Tieback liner section
The tieback liner section with a frangible barrier simplifies the tieback operation by enabling direct cement pumping and pressure testing, enhancing well integrity and reducing operational complexity.
Patent Information
- Authority / Receiving Office
- US · United States
- Patent Type
- Applications(United States)
- Current Assignee / Owner
- INTERWELL NORWAY AS
- Filing Date
- 2023-12-08
- Publication Date
- 2026-07-23
Smart Images
Figure US20260210214A1-D00000_ABST
Abstract
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a tieback liner section for insertion into a liner receptacle in a well. The present invention also relates to a system for performing a tieback operation in a well. The present invention also relates to a method for performing a tieback operation in a well.BACKGROUND OF THE INVENTION
[0002] A well in which a tieback operation is to be performed is illustrated schematically in FIG. 1. The well here comprises an upper casing UC below a well head WH, and a lower production liner LL hung off at a liner hanger LH in the lower end of the upper casing UC. Below the production liner LL, the well is illustrated as an open hole. In the annulus A below the liner hanger LH, a packer P is provided. In the upper end of the production liner LL, above the liner hanger LH, a receptacle R is shown. This receptacle is often referred to as a polished bore receptacle (PBR).
[0003] An upper production liner UL indicated with dashed lines is stabbed into the receptacle R and hence form a production line between the well head WH and the lower production liner LL.
[0004] The casing shoes CS of the upper casing UC and the lower production liner LL are illustrated as solid black triangles.
[0005] A tieback operation is an operation which is performed if it is discovered that the upper casing UC has been damaged, for example by corrosion. Initially, the upper production liner UL is pulled out. In a tieback operation, a tieback liner section is inserted into the receptacle, and the annulus A between the tieback liner section and the upper casing UC is filled with cement. Hence, the damaged upper casing UC is no longer a risk with respect to the integrity of the well.
[0006] US2018355693A1 describes a wellbore liner-hanger tie-back system includes a bore receptacle coupled with a liner hanger at a downhole end of the bore receptacle, where the liner hanger is configured to be positioned in a wellbore, a tieback casing configured to be disposed in the wellbore, where a portion of an outer surface of the tieback casing is disposed proximate to an inner surface of the bore receptacle, and a seal system including at least one swellable seal. The seal system is disposed between the tieback casing and the bore receptacle to seal a space between the portion of the outer surface of the tieback casing and the inner surface of the bore receptacle.
[0007] One object of the present invention is to provide a tieback liner section for simplifying the tieback operation.
[0008] Another object of the present invention is to provide a simplified method of performing a tieback operation.SUMMARY OF THE INVENTION
[0009] The present invention relates to a tieback liner section for insertion into a liner receptacle in a well, wherein the tieback liner section comprises:
[0010] a housing having an upper end and a lower end; wherein the housing comprises a through bore provided in the longitudinal direction of the housing;
[0011] wherein the housing comprises an aperture extending radially from the bore to an outside of the housing;
[0012] wherein the lower end is insertable into the liner receptacle;
[0013] wherein the tieback liner section comprises a frangible barrier supported within the bore below the aperture.
[0014] In one aspect, the aperture is allowing cement to be pumped from the bore to an outside of the housing.
[0015] In one aspect, the liner section is a tieback liner and the liner receptacle is a polished bore receptacle.
[0016] In one aspect, the frangible barrier is extending over the entire cross section of the bore.
[0017] In one aspect, the tieback liner section comprises a barrier section comprising a barrier housing forming a subsection of the housing, wherein the barrier housing comprises a barrier seat for supporting the frangible barrier within the bore.
[0018] In one aspect, the frangible barrier comprises a cylindrical body with a chamfered upper edge and a chamfered lower edge, wherein the chamfered upper and lower edges are supported in the barrier seat.
[0019] In one aspect, the chamfered upper and lower edges of the frangible barrier are supported in complementary chamfered surfaces of the barrier seat.
[0020] In one aspect, the barrier section comprises a sealing element provided circumferentially outside of the frangible barrier.
[0021] Hence, the frangible barrier together with the sealing element are preventing longitudinal fluid flow between the upper end of the housing and the lower end of the housing.
[0022] In addition, it is possible to perform a pressure test of the tieback liner section after the tieback liner section has been cemented in place. The pressure test ensures that the tieback liner section together with the cement in the annulus is a fluid-tight barrier and capable of withstanding a predetermined fluid pressure.
[0023] In one aspect, the frangible barrier is made of glass.
[0024] Alternatively, the frangible barrier is made of ceramics, ceramic, brittle metal, polymers or dissolvable materials.
[0025] In one aspect, the frangible barrier is made of hardened glass.
[0026] In one aspect, the frangible barrier is configured to be supported within the bore during a pressure test of the liner section after the liner section (10) has been cemented in place.
[0027] The present invention also relates to a system for performing a tieback operation in a well, wherein the system comprises:
[0028] a tieback liner section as defined above;
[0029] a cement pump for pumping a cement slurry into the tieback liner section;
[0030] a wiper for guiding the cement slurry into the tieback liner section and radially out through the aperture;
[0031] a removal tool for removing the wipers and the frangible barrier when the tieback liner section has been cemented in place in the well.
[0032] As used herein, the term “wiper” is used to denote any type of barrier capable of separating a cement slurry from other fluids during movement of the wiper together with the cement slurry inside a pipe. Typically, the wiper will comprise an elastomeric material to form a seal with the inner surface of the pipe.
[0033] In one aspect, the wiper comprises a lower wiper to separate the lower well fluid in the well from the cement slurry and an upper wiper for separating the cement slurry from an upper well fluid pumped into the well above the cement slurry.
[0034] As used herein, the term “cemented in place” is used to denote that the cement slurry has been hardened into cement.
[0035] In one aspect, the further pump is configured to pump a fluid into the tieback liner section above the upper wiper for pushing the upper wiper into the tieback liner section.
[0036] In one aspect, the further pump is configured to perform a pressure test of the tieback liner section above the frangible barrier after the liner has been cemented in the well and before the removal tool has removed the wipers and the barrier.
[0037] In one aspect, the removal tool comprises a milling tool.
[0038] In one aspect, the lower wiper and / or the lower wiper comprises a frangible wiper element and a sealing material radially outside of the frangible wiper element, wherein the removal tool comprises a disintegration tool for disintegrating the frangible wiper element and the frangible barrier.
[0039] The present invention also relates to a method for performing a tieback operation in a well, wherein the method comprises the steps of:
[0040] inserting a tieback liner section as defined above into a receptacle in the well;
[0041] pumping a cement slurry into the tieback liner section and out through the aperture of the tieback liner section by means of a wiper;
[0042] removing the wiper and frangible barrier when the tieback liner section has been cemented in place in the well.
[0043] In one aspect, the method comprises the step of:
[0044] performing a pressure test of the tieback liner section above the frangible barrier after the liner has been cemented in the well and before the removal tool has removed the wiper and frangible barrier.
[0045] The terms “upper”, “above”, “below” and “lower” are used herein to define parts of the well tool device, when the well tool device is used in a well. “Upper” and “above” refer to a position relatively closer to the well opening and “below” and “lower” refer to a position relatively further away from the well opening. These terms apply both when the well has a vertical and horizontal orientation.
[0046] As used herein, the term “frangible disc” may refer to a body of a frangible material of any shape capable of being secured within a bore of the tool and capable of withstanding the pressure ratings for the tool. Due to common well geometry, the disc will typically have a circular cross-sectional shape. The height of the disc may be lower than, equal to or higher than the diameter of the disc. Hence, the terms “frangible disc” and “frangible barrier” may be used interchangeably.DETAILED DESCRIPTION
[0047] Embodiments of the invention will now be described in detail with reference to the enclosed drawings, wherein:
[0048] FIG. 1 schematically illustrates a well in which a tieback operation is to be performed;
[0049] FIG. 2 illustrates a first embodiment of the liner section;
[0050] FIG. 3 illustrates a cross sectional view of a barrier section of the liner section;
[0051] FIG. 4 illustrates the liner section inserted into the receptacle;
[0052] FIG. 5 illustrates how cement is pumped into the annulus outside of the liner section;
[0053] FIG. 6 illustrates that the liner section is cemented in place and that a barrier removal tool for removing the barrier in the liner section;
[0054] FIG. 7 illustrates that the barrier has been removed;
[0055] FIG. 8 illustrates an alternative embodiment of the wiper.
[0056] It is now referred to FIGS. 2 and 3, wherein a liner section 10, often referred to as a tieback liner, is shown. The liner section 10 is insertable into a liner receptacle R in a well, often referred to as a polished bore receptacle (often shortened as “PBR”).
[0057] The liner section 10 comprises a housing 11 having an upper end 11a and a lower end 11b, wherein the lower end 11b is insertable into the liner receptacle R. It should be noted that the housing 11 may comprise several subsections secured to each other.
[0058] The housing 11 is provided with a through bore 12 provided in the longitudinal direction CA of the housing 11. As shown in FIG. 2, the housing 11 comprises an aperture 30 extending radially from the bore 12 to an outside OS of the housing 11. When the liner section 10 is installed in the well, the outside OS is typically referred to as an annulus A (see FIG. 1, FIG. 4 etc.)
[0059] The liner section 10 comprises barrier section 20 as indicated in FIG. 2. This barrier section 2 is shown further in detail in FIG. 3.
[0060] The barrier section 20 comprises a subsection of the housing 11 in the form of a barrier housing 21. The bore 12 is provided also through the barrier housing 21. The barrier housing 21 comprises a barrier seat 24 for supporting a frangible barrier 25 within the bore 12. As shown in FIGS. 2 and 3, the frangible barrier 25 is located below the aperture 30.
[0061] The frangible barrier 25 is made of hardened glass and is shaped as a cylindrical body with a chamfered upper edge 25a and a chamfered lower edge 25b. The seat 24 comprises complementary chamfered surfaces, allowing the chamfered upper and lower edges of the frangible disc 25 to be supported in the barrier seat 24. The barrier section 20 further comprises a sealing element 26 in the form of two O-rings circumferentially outside of the frangible barrier 25, i.e. between the seat 24 and the barrier 25. Hence, the frangible barrier 25 together with the sealing element 26 are preventing longitudinal fluid flow between the upper end 11a of the housing 11 and the lower end 11b of the housing 11. The frangible barrier is capable of transferring forces caused by both positive and negative pressure differences over the frangible barrier to the housing via the chamfered surfaces of the barrier and the chamfered surfaces of the seat.
[0062] It should be noted that the liner 10 typically comprises subsections 15 comprising debris barriers and seal stacks etc. These features of the liner 10 are considered known for a person skilled in the art and will not be described further in detail herein.The Tieback Operation
[0063] The tieback operation will now be described in detail.
[0064] The situation is as described with reference to FIG. 1 in the introduction above, i.e. the upper casing UC has been damaged and the upper production liner UL is pulled out.
[0065] It is now referred to FIG. 4. Here, the liner section 10 has been inserted into the receptacle R, in which the upper production liner UL previously was inserted into. As shown, the aperture 30 is located above the receptacle R.
[0066] In a next step (FIG. 5) a cement slurry is pumped into the well by means of a cement pump 110. Typically, this is performed by using a lower wiper 120a to separate the cement from the well fluid present in the well before the cementing operation starts. The lower wiper 120a is then moved together with the cement down to an area below the aperture 30 and above the frangible barrier 25. The cement is then pumped out through the aperture 30 and into the outside OS of the housing 11, which here is the annulus A. The cement will be pumped further up to the surface again, as indicated with a dashed arrow CF in FIG. 5.
[0067] It should be noted that the cement typically will be heavier than the fluid in the annulus. Hence, the cement will also flow down to the packer P.
[0068] It is also shown in FIG. 5 that an upper wiper 120b is used to separate the cement column from a further fluid FF (indicated by solid arrow above the second wiper 120b) which is used to force most of or all of the cement into the annulus A. This further fluid FF is pumped into the well by means of a further pump 115.
[0069] The pumping of the further fluid FF is stopped when the upper wiper 120b arrives at the aperture 30. Preferably, the upper wiper 120b is now located adjacent to the lower wiper 120a, as indicated in FIG. 6. In FIG. 6, the liner section 10 now has been cemented in place, as indicated by the grey pattern.
[0070] A pressure test may now be performed by means of the further pump 115, to test if the liner section 10 together with the cement in the annulus is a fluid-tight barrier and capable of withstanding a predetermined fluid pressure.
[0071] In FIG. 6 it is also shown that a removal tool 130 has been lowered into the well W for the purpose of removing the wipers 120a, 120b and the frangible disc 25. The removal tool 130 may be a milling tool. As the wipers typically are made of an elastomeric material, and as the frangible glass disc will disintegrate as soon as the milling tool starts milling the disc, the milling operation is considered to take relatively short time.
[0072] As shown in FIG. 7, the well bore of the liner section 10 is now a part of the well bore of the well.
[0073] It is now referred to FIG. 8. Here, each wiper 120a, 120b is shown to comprise a frangible wiper element 125 and a sealing material 124 radially outside of the frangible wiper element 125, which sealingly engages the well bore during movement of the wipers in the well bore. The frangible wiper element 125 may also be a hardened glass disc. By using these wipers, the removal tool 130 may be a disintegration tool in the form of a spear etc. which can be lowered onto the frangible wiper element 125 and frangible barrier 25 for disintegrating the frangible wiper element 125 and the frangible barrier 25.
Claims
1. A tieback liner section for insertion into a liner receptacle in a well, wherein the tieback liner section comprises:a housing having an upper end and a lower end; wherein the housing comprises a through bore provided in the longitudinal direction of the housing;wherein the housing comprises an aperture extending radially from the bore to an outside of the housing;wherein the lower end is insertable into the liner receptacle;wherein the tieback liner section comprises a frangible barrier supported within the bore below the aperture.
2. The tieback liner section according to claim 1, wherein the tieback liner section comprises a barrier section comprising a barrier housing forming a subsection of the housing, wherein the barrier housing comprises a barrier seat for supporting the frangible barrier within the bore.
3. The tieback liner section according to claim 2, wherein the frangible barrier comprises a cylindrical body with a chamfered upper edge and a chamfered lower edge, wherein the chamfered upper and lower edges are supported in the barrier seat.
4. The tieback liner section according to claim 2, wherein the barrier section comprises a sealing element provided circumferentially outside of the frangible barrier.
5. The tieback liner section according to claim 1, wherein the frangible barrier is made of glass.
6. The tieback liner section according to claim 5, wherein the frangible barrier is made of hardened glass.
7. The tieback liner section according to claim 1, wherein the frangible barrier is configured to be supported within the bore during a pressure test of the liner section after the liner section has been cemented in place.
8. A system for performing a tieback operation in a well, wherein the system comprises:a tieback liner section for insertion into a liner receptacle in the well, wherein the tieback liner section comprises:a housing having an upper end and a lower end; wherein the housing comprises a through bore provided in the longitudinal direction of the housing;wherein the housing comprises an aperture extending radially from the bore to an outside of the housing;wherein the lower end is insertable into the liner receptacle;wherein the tieback liner section comprises a frangible barrier supported within the bore below the aperture;a cement pump for pumping a cement slurry into the tieback liner section;a wiper for guiding the cement slurry into the tieback liner section and radially out through the aperture;a removal tool for removing the wipers and the frangible barrier when the tieback liner section has been cemented in place in the well.
9. The system according to claim 8, wherein a further pump is configured to pump a fluid into the tieback liner section above the upper wiper for pushing the upper wiper into the tieback liner section.
10. The system according to claim 9, wherein the further pump is configured to perform a pressure test of the tieback liner section above the frangible barrier after the liner has been cemented in the well and before the removal tool has removed the wipers and the barrier.
11. The system according to claim 8, wherein the removal tool comprises a milling tool.
12. The system according to claim 8, wherein the lower wiper and / or the lower wiper comprises a frangible wiper element and a sealing material radially outside of the frangible wiper element, wherein the removal tool comprises a disintegration tool for disintegrating the frangible wiper element and the frangible barrier.
13. A method for performing a tieback operation in a well, wherein the method comprises:inserting a tieback liner section into a receptacle in the wellwherein the tieback liner section comprises:a housing having an upper end and a lower end; wherein the housing comprises a through bore provided in the longitudinal direction of the housing;wherein the housing comprises an aperture extending radially from the bore to an outside of the housing;wherein the lower end is insertable into the liner receptacle;wherein the tieback liner section comprises a frangible barrier supported within the bore below the aperture;pumping a cement slurry into the tieback liner section and out through the aperture (30) of the tieback liner section by means of a wiper;removing the wiper and frangible barrier when the tieback liner section has been cemented in place in the well.
14. The method according to claim 13, wherein the method further comprises:performing a pressure test of the tieback liner section above the frangible barrier after the liner has been cemented in the well and before the removal tool has removed the wiper and frangible barrier.