Deployment system for downhole packer

Abstract

A downhole tool includes a base pipe defining a base pipe passageway, a centralizer coupled to the base pipe, a seal coupled to the base pipe, and a two-stage deployment system configured to deploy the centralizer and the seal. The two-stage deployment system includes a centralizer piston disposed about the base pipe and coupled to the base pipe via a first shear mechanism having a first shear limit. The two-stage deployment system includes a seal piston coupled to the centralizer piston via a second shear mechanism having a second shear limit greater than the first shear limit. The base pipe defines a first port through which pressure from the base pipe passageway is configured to activate the centralizer piston. The base pipe defines a second port through which the pressure is configured to activate the seal piston separately from the activation of the centralizer piston.

Description

IS24.0123A-WO-PCTDEPLOYMENT SYSTEM FOR DOWNHOLE PACKER CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No.63 / 748,200, titled STAGED CENTRALIZER DEPLOYMENT FOR AN OPEN HOLE PACKER, filed January 22, 2025, which is hereby incorporated by reference in its entirety.BACKGROUND

[0002] Open hole packers are deployed in wellbores to provide zonal isolation within subterranean formations, and such packers typically include centralizing mechanisms to position the packer within the wellbore and sealing mechanisms to create a fluid-tight barrier against the wellbore wall. In conventional packer designs, an activation port may be used to set a sealing element directly, which can be suitable for simpler element seals that do not require precise positioning prior to engagement. However, when more complex sealing configurations are employed, such as cup seals with larger expansion ratios, the deployment of the centralizing and sealing mechanisms can affect the performance and reliability of the packer assembly. Accordingly, there exists a general interest in packer deployment systems that can accommodate various sealing configurations and deployment sequences within open hole environments.SUMMARY

[0003] According to an aspect of the present disclosure, a downhole tool is provided.The downhole tool includes a base pipe defining a base pipe passageway. The downhole tool includes a centralizer coupled to the base pipe. The downhole tool includes a seal coupled to the base pipe. The downhole tool includes a two-stage deployment system configured to deploy the centralizer and the seal. The two-stage deployment system includes a centralizer piston disposed about the base pipe and coupled to the base pipe via a first shear mechanism having a first shear limit. The two-stage deployment system includes a seal piston coupled to the centralizer piston via a second shear mechanism having a second shear limit greater than the first shear limit. The base pipe defines a first port through which pressure from the base pipe passageway is configured to activate the1SLB-PrivateIS24.0123A-WO-PCTcentralizer piston. The base pipe defines a second port through which the pressure is configured to activate the seal piston separately from the activation of the centralizer piston.

[0004] According to other aspects of the present disclosure, the downhole tool may include one or more of the following features. The first port may provide fluid communication between the base pipe passageway and a volume between the base pipe and the centralizer piston. The second port may provide fluid communication between the base pipe passageway and the volume between the base pipe and the seal piston. The downhole tool may further include a stop mechanism configured to prevent the centralizer piston from travelling beyond a predetermined distance relative to the base pipe. The centralizer piston may be configured to contact the stop mechanism upon deployment of the centralizer. The downhole tool may further include a ratchet mechanism configured to prevent the seal piston from moving after the seal is deployed. The two-stage deployment system may be configured to deploy the centralizer prior to deploying the seal. The second port may be configured to be uncovered after the centralizer has been deployed. The first port may be defined in a first plane passing through a central axis of the base pipe and the second port may be defined in a second plane passing through the central axis, the second plane different than the first plane. The first port may be configured to be uncovered before the second port during an operation of the two-stage deployment system. The first shear mechanism may include a first shear screw coupling the centralizer piston to the base pipe.The second shear mechanism may include a second shear screw coupling the seal piston to the centralizer piston. The second shear screw may be configured to shear after the first shear screw has sheared during an operation of the two-stage deployment system.

[0005] According to another aspect of the present disclosure, a downhole tool string is provided. The downhole tool string includes a base pipe defining a base pipe passageway. The downhole tool string includes a centralizer. The downhole tool string includes a seal. The downhole tool string includes a centralizer piston surrounding the base pipe and coupled to the centralizer. The centralizer piston is coupled to the base pipe via a first shear screw. The base pipe defines a centralizer activation port fluidly coupling the base pipe passageway to a volume between the base pipe and the centralizer piston. The downhole tool string includes a seal piston coupled to the seal. The seal piston is coupled2SLB-PrivateIS24.0123A-WO-PCTto the centralizer piston via a second shear screw. The base pipe defines a seal activation port fluidly coupling the base pipe passageway to the volume between the base pipe and the seal piston.

[0006] According to other aspects of the present disclosure, the downhole tool string may include one or more of the following features. The centralizer activation port and the seal activation port may be offset radially about a circumference of the base pipe. The first shear screw may have a first shear limit and the second shear screw may have a second shear limit greater than the first shear limit. The first shear screw may be configured to shear upon deployment of the centralizer, thereby allowing the centralizer piston to move relative to the base pipe. The second shear screw may be configured to shear after the first shear screw has sheared and the seal activation port has been uncovered.

[0007] According to another aspect of the present disclosure, a two-stage deployment mechanism for a downhole centralizer and a downhole seal is provided. The two-stage deployment mechanism includes a base pipe defining a base pipe passageway, a centralizer activation port, and a seal activation port. The two-stage deployment mechanism includes a centralizer piston disposed about the base pipe and coupled to the downhole centralizer.The two-stage deployment mechanism includes a seal piston disposed about the base pipe and coupled to the downhole seal. The two-stage deployment mechanism includes a first configuration in which the centralizer activation port and the seal activation port are occluded, the centralizer piston is disposed at an un-deployed centralizer position relative to the base pipe, and the seal piston is disposed at a first position relative to the centralizer piston. The two-stage deployment mechanism includes a second configuration in which the centralizer activation port is open and the seal activation port is occluded, the centralizer piston is disposed at a deployed centralizer position relative to the base pipe, and the seal piston is disposed at the first position relative to the centralizer piston. The two-stage deployment mechanism includes a third configuration in which the seal activation port is open, the centralizer piston is disposed at the deployed centralizer position relative to the base pipe, and the seal piston is disposed at a second position relative to the centralizer piston.3SLB-PrivateIS24.0123A-WO-PCT

[0008] According to other aspects of the present disclosure, the two-stage deployment mechanism may include one or more of the following features. The two-stage deployment mechanism may further include a stop mechanism configured to prevent the centralizer piston from travelling beyond a predetermined distance relative to the base pipe in the second configuration. The centralizer piston may be configured to contact the stop mechanism upon deployment of the downhole centralizer. The two-stage deployment mechanism may further include a ratchet mechanism configured to prevent the seal piston from moving after the downhole seal is deployed in the third configuration.BRIEF DESCRIPTION OF FIGURES

[0009] In order to describe the manner in which the above-recited and other features of the disclosure can be obtained, a more particular description will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. While some of the drawings may be schematic or exaggerated representations of concepts, at least some of the drawings may be drawn to scale. Understanding that the drawings depict some example embodiments, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0010] FIG. 1 depicts a schematic view of a system for deploying a tool string in a wellbore, according to aspects of the present disclosure;

[0011] FIG. 2A illustrates a cross-sectional view of a two-stage deployment system in an initial configuration, according to an embodiment;

[0012] FIG. 2B illustrates a cross-sectional view of the two-stage deployment system of FIG. 2A in an intermediate configuration, according to an embodiment;

[0013] FIG. 2C illustrates a cross-sectional view of the two-stage deployment system of FIG. 2A in a deployed configuration, according to an embodiment;

[0014] FIG. 3 illustrates an isometric view of a base pipe showing activation ports, according to aspects of the present disclosure;4SLB-PrivateIS24.0123A-WO-PCT

[0015] FIG. 4 illustrates a cross-sectional view of a two-stage deployment system showing internal components, according to aspects of the present disclosure;

[0016] FIG. 5 illustrates a cross-sectional view of a two-stage deployment system with a centralizer, according to an embodiment;

[0017] FIG. 6A illustrates a cross-sectional view of a two-stage deployment system in an initial configuration, according to aspects of the present disclosure;

[0018] FIG. 6B illustrates a cross-sectional view of the two-stage deployment system of FIG. 6A, according to an embodiment;

[0019] FIG. 7A illustrates a cross-sectional view of a two-stage deployment system after centralizer deployment, according to aspects of the present disclosure; and

[0020] FIG. 7B illustrates a cross-sectional view of the two-stage deployment system of FIG. 7A with an uncovered seal activation port, according to an embodiment.DETAILED DESCRIPTION

[0021] The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein.

[0022] Downhole tools may be deployed in wellbores to perform various operations within subterranean formations. A downhole tool may include a base pipe defining a base pipe passageway, a centralizer coupled to the base pipe, a seal coupled to the base pipe, and a two-stage deployment system configured to deploy the centralizer and the seal. The base pipe may provide structural support for the downhole tool and may define an internal passageway through which fluids may flow during operations. The centralizer may be configured to position the downhole tool within a wellbore, and the seal may be configured to create a seal between the downhole tool and a surrounding formation or casing.

[0023] In some embodiments, the seal may include a cup seal design. Cup seals may be complex and expansive in nature, and such seal designs may require the centralizer to be deployed before the seal is activated. The two-stage deployment system may address5SLB-PrivateIS24.0123A-WO-PCTthe problem of deploying the centralizing mechanism independently before the sealing mechanism. When using complex and expansive seal designs such as cup seals, deploying the centralizer before the seal may help ensure proper positioning of the downhole tool prior to sealing operations.

[0024] The two-stage deployment system may be configured for use with a large expansion open hole packer. In large expansion open hole packer applications, centralizing the packer before activating the sealing mechanism may be beneficial. The two-stage deployment system may enable sequential deployment where the centralizer deploys first, followed by independent activation of the seal. This staged deployment approach may accommodate the operational requirements of complex seal designs that benefit from proper centralization prior to seal engagement.

[0025] Referring to FIG. 1, a system 100 for deploying a tool string in a wellbore is shown. The system 100 may include a rig 104 positioned at a surface location. The rig 104 may be connected to a controller 106 and processing equipment 107. The controller 106 may be configured to manage operations associated with the system 100, and the processing equipment 107 may be configured to process data or materials associated with downhole operations.

[0026] A wireline 108 may extend from the rig 104 downward into a wellbore 102.The wellbore 102 may pass through subterranean formations 109 and may include a vertical section that transitions into a horizontal section 118. The wireline 108 may provide a communication and support pathway between the rig 104 and downhole components positioned within the wellbore 102.

[0027] With continued reference to FIG. 1, a tool string 110 may be positioned within the horizontal section 118 of the wellbore 102. The tool string 110 may include a centralizer 112, a first seal 114a, a second seal 114b, and a two-stage deployment mechanism 116. In one or more embodiments, the first seal 114a and the second seal 114b may be unidirectional sealing elements, for example first and second packers, respectively. The packers may be cup packers. The unidirectional sealing elements 114a, 114b may be configured for sealing in a single direction. The centralizer 112 may be positioned along the tool string 110 between the first seal 114a and the second seal 114b. The two-stage6SLB-PrivateIS24.0123A-WO-PCTdeployment mechanism 116 may be located adjacent to the second seal 114b along the tool string 110 within the horizontal section 118.

[0028] The centralizer 112 may be configured to position the tool string 110 within the wellbore 102, and the first seal 114a and the second seal 114b may be configured to create seals between the tool string 110 and a surrounding formation or casing. The two-stage deployment mechanism 116 may be configured to deploy the centralizer 112 independently before deploying the first seal 114a or the second seal 114b. As shown in FIG. 1, the arrangement of the centralizer 112, the first seal 114a, the second seal 114b, and the two-stage deployment mechanism 116 along the tool string 110 may enable staged deployment operations within the horizontal section 118 of the wellbore 102.

[0029] Referring to FIG. 2A, a downhole packer including a two-stage deployment system 216 is shown in an initial configuration. The two-stage deployment system 216 may be configured to deploy a downhole centralizer and a downhole seal in a staged manner.The two-stage deployment system 216 may include a base pipe 220, a centralizer 212, a centralizer piston 222, and a seal piston 224.

[0030] The base pipe 220 may extend longitudinally and may provide structural support for the other components of the two-stage deployment system 216. The base pipe 220 may define a base pipe passageway through which fluids may flow during operations.The base pipe passageway may provide a flow path for pressurized fluid that may be used to activate the centralizer piston 222 and the seal piston 224.

[0031] With continued reference to FIG. 2 A, the centralizer 212 may be positioned along the base pipe 220. In the initial configuration shown in FIG. 2A, the centralizer 212 may be in an undeployed state. The centralizer 212 may be configured to extend outward from the base pipe 220 upon actuation to position a downhole tool within a wellbore. The centralizer piston 222 may be disposed about the base pipe 220. The centralizer piston 222 may be configured to actuate the centralizer 212. The centralizer piston 222 may be coupled to the centralizer 212 such that movement of the centralizer piston 222 may cause the centralizer 212 to deploy. As shown in FIG. 2A, the centralizer piston 222 may be positioned within the two-stage deployment system 216 in a manner that enables the7SLB-PrivateIS24.0123A-WO-PCTcentralizer piston 222 to move axially along the base pipe 220 during deployment operations.

[0032] The seal piston 224 may be disposed about the base pipe 220 and may be positioned adjacent to the centralizer piston 222 along the base pipe 220. The seal piston 224 may be coupled to a downhole seal 214. In the initial configuration shown in FIG. 2A, the seal piston 224 may be in an undeployed state. The seal piston 224 may be configured to actuate the downhole seal independently from the centralizer 212. The arrangement of the centralizer piston 222 and the seal piston 224 relative to the base pipe 220 may enable sequential deployment of the centralizer 212 and the downhole seal through coordinated operation of the centralizer piston 222 and the seal piston 224.

[0033] Referring to FIG. 2B, the two-stage deployment system 216 is shown in an intermediate configuration. In this intermediate configuration, the centralizer 212 may be in a deployed state, extending outward from the base pipe 220 at an angle. The centralizer 212 may extend away from the base pipe 220 to engage with a surrounding surface within a wellbore. The deployed state of the centralizer 212 may position a downhole tool within the wellbore prior to activation of a sealing mechanism, including the seal 214.

[0034] With continued reference to FIG. 2B, a seal 214 may be positioned along the base pipe 220. The seal 214 may be located below the centralizer 212 along the base pipe 220. In the intermediate configuration shown in FIG. 2B, the seal 214 may remain in an undeployed state. The seal 214 may be configured to provide a sealing function when activated. The two-stage deployment system 216 may be configured to deploy the centralizer 212 prior to deploying the seal 214.

[0035] As shown in FIG. 2B, the centralizer piston 222 may be disposed at a deployed centralizer position relative to the base pipe 220. The centralizer piston 222 may have moved axially along the base pipe 220 from an initial position to the deployed centralizer position, thereby causing the centralizer 212 to extend outward from the base pipe 220.The movement of the centralizer piston 222 to the deployed centralizer position may correspond to deployment of the centralizer 212.

[0036] In the intermediate configuration depicted in FIG. 2B, the seal piston 224 may be disposed at a first position relative to the centralizer piston 222. The seal piston 224 may8SLB-PrivateIS24.0123A-WO-PCTremain at the first position while the centralizer piston 222 has moved to the deployed centralizer position. Because the seal piston 224 remains at the first position relative to the centralizer piston 222, the seal 214 may remain undeployed in this intermediate configuration. The arrangement of the centralizer piston 222 at the deployed centralizer position and the seal piston 224 at the first position may correspond to a second configuration of the two-stage deployment system 216 in which a centralizer activation port is open and a seal activation port is occluded. This staged arrangement may enable the centralizer 212 to deploy before the seal 214 is activated.

[0037] Referring to FIG. 2C, the two-stage deployment system 216 of the downhole packer is shown in a deployed configuration. Tn this deployed configuration, both the centralizer 212 and the seal 214 may be in extended positions, projecting outward from the base pipe 220. The centralizer 212 may engage with a surrounding surface within a wellbore to position a downhole tool, and the seal 214 may provide a sealing function between the downhole tool and the surrounding formation or casing.

[0038] With continued reference to FIG. 2C, the two-stage deployment system 216 may be disposed in a third configuration. In the third configuration, a seal activation port may be open. The open state of the seal activation port may allow pressurized fluid to communicate with the seal piston 224, thereby enabling activation of the seal 214. The seal activation port may transition from an occluded state to an open state after the centralizer 212 has been deployed.

[0039] As shown in FIG. 2C, the centralizer piston 222 may be disposed at the deployed centralizer position relative to the base pipe 220. The centralizer piston 222 may remain at the deployed centralizer position in the third configuration, maintaining the centralizer 212 in the extended position. The centralizer piston 222 may have completed axial travel along the base pipe 220 corresponding to full deployment of the centralizer 212. In one or more embodiments, the centralizer 212 may be configured to deploy in any size wellbore diameter for which the centralizer 212 may be designed, before the seal 214 is deployed. In one or more embodiments, the deployment of the centralizer 212 depends on a force activating the piston 22 and a force of the seal 214 against a surface of the wellbore in which it is deployed.9SLB-PrivateIS24.0123A-WO-PCT

[0040] Tn the third configuration depicted in FIG. 2C, the seal piston 224 may be disposed at a second position relative to the centralizer piston 222. The second position of the seal piston 224 may be different from the first position described with reference to FIG.2B. Movement of the seal piston 224 from the first position to the second position relative to the centralizer piston 222 may cause the seal 214 to deploy. The seal piston 224 may move to the second position in response to pressurized fluid entering through the open seal activation port.

[0041] The deployed configuration shown in FIG. 2C may represent a state in which both centralizing and sealing functions are active. The centralizer 212 may position the downhole tool within the wellbore while the seal 214 may create a seal between the downhole tool and the surrounding formation or casing. The arrangement of the centralizer piston 222 at the deployed centralizer position and the seal piston 224 at the second position may correspond to completion of the staged deployment sequence enabled by the two-stage deployment system 216.

[0042] Referring to FIG. 3, a base pipe 320 is shown in an isometric view illustrating the arrangement of activation ports. The base pipe 320 may be a cylindrical tubular component that includes a centralizer activation port 326 and a seal activation port 328.The centralizer activation port 326 may be positioned on an outer surface of the base pipe 320 and may be configured to allow fluid communication for activating a centralizing mechanism. The seal activation port 328 may be located in a different position on the base pipe 320, offset from the centralizer activation port 326.

[0043] With continued reference to FIG. 3, the centralizer activation port 326 and the seal activation port 328 may be positioned in different planes on the base pipe 320. The centralizer activation port 326 may be defined in a first plane passing through a central longitudinal axis of the base pipe 320. The seal activation port 328 may be defined in a second plane passing through the central longitudinal axis of the base pipe 320, the second plane being different from the first plane. The centralizer activation port 326 and the seal activation port 328 may be offset radially about a circumference of the base pipe 320. This offset arrangement of the activation ports may enable staged deployment of the centralizing and sealing mechanisms.10SLB-PrivateIS24.0123A-WO-PCT

[0044] Referring to FIG. 4, a cross-sectional view of a two-stage deployment system of a downhole packer assembly is shown. The cross-sectional viewing plane of FIG. 4 may pass through the centralizer activation port 326 shown in FIG. 3. A base pipe 420 may form a central structural element of the assembly. The base pipe 420 may define a central passageway 432 extending through an interior of the base pipe 420. The central passageway 432 may provide a flow path for fluids through the system.

[0045] A centralizer piston 422 may be disposed about the base pipe 420. The centralizer piston 422 may be configured to move axially along the base pipe 420 during deployment operations. The base pipe 420 may define a first centralizer activation port 426a and a second centralizer activation port 426b . Any number of activation ports may be included in the two-stage deployment system, which may be positioned at various positions about the base pipe 420. The centralizer activation ports 426a and 426b may provide fluid communication between the central passageway 432 and a volume 430 defined between the centralizer piston 422 and the base pipe 420.

[0046] As shown in FIG. 4, the volume 430 may be defined between the centralizer piston 422 and the base pipe 420. The volume 430 may provide a chamber for receiving pressurized fluid. An initializer 428 may be positioned within the assembly. The initializer 428 may be coupled to, or otherwise selectively actuated by, a motor or other actuator mechanism. The actuator coupled to the initializer 428 may be electrically coupled to the controller 106, which may be configured to selectively operate the actuator and thus the initializer 428. When the initializer 428 is moved by the actuator mechanism, the centralizer activation ports 426a and 426b may be uncovered. In an uncovered state, the centralizer activation ports 426a and 426b may be open and unobstructed.

[0047] With continued reference to FIG. 4, when the centralizer activation ports 426a and 426b are uncovered, fluid and pressure from the central passageway 432 may enter the volume 430 through the centralizer activation ports 426a and 426b. The fluid may build up in the volume 430 and may push the centralizer piston 422 to move relative to the base pipe 420. The arrangement of the centralizer activation ports 426a and 426b relative to the centralizer piston 422 and the volume 430 may enable controlled sequential activation of the centralizing mechanism before the sealing mechanism.11SLB-PrivateIS24.0123A-WO-PCT

[0048] Referring to FIG. 5, a two-stage deployment system 516 is shown in a cross-sectional view. The two-stage deployment system 516 may include a centralizer 512 positioned along a base pipe 520. The base pipe 520 may extend through a center of the assembly and may include a base pipe passageway 532 that provides fluid communication through the system. The base pipe passageway 532 may extend through an interior of the base pipe 520 and may provide a flow path for pressurized fluid used to activate deployment mechanisms.

[0049] With continued reference to FIG. 5, a centralizer piston 522 may be disposed about the base pipe 520. The centralizer piston 522 may be configured to actuate the centralizer 512. A seal piston 524 may also be positioned about the base pipe 520 adjacent to the centralizer piston 522. The seal piston 524 may be coupled to a downhole seal and may be configured to actuate the sealing mechanism independently from the centralizer piston 522.

[0050] As shown in FIG. 5, the base pipe 520 may define a centralizer activation port 526, which may be drilled or otherwise formed through a wall thickness of the base pipe 520, that provides fluid communication between the base pipe passageway 532 and a volume 530 located between the base pipe 520 and the centralizer piston 522. The centralizer activation port 526 may function as a first port through which pressure from the base pipe passageway 532 may activate the centralizer piston 522. An initializer 528 may be positioned within the base pipe passageway 532 near the centralizer activation port 526.The initializer 528 may be configured to initiate the deployment sequence by uncovering the centralizer activation port 526.

[0051] The base pipe 520 may define a second port (not shown in FIG. 5 but illustrated in FIGS. 7A and 7B and described in further detail below) that provides fluid communication between the base pipe passageway 532 and a volume between the base pipe 520 and the seal piston 524. The second port may provide fluid communication to the seal piston 524, which may activate the sealing mechanism independently from the centralizer piston 522. The arrangement of the first port and the second port may enable staged deployment where the centralizer 512 deploys before activation of the sealing mechanism.12SLB-PrivateIS24.0123A-WO-PCT

[0052] A shear mechanism 534 may connect the centralizer piston 522 to the seal piston 524. The shear mechanism 534 may include a shear screw having a shear force limit.The shear mechanism 534 may hold the centralizer piston 522 to the seal piston 524 while both pistons move relative to the base pipe 520. The shear mechanism 534 may allow the centralizer piston 522 to drive the centralizer 512 during initial deployment until sufficient force causes the shear mechanism 534 to release.

[0053] A stop 536 may be positioned to limit the travel of the centralizer piston 522.The stop 536 may function as a stop mechanism configured to prevent the centralizer piston 522 from traveling beyond a predetermined distance relative to the base pipe 520. The centralizer piston 522 may be configured to contact the stop 536 upon deployment of the centralizer 512. When the centralizer piston 522 contacts the stop 536, the force reaction in the shear mechanism 534 may become high enough to cause the shear mechanism 534 to fail in shear. In a second configuration of the two-stage deployment system 516, the stop 536 may prevent the centralizer piston 522 from travelling beyond the predetermined distance relative to the base pipe 520.

[0054] With continued reference to FIG. 5, a ratchet 538 may be disposed along the centralizer 512. The ratchet 538 may function as a ratchet mechanism configured to prevent the seal piston 524 from moving after the downhole seal is deployed. The ratchet 538 may maintain the deployed position of the seal piston 524, and thus the downhole seal, after actuation and deployment. In a third configuration of the two-stage deployment system 516, the ratchet 538 may prevent the seal piston 524 from moving back after the downhole seal is deployed, thereby maintaining the sealing function.

[0055] Referring to FIG. 6A, a cross-sectional view of a two-stage deployment system in an initial configuration is shown. The two-stage deployment system may include a base pipe 620, a centralizer piston 622, a seal piston 624, a centralizer activation port 626, a volume 630, a first shear mechanism 634a, a second shear mechanism 634b, and a stop 636. The base pipe 620 may extend longitudinally and may provide structural support for the other components of the two-stage deployment system.

[0056] With continued reference to FIG. 6A, the centralizer piston 622 may be disposed about the base pipe 620. The centralizer piston 622 may be coupled to the base13SLB-PrivateIS24.0123A-WO-PCTpipe 620 via the first shear mechanism 634a. The first shear mechanism 634a may have a first shear limit. The first shear mechanism 634a may include a first shear screw coupling the centralizer piston 622 to the base pipe 620. The centralizer piston 622 may be secured to a centralizer sub-assembly, which may ensure that a centralizer begins to deploy when the centralizer activation port 626 is uncovered.

[0057] As shown in FIG. 6A, the seal piston 624 may be disposed about the base pipe 620 adjacent to the centralizer piston 622. The seal piston 624 may be coupled to the centralizer piston 622 via the second shear mechanism 634b. The second shear mechanism 634b may have a second shear limit greater than the first shear limit of the shear mechanism 634a. The second shear mechanism 634b may include a second shear screw coupling the seal piston 624 to the centralizer piston 622. The configuration of the first shear mechanism 634a having the first shear limit and the second shear mechanism 634b having the second shear limit greater than the first shear limit may enable staged deployment of the centralizing and sealing mechanisms.

[0058] With continued reference to FIG. 6A, the centralizer activation port 626 may be formed in the base pipe 620. The centralizer activation port 626 may provide fluid communication between a base pipe passageway and the volume 630. The volume 630 may be defined between the base pipe 620 and the centralizer piston 622. The volume 630 may receive pressurized fluid through the centralizer activation port 626 during deployment operations. The stop 636 may be positioned to limit the travel of the centralizer piston 622 and may define an endpoint for piston movement.

[0059] Referring to FIG. 6B, the two-stage deployment system is shown in a configuration where the first shear mechanism 634a has failed. In a first stage of deployment, pressure from fluid entering the volume 630 through the centralizer activation port 626 may press on the centralizer piston 622. The pressure may build in the volume 630 until the pressure overcomes the first shear limit of the first shear mechanism 634a.When the pressure overcomes the first shear limit, the first shear mechanism 634a may fail as shown in FIG. 6B.

[0060] With continued reference to FIG. 6B, after the shear mechanism 634a fails, the centralizer piston 622 and the seal piston 624 may move relative to the base pipe 620. The14SLB-PrivateIS24.0123A-WO-PCTcentralizer piston 622 and the seal piston 624 may move together until the centralizer piston 622 contacts the stop 636. The centralizer piston 622 may be configured to contact the stop 636 upon deployment of a centralizer coupled to the centralizer piston 622. The second shear mechanism 634b may hold the seal piston 624 to the centralizer piston 622 while the two pistons move together relative to the base pipe 620 after the first shear mechanism 634a fails. Because the second shear mechanism 634b has the second shear limit greater than the first shear limit of the first shear mechanism 634a, the second shear mechanism 634b may remain intact while the centralizer piston 622 and the seal piston 624 move together during the first stage of deployment.

[0061] Referring to FIG. 7A, a cross-sectional view of the two-stage deployment system is shown with the cross-sectional plane passing through a seal activation port 739.The cross-sectional view of FIG. 7A may depict a same or similar assembly shown in FIGS.6A and 6B but viewed from a different cross-sectional plane. The two-stage deployment system may include a base pipe 720, a centralizer piston 722, a seal piston 724, a base pipe passageway 732, a first shear mechanism 734a, a second shear mechanism 734b, the seal activation port 739, and an intermediate passageway 740.

[0062] The base pipe 720 may extend longitudinally and may provide structural support for the other components of the two-stage deployment system. The base pipe 720 may define the base pipe passageway 732 extending through an interior of the base pipe 720. The base pipe passageway 732 may provide a flow path for pressurized fluid used to activate deployment mechanisms. The centralizer piston 722 may be disposed about the base pipe 720 and may be configured to actuate a centralizer to which the centralizer piston 722 is coupled. The seal piston 724 may be disposed about the base pipe 720 adjacent to the centralizer piston 722 and may be configured to actuate a seal of the downhole packer tool.

[0063] As shown in FIG. 7A, the base pipe 720 may define a seal activation port 739.The seal activation port 739 may be configured such that pressure from the base pipe passageway 732 passes therethrough to the volume 730 between the base pipe 720 and the seal piston 724 to activate the seal piston 724. The seal activation port 739 may be configured such that the pressure activates the seal piston 724 separately from the15SLB-PrivateIS24.0123A-WO-PCTactivation of the centralizer piston 722. The seal activation port 739 may provide fluid communication between the base pipe passageway 732 and a volume between the base pipe 720 and the seal piston 724. The intermediate passageway 740 may extend through the assembly and may be in fluid communication with the base pipe passageway 732.

[0064] With continued reference to FIG. 7A, the first shear mechanism 734a and the second shear mechanism 734b may be positioned at different locations along the assembly.The first shear mechanism 734a may couple the centralizer piston 722 to the base pipe 720 and may have a first shear limit. The second shear mechanism 734b may couple the seal piston 724 to the centralizer piston 722 and may have a second shear limit greater than the first shear limit. The first shear mechanism 734a may include a first shear screw, and the second shear mechanism 734b may include a second shear screw. The first shear screw may be configured to shear upon deployment of the centralizer, thereby allowing the centralizer piston 722 to move relative to the base pipe 720.

[0065] As further shown in FIG. 7A, the centralizer activation port may be configured to directly set the centralizer mechanism when uncovered and the centralizer piston 722 is activated, causing the centralizer to begin deployment. The first port may be configured to be uncovered before the second port during an operation of the two-stage deployment system. The second port, corresponding to the seal activation port 739, may be configured to be uncovered after the centralizer has been deployed. In the configuration shown in FIG.7A, the seal activation port 739 may be occluded by the seal piston 724.

[0066] Referring to FIG. 7B, the two-stage deployment system is shown in a configuration where the centralizer piston 722 and the seal piston 724 have moved to a point where the seal activation port 739 is open (i.e., uncovered or otherwise unobstructed by the centralizer piston 722). In this configuration, the seal activation port 739 may be unobstructed to allow fluid pressure from the intermediate passageway 740 to enter a volume 730 between the base pipe 720 and the seal piston 724. The intermediate passageway 740 may be in fluid communication with the base pipe passageway 732, thereby providing pressurized fluid to the seal activation port 739.

[0067] With continued reference to FIG. 7B, fluid pressure from the intermediate passageway 740 may build up in the volume until the pressure overcomes the second shear16SLB-PrivateIS24.0123A-WO-PCTlimit of the second shear mechanism 734b. The second shear mechanism 734b may be configured such that the force reaction in the second shear mechanism 734b becomes high enough to shear only once the centralizer has deployed. The second shear screw of the second shear mechanism 734b may be configured to shear after the first shear screw has sheared during an operation of the two-stage deployment system. The second shear screw may be configured to shear after the first shear screw has sheared and the seal activation port 739 has been uncovered.

[0068] As shown in FIG. 7B, when the shear mechanism 734b fails, the seal piston 724 may be free to move relative to the centralizer piston 722 and the base pipe 720.Movement of the seal piston 724 relative to the centralizer piston 722 may deploy the seal to which the seal piston 724 is coupled. In this way, as shown in FIGS. 6A, 6B, 7A, and 7B, the shear mechanisms 734a and 734b may fail at different times so that the seal cannot deploy until the centralizer is deployed.

[0069] The two-stage deployment system may include a first configuration in which the centralizer activation port and the seal activation port 739 are occluded, the centralizer piston 722 is disposed at an un-deployed centralizer position relative to the base pipe 720, and the seal piston 724 is disposed at a first position relative to the centralizer piston 722.This first configuration may correspond to the configuration shown in FIG. 6A and may correspond to the initial configuration of the two-stage deployment system 216 shown in FIG. 2A. In this way, the three configurations of the assembly shown in FIGS. 2A, 2B, and 2C may be achieved through the staged deployment sequence enabled by the arrangement of the shear mechanisms 734a and 734b and the activation ports 626 and 739.

[0070] The two-stage deployment system described herein may address challenges associated with deploying complex sealing configurations in open hole packer applications. By providing separate activation ports for the centralizer and the seal, the system may enable independent control over the deployment sequence of these mechanisms. The arrangement of the centralizer activation port and the seal activation port in different planes on the base pipe may allow the centralizer to be fully deployed before the seal activation port is uncovered. This staged approach may accommodate seal designs17SLB-PrivateIS24.0123A-WO-PCTthat benefit from proper centralization of the downhole tool prior to engagement of the sealing elements with the wellbore wall.

[0071] The shear mechanisms described with reference to FIGS. 6A, 6B, 7A, and 7B may provide a mechanical means for controlling the deployment sequence. The first shear mechanism having a first shear limit and the second shear mechanism having a second shear limit greater than the first shear limit may ensure that the centralizer piston moves before the seal piston is released. The stop mechanism may define an endpoint for centralizer piston travel, and the contact between the centralizer piston and the stop may generate sufficient force to shear the second shear mechanism only after the centralizer has completed deployment. In some aspects, this arrangement may prevent premature activation of the sealing mechanism while the centralizer is still deploying.

[0072] The volume defined between the base pipe and the pistons, in combination with the activation ports, may provide a pressure-driven actuation system for the two-stage deployment mechanism. Pressurized fluid from the base pipe passageway may enter the volume through the centralizer activation port to drive the centralizer piston, and subsequently may enter through the seal activation port to drive the seal piston after the centralizer has deployed. The ratchet mechanism may maintain the deployed position of the seal after actuation, which may help preserve the sealing function during downhole operations. In some embodiments, this configuration may be suitable for large expansion open hole packer applications where the centralizing function is performed before the sealing elements are expanded against the formation.

[0073] The embodiments of downhole tools have been primarily described with reference to wellbore drilling operations; the downhole tools described herein may be used in applications other than the drilling of a wellbore. In other embodiments, downhole tools according to the present disclosure may be used outside a wellbore or other downhole environment used for the exploration or production of natural resources. For instance, downhole tools of the present disclosure may be used in a borehole used for placement of utility lines. Accordingly, the terms “wellbore,” “borehole” and the like should not be interpreted to limit tools, systems, assemblies, or methods of the present disclosure to any particular industry, field, or environment.18SLB-PrivateIS24.0123A-WO-PCT

[0074] One or more specific embodiments of the present disclosure are described herein. These described embodiments are examples of the presently disclosed techniques.Additionally, in an effort to provide a concise description of these embodiments, not all features of an actual embodiment may be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous embodiment-specific decisions will be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one embodiment to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0075] Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. For example, any element described in relation to an embodiment herein may be combinable with any element of any other embodiment described herein. Numbers, percentages, ratios, or other values stated herein are intended to include that value, and also other values that are “about” or “approximately” the stated value, as would be appreciated by one of ordinary skill in the art encompassed by embodiments of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least the variation to be expected in a suitable manufacturing or production process, and may include values that are within 5%, within 1%, within 0.1%, or within 0.01% of a stated value.

[0076] A person having ordinary skill in the art should realize in view of the present disclosure that equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made to embodiments disclosed herein without departing from the spirit and scope of the present disclosure. Equivalent constructions, including functional “means-plus-function” clauses are intended to cover the structures described herein as performing the recited function, including both structural equivalents that operate in the same manner, and equivalent19SLB-PrivateIS24.0123A-WO-PCTstructures that provide the same function. It is the express intention of the applicant not to invoke means-plus-function or other functional claiming for any claim except for those in which the words ‘means for’ appear together with an associated function. Each addition, deletion, and modification to the embodiments that falls within the meaning and scope of the claims is to be embraced by the claims.

[0077] The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments are to be considered as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. Changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.20SLB-Private

Claims

IS24.0123A-WO-PCTCLAIMS1. A downhole tool, comprising:a base pipe defining a base pipe passageway;a centralizer coupled to the base pipe;a seal coupled to the base pipe; anda two-stage deployment system configured to deploy the centralizer and the seal, the two-stage deployment system comprising:a centralizer piston disposed about the base pipe and coupled to the base pipe via a first shear mechanism having a first shear limit; anda seal piston coupled to the centralizer piston via a second shear mechanism having a second shear limit greater than the first shear limit;wherein the base pipe defines:a first port through which pressure from the base pipe passageway is configured to activate the centralizer piston; anda second port through which the pressure is configured to activate the seal piston separately from the centralizer piston.

2. The downhole tool of claim 1, wherein:the first port provides fluid communication between the base pipe passageway and a volume between the base pipe and the centralizer piston; andthe second port provides fluid communication between the base pipe passageway and the volume between the base pipe and the seal piston.21SLB-PrivateIS24.0123A-WO-PCT3. The downhole tool of claim 1, further comprising a stop mechanism configured to prevent the centralizer piston from travelling beyond a predetermined distance relative to the base pipe.

4. The downhole tool of claim 3, wherein the centralizer piston is configured to contact the stop mechanism upon deployment of the centralizer.

5. The downhole tool of claim 1, further comprising a ratchet mechanism configured to prevent the seal piston from moving after the seal is deployed.

6. The downhole tool of claim 1, wherein the two-stage deployment system is configured to deploy the centralizer prior to deploying the seal.

7. The downhole tool of claim 6, wherein the second port is configured to be uncovered after the centralizer has been deployed.

8. The downhole tool of claim 1, wherein the first port is defined in a first plane passing through a central axis of the base pipe and the second port is defined in a second plane passing through the central axis, the second plane different than the first plane.

9. The downhole tool of claim 8, wherein the first port is configured to be uncovered before the second port during an operation of the two-stage deployment system.22SLB-PrivateIS24.0123A-WO-PCT10. The downhole tool of claim 1, wherein the first shear mechanism comprises a first shear screw coupling the centralizer piston to the base pipe.

11. The downhole tool of claim 10, wherein:the second shear mechanism comprises a second shear screw coupling the seal piston to the centralizer piston; andthe second shear screw is configured to shear after the first shear screw has sheared during an operation of the two-stage deployment system.

12. A downhole tool string, comprising:a base pipe defining a base pipe passageway;a centralizer;a seal;a centralizer piston surrounding the base pipe and coupled to the centralizer, the centralizer piston coupled to the base pipe via a first shear screw, wherein the base pipe defines a centralizer activation port fluidly coupling the base pipe passageway to a volume between the base pipe and the centralizer piston; anda seal piston coupled to the seal, the seal piston coupled to the centralizer piston via a second shear screw, wherein the base pipe defines a seal activation port fluidly coupling the base pipe passageway to the volume between the base pipe and the seal piston.

13. The downhole tool string of claim 12, wherein the centralizer activation port and the seal activation port are offset radially about a circumference of the base pipe.23SLB-PrivateIS24.0123A-WO-PCT14. The downhole tool string of claim 12, wherein the first shear screw has a first shear limit and the second shear screw has a second shear limit greater than the first shear limit.

15. The downhole tool string of claim 14, wherein the first shear screw is configured to shear upon deployment of the centralizer, thereby allowing the centralizer piston to move relative to the base pipe.

16. The downhole tool string of claim 15, wherein the second shear screw is configured to shear after the first shear screw has sheared and the seal activation port has been uncovered.24SLB-PrivateIS24.0123A-WO-PCT17. A two-stage deployment mechanism for a downhole centralizer and a downhole seal, the two-stage deployment mechanism comprising:a base pipe defining a base pipe passageway;a centralizer activation port;a seal activation port;a centralizer piston disposed about the base pipe and coupled to the downhole centralizer; anda seal piston disposed about the base pipe and coupled to the downhole seal; wherein the two-stage deployment mechanism comprises:a first configuration in which the centralizer activation port and the seal activation port are occluded, the centralizer piston is disposed at an un-deployed centralizer position relative to the base pipe, and the seal piston is disposed at a first position relative to the centralizer piston;a second configuration in which the centralizer activation port is open and the seal activation port is occluded, the centralizer piston is disposed at a deployed centralizer position relative to the base pipe, and the seal piston is disposed at the first position relative to the centralizer piston; anda third configuration in which the seal activation port is open, the centralizer piston is disposed at the deployed centralizer position relative to the base pipe, and the seal piston is disposed at a second position relative to the centralizer piston.25SLB-PrivateIS24.0123A-WO-PCT18. The two-stage deployment mechanism of claim 17, further comprising a stop mechanism configured to prevent the centralizer piston from travelling beyond a predetermined distance relative to the base pipe in the second configuration.

19. The two-stage deployment mechanism of claim 18, wherein the centralizer piston is configured to contact the stop mechanism upon deployment of the downhole centralizer.

20. The two-stage deployment mechanism of claim 17, further comprising a ratchet mechanism configured to prevent the seal piston from moving after the downhole seal is deployed in the third configuration.26SLB-Private

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