HIGH EXPANSION CENTRALIZER

Abstract

A system and method of centralizing a tool. The centralizer has a mandrel with a static housing and a dynamic housing positioned about the mandrel. A plurality of V segments, each V segment coupled to the static housing at a first end and the dynamic housing at a second end and shiftable from an undeployed position to a deployed position to centralize the tool. A piston assembly operable to shift the dynamic housing to shift the plurality of V segments from the undeployed position to the deployed position, a retention mechanism operable to prevent the plurality of V segments from shifting from the deployed position to the undeployed position. A flexible sleeve on the outer surface of the plurality of V segments that contacts the wellbore when the V segments are actuated.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present document is based on and claims priority to Indian Provisional Application Serial No.: 202221071948, filed Dec. 13, 2022, which is incorporated herein by reference in its entirety.

BACKGROUND

Hydrocarbons produced from a subterranean formation oftentimes have sand or other particulates disposed therein. As the sand is undesirable to produce, many techniques exist for reducing the sand content in the hydrocarbons. Gravel packing is one technique used to filter and separate the sand from the hydrocarbons in a wellbore. Gravel packing generally involves pumping a gravel slurry, including gravel dispersed within a carrier fluid, down a work string and into the annulus formed between a completion assembly and the wall of the wellbore. The gravel is used to filter and separate the sand from the hydrocarbons as the hydrocarbons flow from the formation, into a completion assembly, and up to the surface.

One or more packers are oftentimes set or actuated prior to gravel packing. Upon actuation, the packers expand radially outward into contact with the wall of the wellbore to isolate different layers or zones of the formation. Isolating the different zones prevents the cross-flow of fluids (e.g., hydrocarbon fluids such as oil or gas) between the different zones and reduces the amount of water produced from the formation.

Centralizers are known for centering various well tools in a wellbore. A centralizer will ensure a gravel packing tool is positioned in the center of the wall. To ensure efficiency of the gravel packing process, it is desirable to have space between the wall of the wellbore and tubular within the wellbore creating an annulus. The annulus will allow the gravel slurry to flow between the tubular and the wall of the wellbore.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a centralizer comprising: a mandrel; a static housing positioned about the mandrel and comprising a first lug extending between the static housing and the mandrel to prevent relative rotational and axial movement between the static housing and the mandrel; a dynamic housing positioned about the mandrel and comprising a second lug extending between the dynamic housing and the mandrel to prevent relative rotational movement and allow limited relative axial movement between the dynamic housing and the mandrel; a plurality of V segments, each V segment coupled to the static housing at a first end and the dynamic housing at a second end and shiftable from an undeployed position to a deployed position; a piston assembly operable to shift the dynamic housing to shift the plurality of V segments from the undeployed position to the deployed position; and a retention mechanism operable to prevent the plurality of V segments from shifting from the deployed position to the undeployed position. the retention mechanism is a ratchet mechanism.

According to another aspect of the present invention, the V segment has a first linkage and a second linkage connected at a pivot joint. The first linkage is pinned to the static housing and the second linkage pinned to the dynamic housing.

According to another aspect of the present invention, the piston assembly comprises a piston in a chamber created by the mandrel, a piston housing and the dynamic housing; and the mandrel has a port for the entry of hydraulic fluid into the chamber. The centralizer of claim 6, wherein the piston assembly comprises multiple piston assembly and each piston assembly is associated with a V segment; and each V segments can be actuated radially to various lengths to accommodate the irregularity of an uncased wellbore.

The centralizer of claim 1, further comprising a flexible sleeve on the outer surface of the plurality of V segments, wherein when the plurality of V segments are actuated the flexible sleeve contacts the wellbore. The flexible sleeve is a pliable shroud that shields the plurality of V segments and protects the wellbore when the plurality of V segments are actuated.

According to another aspect of the present invention, a method comprising: positioning a centralizer within a wellbore; axially shifting a dynamic housing of the centralizer relative to a static housing of a centralizer via a piston to shift a plurality of V segments coupled to the static housing at a first end and the dynamic housing at a second end from an undeployed position to a deployed position; and retaining the V segments in the deployed position via a retention mechanism.

According to another aspect of the present invention, hydraulic fluid is conveyed through a port in the mandrel to enter a chamber created by created by a mandrel, a piston housing and the dynamic housing to apply a hydraulic force to the piston. The hydraulic force shears a shear screw causing axial movement of the piston within the chamber to contact the dynamic housing. Contact with the dynamic housing causes the dynamic housing to axial move towards the static housing actuating the plurality of V segments.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various described technologies. The drawings are as follows:

FIG. 1 is a schematic view of a well system according to one or more embodiments of the present disclosure;

FIG. 2 is a side view of a high expansion centralizer in an undeployed position according to one or more embodiments of the present disclosure;

FIG. 3 is a cross-sectional view of the high expansion centralizer of FIG. 2 in an undeployed position;

FIG. 4 is a cross-sectional view of the high expansion centralizer of FIG. 2 in a deployed position; and

FIG. 5 is a cross-sectional view of a high expansion centralizer with a movable shroud attached at one end that is located on the outer surface of a V segment.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that that embodiments of the present disclosure may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.

In the specification and appended claims: the terms “connect,” “connection,” “connected,” “in connection with,” “connecting,” “couple,” “coupled,” “coupled with,” and “coupling” are used to mean “in direct connection with” or “in connection with via another element.” As used herein, the terms “up” and “down,” “upper” and “lower,” “upwardly” and “downwardly,” “upstream” and “downstream,” “uphole” and “downhole,” “above” and “below,” and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the disclosure.

Referring now to FIG. 1, FIG. 1 is a well system 100 according to one or more embodiments of the present disclosure. The well system 100 includes a wellbore 102 having a deviated wellbore section 104 extending into a formation 106 containing hydrocarbon fluids. Depending on the application, the wellbore 102 may comprise one or more deviated wellbore sections 104, e.g. horizontal wellbore sections, which may be cased or un-cased. In the example illustrated, a tubing string 108 is deployed downhole into wellbore 102 and comprises a downhole well completion system 110 deployed in the deviated, e.g. horizontal, wellbore section 104.

The downhole well completion 110 system may be constructed to facilitate production of well fluids and/or injection of fluids. By way of example, the downhole well completion 110 system may comprise at least one sand screen joint 112, e.g. a plurality of screen assemblies 112. Each sand screen joint 112 may include a shroud, e.g. a sand screen, 114 that cover a screen filter through which fluid may enter the corresponding sand screen joint 112 for production to a suitable location, e.g. a surface location. For example, hydrocarbon well fluids may flow from formation 106, into wellbore 102, and into the screen assemblies 112 via the shrouds 114. In some embodiments, the downhole well completion system 110 also may comprise a plurality of packers 116 which may be used to isolate sections or zones 118 along the wellbore 102.

The completion system may also include one or more centralizers 120, as described in more detail below. The centralizer to helps prevent damage to the completion system 110 from contacting the wellbore wall as the completion system 110 travels downhole. The centralizer may also help prevent damage to the sealing element of the packer 116 during setting, which can result from uneven loading on the sealing element due to the position of the packer 116 within the wellbore 102.

Turning now to FIGS. 2 and 3, FIGS. 2 and 3 is a side view and a cross-sectional view of a high expansion centralizer 220 in an undeployed position, respectively, according to one or more embodiments of the present disclosure. The high expansion centralizer 220 is positioned about a mandrel 8 and includes a static housing 1 with an anti-rotation and bearing lug 2, a dynamic housing 6, and a plurality of inverted V segments 3. The anti-rotation and bearing lug 2 is positioned in an aperture in the static housing. The anti-rotation and bearing lug 2 prevents relative axial and rotational movement between the anti-rotation and bearing lug 2 and the mandrel 8. The dynamic housing 6 is prevented from rotating about the mandrel 8 via an anti-rotation lug 5 to prevent twisting of V segments 3 during deployment. The anti-rotation lug 5 further extends into a slot on the mandrel 8 to allow for relative axial movement between the mandrel 8 and the dynamic housing 6.

The outer surface of the plurality of V segment 3 is surrounded by a flexible sleeve 11. The flexible sleeve 11 is a pliable material that deforms once the V segments 3 is deployed. The flexible sleeve 11 may comprise a polymeric material, such as polytetrafluoroethylene (PTFE), an elastomer and/or the like. The flexible sleeve 11 as a shroud protecting the plurality of V segment 3 while the tool is lowered into the wellbore 102. The flexible sleeve 11 protects the wall of wellbore 102 when the plurality of V segment 3 are actuated. The flexible sleeve 11 will contact the wall of the wellbore 102 preventing damage to the wellbore wall. The flexible sleeve 11 can have two fixed connections on opposite sides of the V segment as shown in FIGS. 3-4. In another embodiment, the flexible sleeve 11 can have only one fixed connection 12, as shown in FIG. 5. The one fixed connection will ensure that the flexible sleeve 11 can move radially once the V segment 3 are actuated.

The inverted V segment 3 consists of two linkages. A first linkage is pinned to the static housing 1 and a second linkage pinned to the dynamic housing 6. The first linkage and second linkage are connected at a pivot joint. As discussed below, axial movement of the dynamic housing 6 towards the static housing 1 causes the first linkage and second linkage to pivot radially outwards away from the mandrel 8 into a set configuration. A retention mechanism, such as a ratchet mechanism 4, is positioned within the dynamic housing 6 and includes ratchet segments, springs, and cap screws to prevent the V segment 3 from retracting once it is set. In one or more embodiments, an individual ratchet mechanism 4 is used to allow each inverted V segment 3 to radially deploy separately to accommodate the irregularity and ovality of the wellbore 102. In other embodiments, a single rachet type mechanism may be used for all V segments 3.

The high expansion centralizer 220 further includes a piston assembly. The piston assembly includes a piston 9 in a chamber created by the mandrel 8, a piston housing 7 and the dynamic housing 6. A shear screws 10 are used to couple the piston 9 to the dynamic housing 6. The mandrel 8 has a port that allows hydraulic fluid to enter the chamber creating hydraulic pressure utilized to move the piston 9. In one embodiment, one piston 9 can control the actuation of all the V segments 3. In another embodiment, each V segment 3 will have a separate piston assembly with a piston 9 that controls the actuation of each V segment 3. Each piston 9 will be coupled to the dynamic housing 6 with a shear screw 10. Each V segments 3 can be actuated radially to various lengths to accommodate the irregularity of an uncased wellbore 102.

Operation of the centralizer 220 will now be discussed. Hydraulic fluid is conveyed through a port in the mandrel 8. The hydraulic fluid will enter the chamber. A hydraulic force is applied to the piston by the hydraulic fluid. When a requisite amount of hydraulic force is applied to the piston 9 the shear screw 10 will shear causing axial movement of the piston 9 within the chamber. The piston 9 will contact the dynamic housing 6 causing the dynamic housing 6 to slide axial towards the static housing 1, as shown in FIG. 4. Moving the dynamic housing 6 towards the static housing will start the deployment of the V segments 3. The second linkage associated with the dynamic housing 6 will move towards the first linkage causing the first and second linkage to extend radially towards the wellbore wall. The flexible sleeve 11 on the outer surface of the V segments 3 will contact the wall of the wellbore 102. Additionally, when the piston 9 contacts the dynamic housing 6 the ratchet mechanism 4 will be engaged. The ratchet mechanism will only allow axial movement of the dynamic housing 6 towards the static housing land stopping movement in the opposite axial direction thereby preventing retraction V segments 3.

Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.

Most centralizers are designed such that they can operate in a large range of wellbore sizes. As the centralizers expand or contract radially to accommodate changes in the size of the wellbore, their centralizing forces may vary.

Claims

1. A centralizer comprising:

a mandrel;

a static housing positioned about the mandrel;

a dynamic housing positioned about the mandrel;

a plurality of V segments, each V segment coupled to the static housing at a first end and the dynamic housing at a second end and shiftable from an undeployed position to a deployed position;

a piston assembly operable to shift the dynamic housing to shift the plurality of V segments from the undeployed position to the deployed position; and

a retention mechanism operable to prevent the plurality of V segments from shifting from the deployed position to the undeployed position.

2. The centralizer of claim 1, wherein the V segment has a first linkage and a second linkage connected at a pivot joint.

3. The centralizer of claim 3, wherein the first linkage is pinned to the static housing and the second linkage pinned to the dynamic housing.

4. The centralizer of claim 1, wherein the static housing comprising a first lug extending between the static housing and the mandrel to prevent relative rotational and axial movement between the static housing and the mandrel.

5. The centralizer of claim 1, wherein the dynamic housing comprising a second lug extending between the dynamic housing and the mandrel to prevent relative rotational movement and allow limited relative axial movement between the dynamic housing and the mandrel.

6. The centralizer of claim 1, wherein the piston assembly comprises a piston in a chamber created by the mandrel, a piston housing and the dynamic housing; and the mandrel has a port for the entry of hydraulic fluid into the chamber.

7. The centralizer of claim 6, wherein the piston assembly comprises multiple piston assembly and each piston assembly is associated with a V segment; and each V segments can be actuated radially to various lengths to accommodate the irregularity of an uncased wellbore.

8. The centralizer of claim 1, wherein the retention mechanism is a ratchet mechanism.

9. The centralizer of claim 1, further comprising a flexible sleeve on the outer surface of the plurality of V segments, wherein when the plurality of V segments are actuated the flexible sleeve contacts the wellbore.

10. A method of centralizing a tool comprising:

positioning a centralizer within a wellbore;

axially shifting a dynamic housing of the centralizer relative to a static housing of a centralizer via a piston to shift a plurality of V segments coupled to the static housing at a first end and the dynamic housing at a second end from an undeployed position to a deployed position; and

retaining the V segments in the deployed position via a retention mechanism.

11. The centralizer of claim 9, wherein the flexible sleeve is a pliable shroud that shields the plurality of V segments and protects the wellbore when the plurality of V segments are actuated.

12. The method of claim 11, wherein hydraulic fluid is conveyed through a port in the mandrel to enter a chamber created by created by a mandrel, a piston housing and the dynamic housing to apply a hydraulic force to the piston.

13. The method of claim 12, wherein the hydraulic force shears a shear screw causing axial movement of the piston within the chamber to contact the dynamic housing.

14. The method of claim 13, wherein contact with the dynamic housing causes the dynamic housing to axial move towards the static housing actuating the plurality of V segments.

15. The method of claim 14, wherein actuating the plurality of V segments comprises moving the plurality of V segments radially towards a wellbore.

16. The method of claim 11, further comprising a flexible sleeve on the outer surface of the plurality of V segments, wherein the plurality of V segments are actuated the flexible sleeve contacts the wellbore.

17. The method of claim 11, further comprising a retention mechanism operable to prevent the plurality of V segments from shifting from the deployed position to the undeployed position.

18. The method of claim 17, wherein the retention mechanism is a ratchet mechanism.