Expandable stinger usable with an expandable hanger

Abstract

A method and apparatus for lowering a tieback string and an expandable stinger on top of an expandable hanger that was previously expanded in the well. The expandable stinger is expanded inside the expanded portion of the expandable hanger to seal the stinger against the expandable hanger and connect the expandable stinger to the expandable hanger. The expansion may be done through the use of a cone or swage that is able to reduce in diameter after expansion is complete to be retrievable through the tieback / restrictions above.

Description

EXPANDABLE STINGER USABLE WITH AN EXPANDABLE HANGERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to US provisional application serial no. 63 / 668,882, filed on July 9, 2024, which is incorporated herein by reference.FIELD OF THE INVENTION

[0002] The disclosure relates generally to apparatus and methods for completing a well. The disclosure relates more specifically to apparatus and methods for expanding a stinger of an upper completion inside a hanger of a lower completion that was previously expanded in the well.BACKGROUND

[0003] Typically, a solid receptacle and a solid stinger are used to connect an upper completion to a lower completion when a seal between the upper completion and the lower completion is required. In some installations, a lower completion comprises a liner and a hanger attached above the liner. The hanger is a steel tubular that often includes a top packer and slips that anchor the liner inside a well casing far below a wellhead. The top packer seals the annulus between the liner and a well casing. A receptacle, or a machined tubular having a smooth, seal finish inner surface, is connected to the upper end of the lower completion. The upper completion comprises a tieback string and a solid stinger attached below the tieback string. The solid stinger is a steel tubular with seals on the outside that is attached to the lower end of the tieback string.

[0004] Tying an upper completion to a lower completion thus usually requires anchoring the liner using a hanger, connecting the receptacle on top of the hanger, and then running the tieback string and solid stinger into the well. The solid stinger is stabbed into the solid receptacle. Using the solid receptacle and the solid stinger to connect the upper completion to the lower completiontypically involves several parts that need to be precisely machined, and as such, increases the cost of completing the well.

[0005] Because the solid stinger stabs into the solid receptacle, its pass-through inner diameter is often significantly smaller than the inner diameter of the liner. As such, this pass-through inner diameter may be insufficient in some applications. In certain applications, the pass-through inner diameter is made larger by reducing the thickness of the stinger and the thickness of the receptacle. However, this thickness reduction increases the risk of burst or collapse of the receptacle-stinger connection in cases of large pressure differentials across the completion system. This risk is exacerbated by the lack of radial support of the receptacle by the well casing.

[0006] Furthermore, in some applications, for example, in injector wells, there may be large thermal gradients that could result in pipe expansion / contraction, and anchoring loads may be extremely high. Some existing commercial products incorporate a snap ring, collet, or other member on the stinger that engages with the receptacle to create a locking function. However, the snap ring, collet, or other member may be insufficient to form a liquid / gas tight seal, and to withstand the loads placed on connection between receptacle and the stinger.

[0007] In view of the foregoing, there is a need in the art for apparatus and methods for connecting an upper completion to a lower completion to complete a well.SUMMARY

[0008] The disclosure describes a method for completing a well.

[0009] The method comprises the step of lowering an expandable hanger and a liner in the well, and expanding the expandable hanger to anchor the liner in a well casing. The method comprises the step of lowering a tieback string and an expandable stinger on top of the expandable hanger that was previously expanded in the well. The method comprises the step of expanding theexpandable stinger inside the expanded portion of the expandable hanger to seal the stinger against the expandable hanger and connect the expandable stinger to the expandable hanger.

[0010] The method may eliminate the requirement to run a separate receptacle by using the postexpanded inner surface of the expandable hanger as a receptacle. This elimination can reduce the number of parts and the machining cost of the well completion.

[0011] By using nested expandable tubulars, the method may provide superior anchoring and sealing capacity compared to conventional, anchoring tieback string systems. This improvement can be achieved by providing a long sealing length of greater than 10 feet to form a liquid / gas tight seal, and to withstand the loads placed on the connection between the expandable stinger and the expandable hanger. In contrast to a snap ring, collet, or other member to create a locking function, a long sealing length of greater than 10 feet can achieve anchoring capacity loads greater than the axial loads induced by thermal gradients within the well.

[0012] Due to the same axial position of the expandable stinger seals and the expandable hanger seals in the well, these seals provide continuous radial support across well casing, expandable hanger, and expandable stinger. Thus, the connection can be supported in burst and collapse and may achieve much higher burst and collapse ratings than previously known.

[0013] It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention.Exemplary embodiments of components, arrangements, and configurations are described below to simplify the disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For a more detailed description of the embodiments of the disclosure, reference will now be made to the accompanying drawings, wherein:

[0015] FIG. 1 is a partial sectional view of an expandable stinger assembly during deployment, prior to expansion;

[0016] FIG. 2 is a partial sectional view of the expansion assembly of an expandable stinger assembly;

[0017] FIG. 3 is a partial sectional view of an expandable stinger assembly after deployment; and

[0018] FIG. 4 is a partial sectional view of an expandable stinger deployed in an expanded hanger.DETAILED DESCRIPTION

[0019] In reference to FIG. 1, an expandable stinger assembly 100 includes a stinger 110 having external seal / anchor members 112. The lower end of stinger 110 is coupled to a shoe 130. An inner mandrel 136 is coupled to the shoe 130 and disposed inside of outer mandrel 132. An expansion assembly 120 and one or more cup seals 134 are coupled to the outer mandrel 136 and disposed in the annulus between the outer mandrel and the stinger 110. The outer mandrel 136 may be attached to the surface via drill pipe, coil tubing, or wireline (not shown). As shown in FIG. 1 and FIG. 2, expansion assembly 120 includes a solid expansion cone 122, a slidable collet 124, and a spring 126.

[0020] The expandable stinger 110 is generally run into a well casing 102 on the bottom of a long tieback string. The tieback string often has a tieback hanger on the top, which is located in a profile within the wellhead or near the wellhead. The expandable stinger 110 is spaced out suchthat a majority of the length is stabbed into the post-expanded ID of a previously installed expandable hanger 104.

[0021] The expandable stinger assembly 100 performs the function of expanding the stinger 110 through plastic deformation to a larger OD / ID and compress the outer seals / anchors 112 into a preexisting expanded expandable hanger 104. The expansion is performed using expansion assembly 120 or other swage component that can be formed into a larger diameter useful for expansion, or begins at a large diameter to perform expansion, and once expansion of the expandable stinger is complete, the cone or swage is able to reduce in diameter to be retrievable through the tieback / restrictions above.

[0022] Generally, the tieback string is not cemented in place. Once the stinger assembly 100 is latched into or near the wellhead, mechanical pull or hydraulic pressure, or a combination of the two may be used to force the expansion assembly 120 through the expandable stinger 110 to outwardly plastically deform the stinger body. The exterior of the expandable stinger has a series of metal and elastomer anchoring and sealing elements 112. Expansion causes these elements 112 to contact, compress, and deform into the previously installed expandable hanger 104. Benefits of using this method of expansion and cladding may include achieving a highly robust seal between the expandable stinger and the receptacle, creating a connection with extremely high anchoring load ratings, potentially up to the parting load of the liner itself, or both.

[0023] The size of the swage or cone 122 used to perform the expansion of the expandable stinger may be too large to pass through the tieback string above the expandable stinger. In order to retrieve the expansion assembly 120 used to perform the expansion of the expandable stinger 110, the cone 122 is preferably collapsible or capable of un-forming or shifting into a smaller diameter geometry.

[0024] In certain embodiments, a collet or thin shroud 124 surrounds the outside of the solid steel cone 122. This collet 124 cannot separate from the cone 122 until adequate radial space is available. The cone 122 is mechanically biased (by a spring 126 in this case) such that the collet is attempting to separate from the body of the cone. Once the cone 122 completes the expansion, it moves into a cavity 128 (see FIG. 3) of sufficient radial space above the expandable stinger 110. This allows the spring 126 to separate the collet 124 or shroud from the cone body 122. The cone body 122 has a sufficiently small diameter to be retrieved through the liner 140 above. The collet or shroud 124 can flex through the smaller ID liner 140 above during retrieval.

[0025] FIG. 3 illustrates the retrieval of the expansion assembly 120 and shoe 130. If using a hydraulic method for expansion, the shoe 130 is preferably retrievable to avoid leaving a restriction in the completion. The shoe 130 has a threaded collet 142 and is locked to the expandable stinger 110 in the downward direction to reduce the reaction forces due to expansion pressure. Applying an upward pull force to liner 140 dislodges the collet 142 and allows the retrieval of the shoe 130 with liner 140.

[0026] FIG. 4 illustrates a preferred embodiment of an expanded stinger 110 of an upper completion that is expanded inside a hanger 104 of a lower completion that was previously expanded in a well casing 102. Generally, an expandable stinger may be used for the purposes of sealing the expandable stinger to the expandable hanger, tying an upper completion to a lower completing anchored in a well, or other operations where a seal between upper and lower completions may be required. In certain applications, it is also desirable to anchor the expandable stinger to the expandable hanger.

[0027] In certain applications, for example, in injector wells where there may be large thermal gradients that could result in pipe expansion / contraction, anchoring loads may be extremely high.In these applications, a long expansion length of greater than 10 feet may be required to provide anchoring and sealing members 112 along the length of the stinger in sufficient quantities to form both a liquid / gas tight seal and achieve anchoring loads which may withstand the loads placed on the liner due to thermal expansi on / contracti on.

[0028] Another benefit of such a system is that the stinger seals 112 are located in the same axial location along the wellbore as the seals 150 between the hanger 104 and the casing 102. This eliminates any unsupported burst and collapse sections between the stinger and the already installed hanger. Traditionally, the stinger is located within a receptacle above the liner-top packer, and the distance between the stinger seals and the liner-top packer seals represent a thin wall steel member which may be subjected to pressure differentials beyond the burst and collapse rating of the tubular. By locating these nested seals in the same axial position, this failure mode is mitigated. Expanding the stinger also allows for a larger pass-through diameter. The pass-through diameter of the nested expandable stinger 110 within the expanded hanger 104 can be maximized.

[0029] Specific embodiments of the invention are shown by way of examples in the drawings and description. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

Claims

What is claimed is:

1. A method comprising: assembling an expansion assembly and an expandable stinger; disposing the expandable stinger in a hanger in a wellbore; moving the expansion assembly axially through the expandable stinger away from the hanger to radially expand the expandable stinger and compress a sealing member between the expandable stinger and the hanger; reducing an outer diameter of the expansion assembly after the expandable stinger is radially expanded; and removing the expansion assembly from the wellbore.

2. The method of claim 1, wherein the compression of the sealing member anchors the expandable stinger to the hanger.

3. The method of claim 1, wherein the expansion assembly is moved axially using hydraulic force.

4. The method of claim 1, wherein removing the expansion assembly from the wellbore further comprises releasing the expansion assembly from the expandable stinger.

5. The method of claim 1, wherein the expansion assembly comprises a solid cone disposed within a flexible collet.

6. The method of claim 5, wherein the outer diameter of the expansion assembly is reduced by removing solid cone from within the flexible collet.

7. An apparatus comprising: a shoe; an expandable stinger releasably coupled to the shoe; a sealing element disposed about an outside diameter of the expandable stinger; a mandrel coupled to the shoe and disposed within the expandable stinger; a solid cone coupled to the mandrel and disposed within an annulus between the expandable stinger and the mandrel; a flexible collet disposed between the solid cone and the expandable stinger; and a biasing member disposed between the solid cone and the flexible collet and configured to urge the collet away from the solid cone.

8. The apparatus of claim 7, further comprising a threaded collet that releasably couples the expandable stinger to the shoe.

9. The apparatus of claim 7, further comprising a liner coupled to the expandable stinger.

10. The apparatus of claim 9, wherein the liner has a minimum inner diameter that is less than the diameter of the flexible collet when the solid cone is disposed withing the flexible collet.

11. An assembly comprising:a lower completion including a hanger at its upper end; a hanger seal compressed between the hanger and a well casing: an upper completion having an expandable stinger disposed on its lower end; and a stinger seal compressed between an outer surface of the stinger and an inner surface of the hanger by radial expansion of the expandable stinger within the hanger.

12. The assembly of claim 11, wherein the hanger seal and the stinger seal are axially colocated within the well casing.

13. The assembly of claim 11, wherein the upper completion includes a liner having a minimum inner diameter less than an inner diameter of the expandable stinger.

14. The assembly of claim 11, wherein the hanger is an expandable hanger.

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