Hydraulic set liner hanger packer

Abstract

A method and apparatus for a downhole tool is disclosed. In one embodiment, the downhole tool includes a liner hanger assembly for anchoring a liner in a wellbore, a packer assembly for effecting an annular barrier between liner and casing strings and a polished bore receptacle assembly to receive tieback casing strings to the surface. The downhole tool includes a stationary piston, a moving piston and one or more ports disposed axially below the stationary piston and axially above the moving piston configured to form a hydraulic cylinder when coupled to the polished bore receptacle. Increasing tubing pressure actuates the moving piston axially to set the liner hanger assembly without setting the packer assembly.

Description

Hydraulic Set Liner Hanger PackerCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 524,094 filed June 29, 2023, the entire contents of which are incorporated herein by reference thereto.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.BACKGROUND OF THE INVENTIONField of the Invention

[0003] The field of the invention is liner systems used to suspend a liner concentrically within a wellbore and provide a barrier between liner and casing strings.Background of the Invention

[0004] A well borehole is generally drilled in successively smaller diameter sections from the surface to a selected depth. Rather than suspending a plurality of successive concentric casings from the surface, a liner may be suspended adjacent to the bottom end of the previously suspended casing or from a previously suspended liner to the bottom of the next drilled section. A liner may be a casing that is not run to the surface. A liner hanger may be used to suspend the liner within the previously suspended casing or liner by radially expanding slips to contact the wall of the casing and transfer the liner load to the casing. Typically, a liner hanger has the capability to accept a tie back tool connecting the liner with a casing string to the surface if desired.

[0005] Hydraulically set liner hangers typically contain a hydraulic setting mechanism comprising either a moving hydraulic cylinder or a moving piston within a stationary hydraulic cylinder and may not need string manipulation to activate the anchoring slips. After reaching the selected setting depth, a ball or object is dropped from the surface, landing on a seat that is placed below the hydraulic setting mechanism of the liner hanger and that may be designed to accept the ball or object, effecting a seal to isolate tubing fluid from the liner string fluid and wellbore fluid.Increasing applied tubing pressure to a specified level may break a shear device allowing the hydraulic setting mechanism to activate the liner hanger anchoring slips and suspend the liner.

[0006] Conventionally, the hydraulic cylinder is located axially below the hanger slips and below the packer assembly. This location may expose the hydraulic cylinder to a pressure differential between internal tubing pressure and the annular pressure between liner string and casing string.

[0007] High pressure oil and gas reservoirs may present limitations to conventional hydraulic set liner hangers. Whereas the mandrel of the liner hanger may be made with a smaller internal diameter to account for increasing pressure differentials, the hydraulic cylinder is constrained by standardized annular dimensions formed by the internal diameter of the casing string and outer diameter of the liner string, and therefore may be generally less resistant to yielding from internal pressure or collapsing from external pressure.

[0008] The disadvantages of a hydraulic cylinder resident to the liner hanger may be overcome by the presently disclosed and claimed downhole tool, and a hydraulically actuated liner hanger is hereafter disclosed which may remove the hydraulic cylinder from the liner hanger assembly by using a polished bore receptacle to form a hydraulic cylinder chamber. After installation, the hydraulic cylinder chamber may be at hydrostatic pressure and may not be subject to pressure differential limitations of a conventional set hydraulic liner hanger.BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS

[0009] These and other needs in the art are addressed in one embodiment by a liner hanger that includes a stationary piston and a moving piston that are assembled concentrically about a mandrel and within a polished bore receptacle to form a hydraulic cylinder. When pressurized with tubing fluid, the moving piston breaks a shear device and strokes axially downward to actuate the slip assembly without actuating the packer assembly.

[0010] These and other needs in the art are addressed in another embodiment by a downhole tool. The downhole tool includes a mandrel configured to be releasably connected to a running string from above and coupled to a liner string from below. The mandrel contains one or more ports extending radially through a wall of the mandrel. The downhole tool also includes a first piston disposed concentrically around the mandrel and axially above the one or more ports. In addition, the downhole tool includes a second piston disposed concentrically around the mandreland axially below the one or more ports. The downhole tool also has a polished bore receptacle assembly disposed concentrically around the first and the second piston. Further, the downhole tool has a packer assembly disposed concentrically around the mandrel and axially below the second piston. Moreover, the downhole tool has a liner hanger assembly disposed concentrically around the mandrel and axially below the packer assembly. The first piston is coupled to the mandrel such that it is stationary. The polished bore receptacle assembly is received radially around the first and the second piston to form a hydraulic cylinder chamber. The first piston comprises one or more seals configured to prevent pressure communication between the hydraulic cylinder chamber and tubing fluid pressure. The second piston comprises one or more seals configured to prevent pressure communication between the hydraulic cylinder chamber and the annular space disposed axially below the piston between the mandrel and polished bore receptacle assembly, which is exposed to annular fluid and pressure between the downhole tool and casing string. The second piston is configured to move independently of the polished bore receptacle assembly. The second piston is configured to move axially downward in the annular space between the mandrel and the polished bore receptacle assembly when exposed to tubing pressure. The second piston is coupled with the packer assembly such that they are axially co-moving. The packer assembly comprises an element assembly with one or more ratchet rings, configured such that axial movement is constrained to a downward axial direction. The liner hanger assembly is coupled with the packer assembly such that they are axially co-moving. The liner hanger assembly comprises a hanger slip assembly with a ratchet ring, configured such that axial movement is constrained to a downward axial direction. The mandrel contains an internal profile or thread disposed axially below the liner hanger assembly to be releasably connected to a running string above to surface.

[0011] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:

[0013] Figures 1-2 illustrate sequentially lower portions of an embodiment disclosed herein of an assembled liner hanger packer with polished bore receptacle assembly, mandrel, hydraulic cylinder assembly, packer assembly, and liner hanger assembly in a run-in configuration;

[0014] Figure 3 illustrates a detailed cross-sectional view of the hydraulic cylinder assembly in a run-in configuration as shown in Figure 2;

[0015] Figure 4 illustrates a detailed cross-sectional view of the packer assembly shown in a run- in configuration as shown in Figure 2;

[0016] Figure 5 illustrates a detailed cross-sectional view of the liner hanger assembly in the run- in configuration as shown in Figure 2.

[0017] Figure 6 illustrates an embodiment of activation of the liner hanger assembly within a casing string; and

[0018] Figure 7 illustrates an embodiment of activation of the packer assembly within a casing string.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In an embodiment as shown in the Figures, downhole tool 90 includes liner hanger packer 100 and mandrel 106 adapted to be releasably connected to additional components of a running string above to surface (not shown) and coupled to additional components of a liner string below (not shown), with mandrel 106 containing one or more ports 170 extending radially through wall 200 of mandrel 106. Downhole tool 90 also includes first piston 108 (stationary piston 108) disposed concentrically around mandrel 106 and axially above port 170. In addition, downhole tool 90 includes second piston 116 (moving piston 116) disposed concentrically around mandrel 106 and axially below port 170. Downhole tool 90 may further include polished bore receptacle 102, disposed concentrically around first piston 108 and second piston 116. Additionally, downhole tool 90 may include packer assembly 122, disposed concentrically around mandrel 106 and axially below second piston 116. Further, downhole tool 90 may include liner hanger assembly 152 disposed concentrically around mandrel 106 and axially below packer assembly 122.

[0020] In embodiments as shown in the Figures, first piston 108 is coupled to mandrel 106 such that it is stationary. Polished bore receptacle 102 is received radially around first piston 108 and second piston 116 to form hydraulic cylinder chamber 172. First piston 108 comprises one or more seals 112, 114 configured to prevent pressure communication between hydraulic cylinder chamber 172 and annular space 174 disposed axially above piston 108 between mandrel 106 and polished bore receptacle 102. Second piston 116 comprises one or more seals 118, 120 configured to prevent pressure communication between hydraulic cylinder chamber 172 and annular space 174 axially below piston 116 between mandrel 106 and polished bore receptacle 102. In addition, second piston 116 is configured to move independently of polished bore receptacle 102. Additionally, second piston 116 is configured to move axially downward in annular space 174 between mandrel 106 and polished bore receptacle 102 when exposed to tubing pressure. Moreover, second piston 116 is coupled with packer assembly 122 such that they are axially comoving.

[0021] In an embodiment as shown in the Figures, packer assembly 122 comprises packer cone 136, packer element 138, seal 140, hold down slips 142, slip cone 146 and one or more ratchet rings 134, configured such that axial movement of packer cone 136, packer element 138, seal 140, and hold down slips 142 is constrained to the downward axial direction with respect to rubber mandrel 124 and slip cone 146. Further, liner hanger assembly 152 is coupled with packer assembly 122 such that they are axially co-moving. In addition, liner hanger assembly 152 comprises ratchet ring 148, ratchet housing 150, bearing / spacer 154, hanger cone 156, and a plurality of hanger slips 158, configured such that axial movement of ratchet ring 148, ratchet housing 150, bearing / spacer 154, hanger cone 156, hanger slips 158 and packer assembly 122 is constrained to the downward axial direction with respect to the mandrel 106. Mandrel 106 contains an internal profile 164 or thread or adaptation axially below liner hanger assembly 152 to be releasably connected to additional components of a running string above to surface (not shown).

[0022] Figure 1 illustrates an embodiment of downhole tool 90 showing polished bore receptacle 102 in a run-in configuration.

[0023] Figure 2 illustrates an embodiment of downhole tool 90 in a run-in configuration having liner hanger packer 100. Liner hanger packer 100 has polished bore receptacle 102, hydraulic cylinder assembly 104, packer assembly 122, and mandrel 106. Mandrel 106 has wall 200.

[0024] Figure 3 illustrates an embodiment of hydraulic cylinder assembly 104 and polished bore receptacle 102 in a run-in configuration. As shown, hydraulic cylinder assembly 104 has stationary piston 108, locking wire 110, seal 112, seal 114, moving piston 116, seal 118, seal 120, and rubber mandrel 124. Mandrel 106 is also shown containing wall 200 and port 170. Locking wire 110 couples stationary piston 108 to mandrel 106, though a thread or other adaptation may be used in other embodiments. Polished bore receptacle 102, stationary piston 108, seal 112, seal 114, moving piston 116, seal 118, seal 120, and mandrel 106 with port 170 through wall 200 form a hydraulic cylinder chamber 172 in hydraulic communication with tubing fluid. Polished bore receptacle 102, moving piston 116, seal 118, seal 120 and mandrel 106 form a seal barrier to annular fluid entering hydraulic cylinder chamber 172.

[0025] Figure 4 illustrates an embodiment of packer assembly 122 in a run-in configuration. Mandrel 106 is also shown. As shown, packer assembly 122 shows locking wire 126, shear device 128, shear ring 130, ratchet ring 132, ratchet ring 134, packer cone 136, packer element 138, seal 140, hold down slips 142, seal 144, slip cone 146, ratchet ring 148, and ratchet housing 150. Rubber mandrel 124 is also shown. Locking wire 126 couples polished bore receptacle 102 to shear ring 130 though a thread or other adaptation may be used in other embodiments. Shear ring 130 contains ratchet ring 132 which allows axial movement in the downward direction only with respect to rubber mandrel 124. Shear ring 130 has shear device 128, which temporarily couples shear ring 130 to mandrel 106 until a prescribed compression force is placed on polished bore receptacle 102, shearing the shear device 128 and allowing axial movement of the polished bore receptacle 102, shear ring 130 and ratchet ring 132 in the downward direction. Rubber mandrel 124 has slots 178 in wall 180, which allow shear device 128 to pass through rubber mandrel 128 and temporarily couple with mandrel 106. Rubber mandrel 124 has seal 144 to form a fluid and pressure barrier between rubber mandrel 124 and mandrel 106. Packer cone 136 contains ratchet ring 134 allowing axial movement in the downward direction only with respect to rubber mandrel 124. Packer element 138 has seal 140 to form a fluid and pressure barrier between packer element 138 and rubber mandrel 124. Hold down slips 142 and slip cone 146 form an anchoring mechanism from upward direction upon activation.

[0026] Figure 5 illustrates an embodiment of liner hanger assembly 152. Liner hanger assembly 152 includes bearing / spacer 154, hanger cone 156, shear device 182, a plurality of hanger slips 158, slip retainer 184, locking wire 160, and bearing 162. Mandrel 106 and internal profile 164 arealso shown. Bearing / spacer 154 and bearing 162 allow rotation of downhole tool 90 with respect to hanger cone 156, plurality of hanger slips 158 and slip retainer 184. Hanger cone 156 and plurality of hanger slips 158 form an anchoring mechanism from downward movement of downhole tool 90 upon activation. Locking wire 160 constrains axial movement of slip retainer 184 in the upwards direction.

[0027] Figure 6 illustrates an embodiment of downhole tool 90 in a casing string showing activation of liner hanger assembly 152 with tubing fluid pressure. Upon exposure of hydraulic cylinder chamber 172 from port 170 in wall 200 of mandrel 106 to an increase in tubing fluid pressure relative to annular fluid pressure, there exists a differential pressure between tubing fluid and annular fluid. The differential pressure exerts a net downward force on moving piston 116 relative to polished bore receptacle 102 and mandrel 106. The net downward force on moving piston 116 is transferred through rubber mandrel 124, slip cone 146, ratchet housing 150, bearing / spacer 154, hanger cone 156, and shear device 182. The net downward force is resisted by the temporary coupling of shear device 182 to mandrel 106. Upon the downward force reaching the prescribed shear value of shear device 182, shear device 182 shears and the net downward force causes downward movement of moving piston 116, rubber mandrel 124, slip cone 146, ratchet housing 150, bearing / spacer 154, and hanger cone 156, actuating the plurality of hanger slips 158 radially outwards and into contact with casing string 166 to form an anchoring mechanism against downward movement of downhole tool 90 with respect to casing string 166. Downard forces on mandrel 106 are conveyed from mandrel 106 to ratchet thread 188 on mandrel 106 into ratchet ring 148, into ratchet housing 150, into bearing / spacer 154, into hanger cone 156, into plurality of hanger slips 158 and into casing string 166. During activation of liner hanger assembly 152, packer assembly 122 remains stationary in the moving reference frame of rubber mandrel 124 by ratchet thread 186 on rubber mandrel 124 constraining ratchet ring 134 to movement in the axially downward direction.

[0028] Figure 7 illustrates an embodiment of downhole tool 90 in a casing string showing activation of packer assembly 122. Placing a compressive force on polished bore receptacle 102 exerts a net downward force on polished bore receptacle 102 relative to mandrel 106. The net downward force on polished bore receptacle 102 is transferred through shear ring 130 and shear device 128. The net downward force is resisted by the temporary coupling of shear device 128 to mandrel 106. Upon the downward force reaching the prescribed shear value of shear device 128,shear device 128 shears and the net downward force causes downward movement of polished bore receptacle 102, shear ring 130 and ratchet ring 132. Shear ring 130 makes contact with packer cone 136, moving it axially downwards into packer element 138, radially expanding packer element 138 into casing string 166 and to form a fluid and pressure barrier between rubber mandrel 124 and casing string 166. The net downward force also activates hold-down slips 142 radially outwards into contact with casing string 166 to form an anchoring mechanism against upward movement of downhole tool 90 with respect to casing string 166. Applied compressive force on polished bore receptacle 102 and packer assembly 122 is retained by ratchet rings (132,134) transferring reaction forces to ratchet thread 186 on the rubber mandrel 124. The reaction forces on rubber mandrel 124 are transferred to slip cone 146, ratchet housing 150, ratchet ring 148 and into ratchet thread 188 on mandrel 106. Upward forces on mandrel 106 are conveyed from mandrel 106 to ratchet thread 188 on mandrel 106 into ratchet ring 148, into ratchet housing 150, into slip cone 146, into hold down slips 142 and into casing string 166.

[0029] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A downhole tool, comprising: a. a mandrel configured to be coupled to a running string from above and a liner string from below, the mandrel containing one or more ports extending radially through a wall of the mandrel; b. a first piston, disposed concentrically around the mandrel and axially above the one or more ports; c. a second piston, disposed concentrically around the mandrel and axially below the one or more ports; d. a polished bore receptacle assembly, disposed concentrically around the first piston and the second piston; e. a packer assembly, disposed concentrically around the mandrel and axially below the second piston; and f. a liner hanger assembly, disposed concentrically around the mandrel and axially below the packer assembly.

2. The downhole tool of claim 1, wherein the first piston is coupled to the mandrel such that the first piston is stationary.

3. The downhole tool of claim 1, wherein the polished bore receptacle assembly is received radially around the first piston and the second piston to form a hydraulic cylinder chamber.

4. The downhole tool of claim 3, wherein the first piston comprises one or more seals configured to prevent pressure communication between the hydraulic cylinder chamber and an annular space disposed axially above the first piston between the mandrel and the polished bore receptacle assembly.

5. The downhole tool of claim 3, wherein the second piston comprises one or more seals configured to prevent pressure communication between the hydraulic cylinder chamber and an annular space disposed axially below the second piston between the mandrel and polished bore receptacle assembly.

6. The downhole tool of claim 3, wherein the second piston is configured to move independently of the polished bore receptacle assembly.

7. The downhole tool of claim 6, wherein the second piston is configured to move axially downward in an annular space between the mandrel and the polished bore receptacle assembly when exposed to tubing pressure.

8. The downhole tool of claim 6, wherein the second piston is coupled with the packer assembly such that they are axially co-moving.

9. The downhole tool of claim 1, wherein the packer assembly comprises an element assembly and one or more lock rings, configured such that axial movement is constrained to a downward axial direction.

10. The downhole tool of claim 9, wherein the liner hanger assembly is coupled with the packer assembly such that they are axially co-moving.

11. The downhole tool of claim 1, wherein the liner hanger assembly comprises a hanger slip assembly and a lock ring, configured such that axial movement is constrained to a downward axial direction.

12. The downhole tool of claim 1, wherein the mandrel contains an internal profile disposed axially below the liner hanger assembly to be releasably connected to a running string above to surface.

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