System and method for barrier installation in a wellbore

Abstract

A system for wellbore cementing includes a latch-in float shoe or a collar 1 provided to run at the bottom of a casing 6. The system may comprise an inner string 5 running inside the casing 6 to be ce

Description

BACKGROUND OF THE INVENTION 1. Technical Field

[0001] The present disclosure relates to apparatus and methods for quick and efficient cementing for subsea wellbores. More particularly, the present invention relates to deploying a pressure barrier inside the wellbore by eliminating the need for cement filled baffle collar or shoe tracks and setting of the bridge plug. 2. Background Information

[0002] After a casing or liner has been deployed in a wellbore, it is sometimes desirable to set a pressure barrier within the casing or liner, to lock and seal from pressure in the direction of any sub-surface flow. If the casing or liner includes apertures, such as slots and / or a sand control screen, the barrier may be installed in order to fluidically isolate the apertures from another zone in the wellbore. The well barriers such as bridge plugs or cement retainers or any mechanical isolation devices isolate the lower part of the wellbore for permanently or temporarily sealing it from the upper part of the wellbore. In some conventional methods, after the casing is run into the wellbore, a bridge plug is installed to isolate a lower zone from an upper zone. Typically, the installation of the pressure barrier is achieved by running a bridge plug with a setting tool into the wellbore, setting the bridge plug in the casing or liner, or above the casing or liner, and then retrieving the setting tool from the wellbore. Because the running and setting of a casing or liner in a wellbore involves one trip into and out of the wellbore, the installation of the bridge plug requires a dedicated second trip into and out of the wellbore. The second trip, therefore, takes additional time and involves expense over and above the time and expense of running the casing or liner into the wellbore. Bridge plugs typically include gripping elements, referred to as slips, that bite into the casing or liner in order to anchor the bridge plug to the casing or liner. Hence, the slips damage the interior surface of the casing or liner. The damage caused by the slips can become susceptible to corrosion and / or stress corrosion cracking.

[0003] Thus, there is a need for an efficient system that does not make use of the bridge plug as the pressure barrier in the well, thus reducing the additional trips into and out of the wellbore. SUMMARY

[0004] The present disclosure employs the unique, patented SeaCure® subsea cementing system to deliver stabbed-in, inner string cementing for the subsea well. The present disclosure includes using a collar system, such that after cementing using the SeaCure® subsea cementing system, when disconnecting and pulling the inner string out of the collar, a barrier plug is tensionally set into the collar, and that serves to replace the bridge plug as the pressure barrier in the well. Such a robust and reliable technology saves rig time, reducing costs, risks and unproductive time thus providing a range of major operational, cost and time benefits to drilling and field development operations, whilst reducing or even eliminating many operational risks associated with cementing operations. By reducing multiple trips into the wellbore, this approach is more precise and environmentally friendly.

[0005] Hence, the present disclosure provides an efficient downhole cementing system comprising a pre-installed collar system that would replace the conventional bridge plug during cementing operations. The conventional barrier at the end of casing strings are generally the bridge plug, wherein during operations most of the cement in the shoe track must be drilled out, followed by a second scraper or clean-out run, then finally run and set the bridge plug in the area that has been cleaned out in the shoe track. A pre-installed collar system is designed such that it allows cementation with the SeaCure® patented method, then as the inner string is disconnected and being pulled out of the collar, an integral barrier plug is tensionally set into the collar and that serves to replace the bridge plug as the pressure barrier in the well, thus eliminating the need for shoe tracks, providing improving cement placement, drill out performance and reducing the need for remedial cementing. Contrary to conventional methods, a separate drill / clean-out trip, required to access a portion of the shoe track to properly locate the plug / barrier, is eliminated. The present system allows minimal shoe track length and a gas-tight barrier system, thus eliminating the need to drill out any shoe track, make a scraper / clean-out run and perform a secondary run in the casing to set a bridge plug, thus saving the operator multiple days of rig time.

[0006] In some examples, a collar system for wellbore cementation is described. The collar system may comprise a latch-in float shoe, or a collar provided to run at the bottom of a casing. The system may comprise an inner string running inside the casing to be cemented until a latch-in adaptor engages into a receptacle or a drill pipe latch-in receiver. The inner string may include a tool which allows its full rotation, which may ensure make-up of the casing running tool to the casing. Full rotation of the inner string may allow for safe make-up of the casing running tool to the casing. The inner string may be disconnected and pulled out of the collar, such that a barrier plug is tensionally set into the collar.

[0007] The inner string in the casing may supply cement or settable material to a casing annulus. This may allow hardening of the settable material to secure or seal the casing in the drilled bore. The system may be configured such that fluid flowing through the inner string and into the outer annulus facilitates translation of the casing into a drilled bore, or cleaning of the bore.

[0008] The collar may include a barrier plug receiver. The collar may include the drill pipe latchin receiver. In some examples, the system may be configured such that as the inner string is pulled back, the barrier plug is tensionally set into a sealing and locking position in the collar. This may serve to replace the bridge plug as a pressure barrier in the well.

[0009] The barrier plug may comprises a double-acting lock-ring to seal the barrier plug with the inner diameter of the collar, which may provide a bi-directional pressure containment.

[0010] The system may comprise a minimal shoe track length and a gas-tight barrier system. This may eliminate the need to drill out the shoe track, perform a scraper or clean-out run, and perform a secondary run in the casing to set a bridge plug. This may thereby reducing the overall time required for wellbore completion.

[0011] The system may be configured to reduce rig time with the minimal shoe track length and gas-tight barrier system.

[0012] In some examples, there is described a method for wellbore cementation.

[0013] The method may comprise running a latch-in float shoe or a collar on the bottom of a casing. The method may comprise running an inner string inside the casing to be cemented until a latch-in adaptor engages into a receptacle or a drill pipe latch-in receiver. The method may comprise allowing full rotation of an inner string for safe make-up of a casing running tool to the casing. The method may comprise running a collar system so that, as the inner string is disconnected and pulled out of the collar, a barrier plug is tensionally set into the collar.

[0014] In some examples, the inner string may include a tool, which may be stroked partially closed, and which may allow for full rotation for safe make-up of a casing running tool to the casing.

[0015] The inner string may be extend into the casing to supply cement or settable material to a casing annulus.

[0016] The method may further comprise flowing fluid through the inner string and into the outer annulus, which may facilitate translation of the casing into a drilled bore, or cleaning of the bore.

[0017] The method may comprise flowing a settable material into the outer annulus to fill the outer annulus at least partially. The method may comprise allowing hardening of the settable material to secure or seal the casing in the drilled bore.

[0018] The barrier plug may be tensionally set into a sealing and locking position in the collar, which may serve to replace the bridge plug as a pressure barrier in the well.

[0019] The method may comprise engaging the barrier plug to seal the inner diameter with a double-acting lock-ring for a bi-directional pressure containment. The bi-directional pressure containment may be within range of 10-15 ksi at 400° F.

[0020] The barrier plug and seals may be protected from flow erosion, e.g., by latch-in receiver and extended bore.

[0021] The method may comprise shearing off the barrier plug stem from the barrier plug, which may help retrieve the inner string and the latch-in adaptor.

[0022] The process may comprises of a single trip for setting casing or liner and installing a barrier Plug.

[0023] In some examples, the baffle collar may remain free of cement, which may effectively prevent pressure from below the collar from entering the casing after cementing.

[0024] In further examples, there is described an apparatus for wellbore cementation.

[0025] The apparatus may comprise a latch-in float shoe or a collar on the bottom of a casing. The apparatus may comprise an inner string run inside the casing to be cemented until a latch-in adaptor engages into a receptacle or a drill pipe latch-in receiver. The inner string may allow for full rotation for make-up of a casing running tool to the casing. The apparatus may comprise a collar system, e.g., wherein, as the inner string is disconnected and pulled out of the collar, a barrier plug is tensionally set into the collar.

[0026] The collar may includes a barrier plug receiver and the drill pipe latch-in receiver, which may be complete with back-up release shear out feature and plug sealing mechanism.

[0027] The inner string may include a tool that can be stroked partially closed, which may allow for full rotation for safe make-up of a casing running tool to the casing.

[0028] Various features and aspects as described above, and as recited in the claims below, may be combined with one or more of the other features and aspects described herein, or may have utility independently of the other features and aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitutes a part of this specification, illustrate one or more embodiments of the present disclosure and together with the description, serves to explain the principles of the present teachings.

[0030] FIG. 1 is a sectional view of a downhole cementing system embodiment that includes a float collar with a SeaCure® latch-in profile, in accordance with the disclosure.

[0031] FIG. 2 is a sectional view of a downhole cementing system embodiment with the latch-in adaptor for inner string cementing.

[0032] FIG. 3 is a sectional view of a downhole cementing system embodiment disclosing retrieving operation of an inner string.

[0033] FIG. 4 is a sectional view of the next step of the downhole cementing system illustrating shearing to retrieve the inner-string and adaptor. DETAILED DESCRIPTION

[0034] FIG. 1 diagrammatically illustrates a downhole cementing system comprising a baffle collar 1 with a SeaCure® latch-in profile. The SeaCure® tool can then be stroked partially closed to allow full rotation of the inner string 5 and allow safe make-up of the casing running tool to the casing 6. FIG. 2 shows a casing 6 or a liner with the baffle collar 1 in the borehole. The latch-in float shoe or collar 1 consists of a barrier plug receiver 4 and drill pipe latch-in receiver 10 complete with back-up release shear out feature and plug sealing mechanism.

[0035] As illustrated in FIG. 2, an inner string 5 is extended into the casing 6 to supply the cement or settable material from the surface, the flow path 3 through the tool while cementing is indicated as an arrow in FIGS. 1 and 2. The process of the present invention avoids creation of a cement-filled baffle collar. The problem with a cement-filled baffle collar is that it does not provide a reliable barrier to pressure entering the casing after completion of the cement job, from below the baffle collar.

[0036] The inner string 5 is lowered until a latch-in adaptor 7 is engaged into a receptacle or the latch-in receiver 10 of the float collar 1, as seen in FIG. 2. The ability to flow fluid through the inner string 5 offers advantages. For example, the method may comprise flowing fluid through the inner string 5 and into the outer annulus to facilitate translation of the casing 6 into the drilled bore, or cleaning of the bore. Alternatively, or in addition, present disclosure method embodiments may comprise flowing a settable material into the outer annulus to fill the outer annulus at least partially, the settable material subsequently hardening to secure or seal the casing 6 in the drilled bore.

[0037] After the desired volume of cement slurry is pumped in through the inner string 5 into the annular region 3, while pulling out the inner string 5 from the collar 1, shear pins from collar 1 are sheared against latch-in receiver 10, and a barrier plug 2 is tensionally set into a sealing and locking position in the collar 1 and that feature serves to replace the bridge plug as the barrier in the well. When the inner string 5 is retrieved, as seen from FIG. 3, the barrier plug 2 engages in sealing the inner diameter with double-acting lock-ring for bi-directional pressure containment to 10-15 ksi at 400°F. Both seals 9 and plug 2 have been protected from flow erosion by latch-in receiver 10 and extended bore 11. The system comprises a primary shear system 12a as shown in FIG.3 and a secondary shear system 12b as shown in FIG. 4, which are sheared as the inner string is pulled out. Finally, in the last step as illustrated in FIG. 4, as the inner string is pulled out, the plug stem 8 is sheared off to retrieve inner string 5 and latch-in adaptor 7.

Claims

1. A collar system for wellbore cementation, comprising:a latch-in float shoe or a collar provided to run at the bottom of a casing;an inner string running inside the casing to be cemented until a latch-in adaptor engages into a receptacle or a drill pipe latch-in receiver;wherein the inner string includes a tool which allows its full rotation to ensure make-up of the casing running tool to the casing;wherein full rotation of the inner string allows for safe make-up of the casing running tool to the casing; andwherein as the inner string is disconnected and pulled out of the collar, a barrier plug is tensionally set into the collar.

2. The system of claim 1, comprising the inner string in the casing which supplies cement or settable material to a casing annulus and allowing hardening of the settable material to secure or seal the casing in the drilled bore.

3. The system of claim 1 or 2, comprising the inner string in the casing, wherein a fluid flows through the inner string and into the outer annulus to facilitate translation of the casing into a drilled bore, or cleaning of the bore.

4. The system of claim 1, 2 or 3, wherein the collar includes a barrier plug receiver and the drill pipe latch-in receiver, wherein as the inner string is pulled back, the barrier plug is tensionally set into a sealing and locking position in the collar, serving to replace the bridge plug as a pressure barrier in the well.

5. The system of any of the claims 1 to 4, wherein the barrier plug comprises a double-acting lock-ring to seal the barrier plug with the inner diameter of the collar to provide a bi-directional pressure containment.

6. The system of any of the claims 1 to 5, comprising a minimal shoe track length and a gastight barrier system, eliminating the need to drill out the shoe track, perform a scraper or clean-outrun, and perform a secondary run in the casing to set a bridge plug, thereby reducing the overall time required for wellbore completion.

7. The system of claim 6, wherein the system reduces rig time with the minimal shoe track length and gas-tight barrier system.

8. A method for wellbore cementation, the method comprising:running a latch-in float shoe or a collar on the bottom of a casing;running an inner string inside the casing to be cemented until a latch-in adaptor engages into a receptacle or a drill pipe latch-in receiver;allowing full rotation of an inner string for safe make-up of a casing running tool to the casing; andrunning a collar system so that as the inner string is disconnected and pulled out of the collar, a barrier plug is tensionally set into the collar.

9. The method of claim 8, wherein the inner string includes a tool that can be stroked partially closed to allow for full rotation for safe make-up of a casing running tool to the casing.

10. The method of claim 8 or 9, wherein the inner string is extended into the casing to supplycement or settable material to a casing annulus.

11. The method of claim 10, further comprising flowing fluid through the inner string and into the outer annulus to facilitate translation of the casing into a drilled bore, or cleaning of the bore.

12. The method of any of the claims 8 to 11, comprising flowing a settable material into the outer annulus to fill the outer annulus at least partially, and allowing hardening of the settable material to secure or seal the casing in the drilled bore.

13. The method of any of the claims 8 to 12, wherein the barrier plug is tensionally set into a sealing and locking position in the collar which serves to replace the bridge plug as a pressure barrier in the well.

14. The method of any of the claims 8 to 13, comprising engaging the barrier plug to seal the inner diameter with a double-acting lock-ring for a bi-directional pressure containment.

15. The method of claim 14, wherein the bi-directional pressure containment is within range of 10-15 ksiat400°F.

16. The method of any of the claims 8 to 15, wherein both the barrier plug and seals are protected from flow erosion by latch-in receiver and extended bore.

17. The method of any of the claims 8 to 16, further comprising shearing off the barrier plugstem from the barrier plug in order to retrieve the inner string and the latch-in adaptor.

18. The method of any of the claims 8 to 17, wherein the process comprises of a single trip for setting casing or liner and installing a barrier plug.

19. The method of any of the claims 8 to 18, wherein the baffle collar remains free of cement, thereby effectively preventing pressure from below the collar from entering the casing after cementing.

20. An apparatus for wellbore cementation, comprising:a latch-in float shoe or a collar on the bottom of a casing;an inner string run inside the casing to be cemented until a latch-in adaptor engages into a receptacle or a drill pipe latch-in receiver;wherein the inner string is allowed for full rotation for make-up of a casing running tool to the casing; anda collar system wherein, as the inner string is disconnected and pulled out of the collar, a barrier plug is tensionally set into the collar.

21. The apparatus of claim 20, wherein the collar includes a barrier plug receiver and the drill pipe latch-in receiver, complete with back-up release shear out feature and plug sealing mechanism.

22. The apparatus of claim 20 or 21, wherein the inner string includes a tool that can be strokedpartially closed to allow for full rotation for safe make-up of a casing running tool to the casing.11

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