to simplify the present disclosure. However, these embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference characters (e.g., numerals) and / or letters in the various embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed in the Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact. It may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the embodiments presented below may be combined in any combination of ways. For example, any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.

[0033] Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names. As such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Additionally, in the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion. Thus, they should be interpreted to mean “including, but not limited to.” All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. In addition, unless otherwise provided herein, “or” statements are intended to be non-exclusive. For example, the statement “A or B” should be considered to mean “A, B, or both A and B.”

[0034] FIG. 1 illustrates a side view of a centralizer 100, according to an embodiment. As described herein, the centralizer 100 includes a first collar assembly 125 with a self-locking mechanism and a second collar assembly 175 with a self-locking mechanism. The centralizer 100 further includes a bow body 150 that includes a plurality of bow springs. The first collar assembly 125 may be connected to one end of the body 150 by welding. The second collar assembly 175 may be connected to another end of the bow body 150 by welding (FIGS. 3A and 3B). Alternatively, the first collar assembly 125, the bow body 150, and the second collar assembly 175 may be made from a single piece (FIG. 5A). Each collar assembly 125, 175 includes a grip ring (not shown) that is held in place by a connection member 75. FIG. 2 illustrates an end view of the centralizer 100, according to an embodiment. As shown, the second collar assembly 175 is connected to the bow body 150.

[0035] FIG. 3A illustrates a cross-sectional view of a centralizer 300 in a first (e.g. pre-installed) position, according to an embodiment. The centralizer 300 is placed on a casing 50. The centralizer 300 includes a first collar assembly 325, a bow spring body 350, and a second collar assembly 375. The first collar assembly 325 and the second collar assembly 375 are welded to the bow spring body 350 at weld 25.

[0036] The first collar assembly 325 will be described herein. The second collar assembly 375 has similar components and functions in a similar manner to the first collar assembly 325. The first collar assembly 325 includes a self-locking mechanism, which comprises a collar body 330 and a grip ring 345 that engages the casing through a wedging action. In the pre-installed position, the grip ring 345 is held in a retracted position within the collar body 330 by a connection member 75, such as a screw. The collar body 330 includes a first shoulder 335 and a second shoulder 340.

[0037] FIG. 3B illustrates a cross-sectional view of the centralizer 300 in a second position with grip rings 345 deployed, according to an embodiment. As shown, the connection members 75 have been removed, which allows the grip ring 345 to move into contact with an outer surface of the casing 50. In other words, the grip ring 345 has moved from a retracted position (FIG. 3A) to an engaged position (FIG. 3B). The grip ring 345 may include a grip profile on an outer surface. The grip profile may comprise wickers, teeth, or serrations that are configured to grip into the outer surface of the casing 50.

[0038] FIG. 3C illustrates a cross-sectional side view of the centralizer 300 in a third position in which the grip ring 345 is engaged, according to an embodiment. External axial applied forces have moved the centralizer 300 in a first axial direction 305. This causes the body 330 to come into contact with the grip ring 345. As shown, the grip ring 345 has engaged with a taper on the inner surface of the body 330. As also shown, the grip ring 345 is fully engaged with the outer surface of casing 50. In other words, the grip profile of the grip ring 345 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 300 are run into a wellbore. Further, the centralizer 300 may move axially relative to the grip ring 345 and the casing 50. The centralizer 300 may also rotate relative to the grip ring 345 and the casing 50.

[0039] FIG. 3D is a sectional view of the centralizer 300 in a fourth position with the bows in the bow spring body 350 compressed, according to an embodiment. As the casing 50 and the centralizer 300 are run into the wellbore in the first axial direction 305, the centralizer 300 may encounter a restriction 10 in the wellbore. This restriction causes the bows in the bow spring body 350 to compress toward the casing 50. As shown, the bows of the bow spring body 350 are closer to the outer surface of the casing 50 in FIG. 3D as comparison to the bows in the body 350 shown in FIG. 3C. As also shown, the grip ring 345 in the second collar assembly 375 has engaged the shoulder 340 in the collar body 330. However, the grip ring 345 in the second collar assembly 375 is free to move in the axial direction 305 due to the grip profile (wicker) orientation.

[0040] FIG. 3E is a sectional view of the centralizer 300 in a fifth position, according to an embodiment. After the centralizer 300 moves through the restriction 10 (FIG. 3D) and into an open area (e.g., open hole), the bows of the bow spring body 350 expand radially outward.

[0041] FIG. 3F is a sectional view of the centralizer 300 in a sixth position, according to an embodiment. The centralizer 300 is under a high axial load as the centralizer 300 moves relative to the casing 50 in the first axial direction 305. As shown, the grip ring 345 has engaged the first shoulder 335. This engagement causes a high axial load on the centralizer 300 as the centralizer moves in the axial direction 305.

[0042] FIG. 3G is a sectional view of the centralizer in a seventh position, according to an embodiment. The grip ring 345 in the first collar assembly 325 has been moved from the engaged position (FIG. 3F) to the retracted position (FIG. 3G). The retraction of the grip ring 345 can be done by placing the connection member 75 in a hole or a slot in the collar body 330. The connection member 75 is inserted until it engages with a hole in the grip ring 345. The connection member 75 is then used to move the grip ring 345 from the engaged position to the retracted position. A similar procedure can be used to move the grip ring 345 in the second collar assembly 375 from the engaged position to the retracted position.

[0043] FIG. 3H is a sectional view of the centralizer 300 in an eighth (e.g., disengaged) position, according to an embodiment. As shown, the grip ring 345 in both the first and second collar assembly 325, 375 are in the retracted position. At this time, the centralizer 300 is disengaged from the casing 50 and may be removed.

[0044] FIG. 4A illustrates a cross-sectional view of a centralizer 400 in a first (e.g. pre-installed) position, according to an embodiment. The centralizer 400 is placed on a casing 50. The centralizer 400 includes a first collar assembly 425, a bow spring body 450, and a second collar assembly 475. The first collar assembly 425 and the second collar assembly 475 are welded to the bow spring body 450 at weld 25.

[0045] The first collar assembly 425 will be described herein. The second collar assembly 475 has similar components and functions in a similar manner to the first collar assembly 425. The first collar assembly 425 includes a self-locking mechanism, which comprises a collar body 430 and a grip ring 445 that engages the casing. In the pre-installed position, the grip ring 445 is held in a retracted position within the collar body 430 by a connection member 75, such as a screw. The collar body 430 includes an inner surface 435 and a shoulder 440. As shown, the shoulder 440 is a portion of the bow spring body 450.

[0046] FIG. 4B illustrates a cross-sectional view of the centralizer in a second position with grip rings deployed, according to an embodiment. As shown, the connection members 75 have been removed. This allows the grip ring 445 to move into contact with an outer surface of the casing 50. In other words, the grip ring 445 has moved from a retracted position (FIG. 4A) to an engaged position (FIG. 4B). The grip ring 445 may include a grip profile, such as wickers, teeth or serrations, on a surface. The grip profile is configured to grip (or bite or penetrate) into the outer surface of the casing 50.

[0047] FIG. 4C is a sectional view of the centralizer 400 in a third position, according to an embodiment. External axial applied forces have moved the centralizer 400 in a first axial direction 405. This causes the inner surface 435 of the body 430 to come into contact with the grip ring 445. As shown, the grip ring 445 has engaged with a taper on the inner surface 435 of the body 430. As also shown, the grip ring 445 is fully engaged with the outer surface of casing 50. This can be accomplished using low to moderate axial load. In other words, the grip profile of the grip ring 445 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 400 are run into a wellbore. Further, the centralizer 400 may move axially relative to the grip ring 445 and the casing 50. The centralizer 400 may also rotate relative to the grip ring 445 and the casing 50.

[0048] FIG. 4D is a sectional view of the centralizer 400 in a fourth position, according to an embodiment. The centralizer 400 is under a high axial load as the centralizer 400 moves relative to the casing 50 in the first axial direction 405. As shown, the grip ring 445 in the first collar assembly 425 has engaged the inner surface 435. The grip ring 445 in the second collar assembly 475 has engaged the shoulder 440. This causes a high axial load on the centralizer 400 as the centralizer moves in the axial direction 405. Further, as shown, a back hook 455 in the first collar assembly 425 has engaged the inner surface 435 of the collar body 430. The back hook 455 is a rearward-facing protrusion on the grip ring 445 that provides additional load resistance under high axial loads.

[0049] The grip ring 445 in the first collar assembly 425 of the centralizer 400 may be moved from the engaged position (FIG. 4D) to the retracted position (FIG. 4A). The retraction of the grip ring 445 can be done by placing the connection member 75 in a hole or a slot in the collar body 430. The connection member 75 is inserted until it engages with a hole in the grip ring 445. The connection member 75 is then used to move the grip ring 445 from the engaged position to the retracted position. A similar procedure can be used to move the grip ring 445 in the second collar assembly 475 from the engaged position to the retracted position.

[0050] FIG. 5A illustrates a cross-sectional view of a centralizer 500 in a first (e.g. pre-installed) position, according to an embodiment. The centralizer 500 is placed on a casing 50. The centralizer 500 includes a first collar assembly 525, a bow spring body 550, and a second collar assembly 575. The first collar assembly 525, the second collar assembly 575 and the bow spring body 550 are a single body. In other words, the first and second collar assemblies 525, 575 are not welded to the bow spring body 550 as shown in centralizers 300, 400. The centralizer 500 may be used in a wellbore that requires a high tolerance centralizer.

[0051] The first collar assembly 525 will be described herein. The second collar assembly 575 has similar components and functions in a similar manner to the first collar assembly 525. The first collar assembly 525 includes a self-locking mechanism, which comprises a collar body 530 and a grip ring 545 that engages the casing through a wedging action. In the pre-installed position, the grip ring 545 is held in a retracted position within the collar body 530 by a connection member 75, such as a screw. The collar body 530 includes a taper 535.

[0052] FIG. 5B illustrates a cross-sectional view of the centralizer 500 in a second position with grip rings 545 deployed, according to an embodiment. As shown, the connection members 75 have been removed, which allows the grip ring 545 to move into contact with an outer surface of the casing 50. In other words, the grip ring 545 has moved from a retracted position (FIG. 5A) to an engaged position (FIG. 5B). The grip ring 545 may include a grip profile, such as wickers, teeth or serrations, on a surface. The grip profile is configured to grip (or bite or penetrate) into the outer surface of the casing 50.

[0053] FIG. 5C illustrates a cross-sectional side view of the centralizer 500 in a third position in which the grip ring 545 is engaged, according to an embodiment. External axial forces have moved the centralizer 500 in a first axial direction 505. This causes the body 530 to come into contact with the grip ring 545. As shown, the grip ring 545 has engaged with the taper 535 on the inner surface of the body 530. As also shown, the grip ring 545 is fully engaged with the outer surface of casing 50 in the engaged position. In other words, the grip profile of the grip ring 545 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 500 are run into a wellbore. Further, the centralizer 500 may move axially relative to the grip ring 545 and the casing 50. The centralizer 500 may also rotate relative to the grip ring 545 and the casing 50.

[0054] FIG. 5D is a sectional view of the centralizer 500 in a fourth position, according to an embodiment. External axial applied forces have moved the centralizer 500 in a second axial direction 510. This causes the body 530 to come into contact with the grip ring 545 in the second collar assembly 575. As shown, the grip ring 545 has engaged with the taper 535 on the inner surface of the body 530. As also shown, the grip ring 545 is fully engaged with the outer surface of casing 50. In other words, the grip profile of the grip ring 545 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 500 are pulled out of the wellbore.

[0055] FIG. 5E is a sectional view of the centralizer 500 in a fifth position with the bows in the bow spring body 550 compressed, according to an embodiment. As the casing 50 and the centralizer 500 are run into the wellbore in the first axial direction 505, the centralizer 500 may encounter a restriction 10. This restriction causes the bows in the bow spring body 550 to compress toward the casing 50. As shown, the bows of the bow spring body 550 are closer to the outer surface of the casing 50 in FIG. 5E as compared to the bows in the body 550 shown in FIG. 5C. As also shown, the grip ring 545 in the second collar assembly 575 has engaged the taper 535 in the collar body 530.

[0056] FIG. 5F is a sectional view of the centralizer 500 in a sixth position, according to an embodiment. The centralizer 500 is under high axial load as the centralizer 500 moves relative to the casing 50 in the first axial direction 505. As shown, the grip ring 545 has engaged the taper 535, thereby inducing high axial stress on the centralizer 500 during axial movement in direction 505. As also shown, a back hook 555 in the first collar assembly 525 has engaged the taper 535 in the collar body 530 under the high axial load. The back hook 555 is a rearward-facing protrusion on the grip ring 545 configured to provide bidirectional load resistance. Under the high axial load, the collar body 530 undergoes plastic deformation. This deformation continues until the back hook 555 achieves full engagement with the collar body 530. Once fully engaged, the back hook 555 creates a load-bearing interface with the collar body 530. This interface prevents relative displacement between the grip ring 545 and the collar body 530 under operational loading.

[0057] FIG. 5G is a sectional view of the centralizer 500 in a seventh (e.g., disengaged) position, according to an embodiment. As shown, the grip ring 545 in both the first and second collar assembly 525, 575 are in the retracted position. At this time, the centralizer 500 is disengaged from the casing 50 and may be removed. The grip ring 545 in the first collar assembly 525 has been moved from the engaged position (FIG. 5F) to the retracted position (FIG. 5G). The retraction of the grip ring 545 can be done by placing the connection member 75 in a hole or a slot in the collar body 530. The connection member 75 is inserted until it engages with a hole in the grip ring 545. The connection member 75 is then used to move the grip ring 545 from the engaged position to the retracted position. A similar procedure can be used to move the grip ring 545 in the second collar assembly 575 from the engaged position to the retracted position.

[0058] FIG. 6 is an enlarged sectional view of the centralizer 500, according to an embodiment. As shown, the bows of the bow body 550 are substantially flat and may contact an outer surface 570 of the casing 50 as the centralizer 500 goes through the restriction 10. During this compression, the bow structure undergoes elastic deflection and potentially plastic deflection as it experiences compressive loading from the wellbore restriction. A side load 560 is generated during compression. The side load 560 represents a radial force vector normal to the longitudinal axis of the centralizer 500. This side load 560 is transferred through the upset ends of the bows into the grip rings 545. From the grip rings 545, the load is transferred to the outer surface of the casing 50. This creates a load path that redirects the reaction forces through the end connections. The radial gap 565 provides a relief area for the loaded bow of the bow body 550. This gap functions as a clearance zone that permits controlled radial deflection of the bow structure. The radial gap 565 maintains contact between the bow upset ends and the grip ring assembly while allowing deflection. Without the radial gap 565 and the transfer of the side load 560, the loaded bow would be overstressed beyond its elastic limit. This overstress would cause the bow to take a permanent set, which is plastic deformation. The plastic deformation would reduce the restoring force of the bow by compromising its elastic recovery characteristics. This would reduce the radial centralization force that maintains standoff distance between the casing outer diameter and the wellbore inner diameter. The radial gap 565 decouples the bow deflection from direct compressive loading against the casing surface. This decoupling allows the upset ends to function as pivot points. These pivot points redistribute bending moments and shear forces away from the mid-span section of the bow. By redistributing these forces, the radial gap 565 preserves the structural integrity and elastic properties of the spring element. This preservation allows the bow to maintain its function throughout multiple compression cycles during wellbore navigation.

[0059] FIG. 7 illustrates a flowchart 700 of a method for operating the centralizer 300, 400, 500 on a casing 50, according to an embodiment. An illustrative order of the method 700 is provided below, however, one or more steps of the method 700 may be performed in a different order, simultaneously, repeated, or omitted. Further, the method 700 could apply to any embodiment described herein. Additionally, the method will be described in relation to the centralizer 300, but it can be applied to centralizers 400, 500, and 800.

[0060] The method 700 may include placing the centralizer on the casing, as at 705. The centralizer 300 shown in FIG. 3A is in the pre-installed position on the casing 50.

[0061] The method 700 may include releasing the grip rings in the centralizer to allow the grip rings to contact the casing, as at 710. The grip rings 345 of the centralizer 300 are released as shown in FIG. 3B.

[0062] The method 700 may include moving the centralizer in an axial direction relative to grip rings to energize the grip rings on the casing, as at 715. The centralizer 300 is moved in an axial direction 305 in FIG. 3C to energize the grip ring 345.

[0063] The method 700 may include allowing the centralizer to rotate and move axially relative to the grip rings, as at 720. The centralizer 300 is able to rotate and move axially to the grip ring 345 as shown in FIG. 3E.

[0064] The method 700 may include de-activating the grip ring to allow the centralizer to be removed from the casing, as at 725. The grip ring 345 of centralizer 300 is de-activated in FIG. 3H and the centralizer 300 is able to be removed from the casing 50.

[0065] FIG. 8A illustrates a cross-sectional view of a centralizer 800 in a pre-engaged position, according to an embodiment. The centralizer 800 is placed on a casing 50. The centralizer 800 includes a first collar assembly 825, a bow spring body 850, and a second collar assembly 875. The first collar assembly 825, the second collar assembly 875 and the bow spring body 850 are a single body. In other words, the first and second collar assemblies 825, 875 are not welded to the bow spring body 850 as shown in centralizers 300, 400. The centralizer 800 may be used in a wellbore that requires a high tolerance centralizer.

[0066] The first collar assembly 825 will be described herein. The second collar assembly 875 has similar components and functions in a similar manner to the first collar assembly 825. The first collar assembly 825 includes a self-locking mechanism, which comprises a collar body 830 and a grip ring 845 that engages the casing 50 through a wedging action. In the pre-installed position, the grip ring 845 is held in a retracted position within the collar body 830 by a connection member 75, such as a screw.

[0067] The collar body 830 includes a ramp 840 and a shoulder 835. The ramp 840 may have an angle of between 5 degrees and 25 degrees relative to a longitudinal axis of the collar body 830. In some embodiments, the ramp angle is between 10 degrees and 20 degrees. The ramp 840 may have an axial length of between 0.25 inches and 2.0 inches. In some embodiments, the axial length is between 0.5 inches and 1.5 inches. The shoulder 835 may extend radially inward from the inner surface of the collar body 830. The radial extension distance may be between 0.05 inches and 0.5 inches. In some embodiments, the radial extension is between 0.1 inches and 0.3 inches. The shoulder 835 may be formed on the collar body 830 by using a roller. In this method, the roller applies radial force to the inner surface of the collar body 830 while the collar body 830 is rotated. This plastically deforms the material to create the shoulder 835 in a controlled manner. Alternatively, the shoulder 835 may be formed on the collar body 830 by using a swage. In this method, a mandrel or die is forced through or into the collar body 830. This radially displaces the material and forms the shoulder 835 through cold working of the metal.

[0068] FIG. 8B illustrates a cross-sectional view of the centralizer 800 in a second position with grip rings 845 deployed, according to an embodiment. As shown, the connection members 75 have been removed, which allows the grip ring 845 to move into contact with an outer surface of the casing 50. In other words, the grip ring 845 has moved from a retracted position (FIG. 8A) to an engaged position (FIG. 8B). The grip ring 845 may include a grip profile, such as wickers, teeth or serrations, on a surface. The grip profile is configured to grip (or bite or penetrate) into the outer surface of the casing 50.

[0069] External axial forces have moved the centralizer 800 in a first axial direction 805. This causes the body 830 to come into contact with the grip ring 845. As shown, the grip ring 845 has moved along the ramp 840. A nose 885 on the grip ring 845 is engaged with the shoulder 835 on the inner surface of the body 830. The nose 885 may extend radially outward from an outer surface of the grip ring 845 by a distance of between 0.05 inches and 0.5 inches. In some embodiments, this distance is between 0.1 inches and 0.3 inches. The nose 885 may have an axial length of between 0.1 inches and 1.0 inches. In some embodiments, the axial length is between 0.2 inches and 0.6 inches. When engaged, the nose 885 may contact the shoulder 835 over an engagement depth of between 0.05 inches and 0.4 inches. In some embodiments, the engagement depth is between 0.08 inches and 0.25 inches. This engagement provides a mechanical lock that resists axial movement. As also shown, the grip ring 845 is fully engaged with the outer surface of casing 50 in the engaged position. In other words, the grip profile of the grip ring 845 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 800 are run into a wellbore. Further, the centralizer 800 may move axially relative to the grip ring 845 and the casing 50. The centralizer 800 may also rotate relative to the grip ring 845 and the casing 50.

[0070] Similar to other embodiments described herein (i.e., FIG. 5D) external axial applied forces may move the centralizer 800 in a second axial direction, which causes the body 830 to come into contact with the grip ring 845 in the second collar assembly 875. The nose 885 on the grip ring 845 has engaged with the shoulder 835 on the inner surface of the body 830. The grip ring 845 is fully engaged with the outer surface of casing 50. In other words, the grip profile of the grip ring 845 has gripped (or bitten or penetrated) into the outer surface of the casing 50. The external axial applied forces may occur as the casing 50 and the centralizer 800 are pulled out of the wellbore.

[0071] As the casing 50 and the centralizer 800 are run into the wellbore in the first axial direction 805, the centralizer 800 may encounter a restriction, which causes the bows in the bow spring body 850 to compress toward the casing 50. The bows of the bow spring body 850 may be closer to the outer surface of the casing 50.

[0072] The centralizer 800 is under a high axial load as the centralizer 800 moves relative to the casing 50 in the first axial direction 805. The grip ring 845 has moved along the ramp 840. The nose 885 on the grip ring 845 has engaged the shoulder 835. This causes a high axial load on the centralizer 800 as the centralizer moves in the axial direction 805. As also shown, a back hook 855 (a rearward-facing protrusion on the grip ring 845) in the first collar assembly 825 is engaged with the ramp 840 in the collar body 830 under the high axial load. The nose on the grip ring 845 is also engaged with the shoulder 835 in the collar body 830. The collar body 830 plastically deforms until the back hook 855 is engaged with the collar body 830.

[0073] The grip ring 845 in both the first and second collar assembly 825, 875 may be moved to the retracted position. At this time, the centralizer 800 is disengaged from the casing 50 and may be removed. The grip ring 845 in the first collar assembly 825 has been moved from the engaged position to the retracted position (similar to FIG. 8A). The retraction of the grip ring 845 can be done by placing the connection member 75 in a hole or a slot in the collar body 830. The connection member 75 is inserted until it engages with a hole in the grip ring 845. The connection member 75 is then used to move the grip ring 845 from the engaged position to the retracted position. A similar procedure can be used to move the grip ring 845 in the second collar assembly 875 from the engaged position to the retracted position.

[0074] As used herein, the terms “inner” and “outer”; “up” and “down”; “upper” and “lower”; “upward” and “downward”; “above” and “below”; “inward” and “outward”; “uphole” and “downhole”; and other like terms as used herein refer to relative positions to one another and are not intended to denote a particular direction or spatial orientation. The terms “couple,”“coupled,”“connect,”“connection,”“connected,”“in connection with,” and “connecting” refer to “in direct connection with” or “in connection with via one or more intermediate elements or members.”

[0075] The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Examples

Embodiment Construction

[0032]The following disclosure describes several embodiments for implementing different features, structures, or functions of the invention. Embodiments of components, arrangements, and configurations are described below to simplify the present disclosure. However, these embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference characters (e.g., numerals) and / or letters in the various embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed in the Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact. It may also include embodiments in which additional features may be form...

Claims

1. A centralizer for use with a casing, comprising:a bow spring body having a plurality of bows;a first collar assembly located at a first end of the bow spring body; anda second collar assembly located at a second end of the bow spring body, wherein each collar assembly includes a grip ring that is configured to move from a retracted position to an engaged position, and wherein the bow spring body, the first and the second collar assembly may move axially relative to the grip ring when in the engaged position.

2. The centralizer of claim 1, wherein the bow spring body, the first and the second collar assembly may rotate relative to the grip ring when in the engaged position.

3. The centralizer of claim 1, wherein the bow spring body, the first and the second collar assembly are made from a single piece.

4. The centralizer of claim 1, wherein the first and the second collar assembly are welded to the ends of bow spring body.

5. The centralizer of claim 1, further comprising a connection member that is configured to hold the grip ring in the retracted position.

6. The centralizer of claim 1, wherein the first collar assembly includes a first shoulder that is configured to engage the grip ring.

7. The centralizer of claim 6, wherein the first collar assembly includes a second shoulder that is configured to engage the grip ring.

8. The centralizer of claim 7, wherein the first shoulder and the second shoulder are positioned proximate each end of the first collar.

9. The centralizer of claim 6, wherein the first shoulder is formed in the first collar assembly by moving a swage member through the first collar.

10. The centralizer of claim 1, wherein the grip ring has a back hook on an outer surface that is configured to engage the first collar to transfer a load from the centralizer to the casing.

11. The centralizer of claim 1, wherein each collar assembly includes a radial gap between an inner surface of the collar assembly and the outer surface of the casing, wherein the radial gap allows upset ends of the bows to transfer a side load to the grip rings while preventing the bows from contacting the casing when the bows are compressed by a wellbore restriction.

12. A method of using a centralizer on a casing, the method comprising:placing the centralizer on the casing, wherein the centralizer includes bows and a grip ring;releasing the grip ring to allow the grip ring to contact the casing;energizing the grip ring by moving the centralizer in an axial direction relative to the grip ring; andallowing the centralizer to rotate and move axially relative to the grip ring and the casing.

13. The method of claim 12, further comprising deactivating the grip ring to allow the centralizer to be removed from the casing.

14. The method of claim 12, further comprising:subjecting the centralizer to an axial load as the centralizer moves relative to the casing;engaging a back hook on the grip ring with a collar body of the collar assembly;plastically deforming the collar body until the back hook achieves full mechanical engagement with the collar body; andcreating a load-bearing engagement interface that resists axial movement and provides bidirectional load resistance.

15. A centralizer for use with a casing in a wellbore, comprising:a bow spring body having a plurality of bows;a first collar assembly located at a first end of the bow spring body; anda second collar assembly located at a second end of the bow spring body,wherein each collar assembly includes:a grip ring configured to move from a retracted position to an engaged position; anda radial gap between an inner surface of the collar assembly and an outer surface of the casing, wherein the radial gap allows upset ends of the bows to transfer a side load to the grip ring while preventing the bows from contacting the casing when the bows are compressed by a wellbore restriction; andwherein the bow spring body, the first collar assembly, and the second collar assembly are configured to move axially relative to the grip ring when the grip ring is in the engaged position.

16. The centralizer of claim 15, wherein the grip ring includes a back hook on an outer surface that is configured to engage with the collar assembly under axial loading to transfer a load from the centralizer to the casing and provide bidirectional load resistance.

17. The centralizer of claim 15, wherein each collar assembly includes a shoulder formed on an inner surface of the collar assembly by using a swage, wherein the swage radially displaces material of the collar assembly to form the shoulder through cold working.

18. The centralizer of claim 15, wherein the bow spring body, the first and the second collar assembly are made from a single piece.

19. The centralizer of claim 15, wherein the first and the second collar assembly are welded to the ends of bow spring body.

20. The centralizer of claim 15, wherein the grip ring includes wickers, teeth, or serrations on a surface configured to grip into the outer surface of the casing when the grip ring is in the engaged position.

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