Granted Patent B2

US 10,683,728 · App. 16/018,903 · Granted Jun 16, 2020

Abstract

Claims (44)

1. An apparatus for use in a string of tubulars, the apparatus comprising:

a first sub having a bore;

a second sub attached to the first sub, the second sub having a bore in fluid communication with the bore of the first sub;

a barrier assembly having a frangible member that is configured to break by applying a fluid pressure to the frangible member;

a misalignment feature coupled to the barrier assembly; and

one or more shearable members coupled to the barrier assembly and configured to prevent the frangible member from moving with respect to the first and second subs until at least one of the one or more shearable members yields,

wherein, when at least one of the one or more shearable members shears under a force applied by fluid pressure on the frangible member, the frangible member moves axially toward the second sub and the misalignment feature engages the second sub, causing the frangible member to tilt with respect to a central axis of the first sub, the second sub, or both.

2. The apparatus of claim 1 , wherein the frangible member is configured to break by applying the fluid pressure alone, without engagement of any mechanical devices with the frangible member.

3. The apparatus of claim 1 , wherein the barrier assembly further includes a connection member engaging the frangible member.

4. The apparatus of claim 3 , wherein the connection member comprises a ring having a plurality of tabs disposed around a circumference of the ring.

5. The apparatus of claim 4 , wherein the plurality of tabs are configured to shear from the ring at a predetermined force.

6. The apparatus of claim 4 , wherein the barrier assembly further comprises a shear ring,

wherein the shear ring abuts the connection member, so as to at least temporarily maintain a position of the connection member and the frangible member with respect to the bore,

wherein the misalignment feature extends away from an end of the shear ring, such that the misalignment feature engaging the second sub causes the shear ring to tilt, and

wherein the shear ring tilting causes the connection member to tilt, which causes the frangible member to tilt.

7. The apparatus of claim 6 , wherein the misalignment feature comprises a tab that extends axially from the end of the shear ring.

8. The apparatus of claim 6 , further comprising a housing that connects together the first and second subs, wherein the shear ring is positioned in an annulus at least partially defined radially between the second sub and the housing, the annulus being larger in axial dimension than the shear ring.

9. The apparatus of claim 1 , further including a housing between the first and second subs, wherein the barrier assembly is disposed in the housing.

10. A method of placing a string of tubulars in a wellbore, the method comprising:

installing a float sub in the string of tubulars to form an isolated portion in the string of tubulars, the float sub including:

a first sub having a bore;

a second sub attached to the first sub, the second sub having a bore in fluid communication with the bore of the first sub;

a barrier assembly having a frangible member that is configured to break by applying a fluid pressure to the frangible member;

a misalignment feature coupled to the barrier assembly; and

one or more shearable members coupled to the barrier assembly and configured to prevent the frangible member from moving with respect to the first and second subs until at least one of the one or more shearable members yields,

wherein, when at least one of the one or more shearable members shears under a force applied by fluid pressure on the frangible member, the frangible member moves axially toward the second sub and the misalignment feature engages the second sub, causing the frangible member to tilt with respect to a central axis of the first sub, the second sub, or both;

placing a low-density fluid or gas in the isolated portion of the string of tubulars;

lowering the string of tubulars into the wellbore, wherein the low-density fluid or gas creates a buoyant force in the string of tubulars to facilitate placing the string of tubulars in the wellbore; and

applying a fluid pressure in the string of tubulars to break the frangible member of the float sub after the string of tubulars is placed in the wellbore.

11. The method of claim 10 , wherein the float sub further includes a connection member attached to the frangible member, the connection member having a plurality of tabs.

12. The method of claim 11 , wherein the plurality of tabs are configured to assist the frangible member to break upon application of the fluid pressure.

13. The method of claim 11 , wherein the connection member is tunable to a specific shear force by removing a selected number of tabs.

14. The method of claim 10 , wherein applying the fluid pressure causes the one or more of the shearable members of the float sub to yield, wherein the one or more shearable members yielding results in a support ring of the float sub moving relative to a housing of the float sub, and wherein the support ring moving results in the frangible member rupturing by applying the fluid pressure.

15. The method of claim 14 , wherein the one or more shearable members, prior to yielding, hold a shear ring of the float sub in place relative to the frangible member, the shear ring supporting the support ring, and the support ring supporting the frangible member, wherein the one or more shearable members yielding allows the shear ring, the support ring, and the frangible member to move relative to the housing.

16. The method of claim 14 , wherein the shear ring comprises the misalignment feature, such that the one or more of the shearable members yielding results in an unbalanced support of the frangible member, such that the frangible member is tiled with respect to a central axis of the float sub.

17. An apparatus for use in a string of tubulars, the apparatus comprising:

a first sub having a bore;

a second sub attached to the first sub, the second sub having a bore in fluid communication with the bore of the first sub;

a barrier assembly having a frangible member that is configured to break by applying a fluid pressure to the frangible member;

means for retaining the frangible member in place with respect to the first sub, the second sub, or both, until a predetermined hydraulic pressure differential across the frangible member is reached, wherein, when the predetermined hydraulic pressure differential is reached, the means for retaining permit the frangible member to move toward the second sub; and

means for tilting the frangible member with respect to a central axis of the bore of the first sub, the bore or the second sub, or both, wherein the means for tilting engage the second sub after the means for retaining the frangible member release, causing the frangible member to tilt.

18. The apparatus of claim 17 , wherein the means for retaining comprise a plurality of shearable members coupled to the first sub, the second sub, or both and the barrier assembly.

19. The apparatus of claim 18 , wherein the barrier assembly includes a shear ring coupled to the shearable members, and wherein the means for tilting comprise a tab extending axially from the shear ring, the tab being configured to engage the second sub so as to cause the shear ring and the frangible member to tilt.

20. The apparatus of claim 17 , wherein at least a portion of the frangible member has a dome-shape, wherein, before the means for retaining release, the dome-shape of the frangible member is aligned with the bore of the first sub, the bore of the second sub, or both, such that the dome-shape distributes the fluid pressure, and wherein tilting the frangible member misaligns the dome-shape with the bore of the first sub, the bore of the second sub, or both, thereby changing a distribution of pressure on the dome-shape and reducing a pressure differential at which the frangible member ruptures.

Assignments (7)