US20210040798A1

US20210040798A1 - Self-latching mechanism for securing a drilling rig floor

Info

Publication number: US20210040798A1
Application number: US16/531,375
Authority: US
Inventors: Darrell D. Jamison; Mohamed Dessoukey
Original assignee: Schlumberger Technology Corp
Current assignee: Schlumberger Technology Corp
Priority date: 2019-08-05
Filing date: 2019-08-05
Publication date: 2021-02-11
Also published as: WO2021026194A1

Abstract

A drilling rig includes a base configured to support the drilling rig, and a rig floor configured to support a mast, the rig floor being pivotally coupled to the base. The rig floor has a lowered position in which the rig floor is proximal to the base, and a raised position in which at least a portion of the rig floor is raised away from the base. The drilling rig also includes a self-latching mechanism coupled to the base and the rig floor. The self-latching mechanism is configured to latch the rig floor to the base when the rig floor is moved to the lowered position and, when latched, to prevent the rig floor from being raised to the raised position.

Description

BACKGROUND

Drilling rigs are made up of several different structural systems, which may be generally broken down into a mast, central section, and substructure (among others). These systems, and even component parts thereof, may be too large to transport to and between well sites while assembled together. Accordingly, the different component systems of the drilling rig may be disassembled, transported to a wellsite, and assembled at the wellsite.
For example, a “rig-up” sequence may include positioning the substructure at the well, attaching the rig floor (which may be rigged down during assembly), and then attaching the mast to the rig floor. The mast may be made of several sections, which may be connected together, end-to-end while the lowest section of the mast is connected to the rig floor. For example, the lowest section of the mast may be held in a horizontal orientation, parallel to the ground, and pivotally connected to the rig floor. Subsequent sections may be connected to this lower section, e.g., one after the other, thereby extending the mast, which may continue to be in the horizontal orientation. When the mast is assembled, the mast may then be raised, pivoting upwards from the horizontal orientation to a vertical orientation, e.g., while the rig floor remains in the rig-down or “lowered” position. Once the mast is raised, the rig floor may then be raised from the ground by extending the substructure.
Since the rig floor is movable up and down relative to the substructure, and the mast is likewise raiseable, the rig floor is generally secured in place to a base (or “baseboxes”) of the substructure temporarily, prior to raising the mast, until after the mast is raised. Occasionally, however, rig operators inadvertently omit to make this temporary connection between the rig floor and the baseboxes, and attempt to raise the mast with the rig floor unsecured. The result may be the rig floor unexpectedly moving along with the mast, which can damage or even lead to dropping the mast.

SUMMARY

This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
Embodiments of the disclosure may provide a drilling rig that includes a base configured to support the drilling rig, and a rig floor configured to support a mast, the rig floor being pivotally coupled to the base. The rig floor has a lowered position in which the rig floor is proximal to the base, and a raised position in which at least a portion of the rig floor is raised away from the base. The drilling rig also includes a self-latching mechanism coupled to the base and the rig floor. The self-latching mechanism is configured to latch the rig floor to the base when the rig floor is moved to the lowered position and, when latched, to prevent the rig floor from being raised to the raised position.
Embodiments of the disclosure may further provide a method including connecting a rig floor to a base and lowering the rig floor toward the base. Lowering the rig floor causes a self-latching mechanism to move from an unlatched configuration to a latched configuration, and the self-latching mechanism in the latched configuration substantially prevents the rig floor from being raised away from the base. The method also includes raising a mast that is in connection with the rig floor while the self-latching mechanism is in the latched configuration.
Embodiments of the disclosure may also provide a self-latching mechanism for a drilling rig. The self-latching mechanism includes a boot pivotally connected to a rig floor of the drilling rig, the boot comprising a hook, and a block coupled to a base of the drilling rig. The boot is configured to pivot by engagement with the block when the rig floor is lowered toward the base. The hook is configured to receive and latching onto at least a portion of the block when the rig floor is lowered to a lowered position with respect to the base. The hook receiving and latching onto the at least a portion of the block substantially prevents the rig floor from being raised away from the base.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present teachings and together with the description, serve to explain the principles of the present teachings. In the figures:

FIG. 1 illustrates a perspective view of a drilling rig, according to an embodiment.

FIG. 2 illustrates a side, perspective view of a substructure and rig floor of the drilling rig, according to an embodiment.

FIG. 3 illustrates a simplified, side view of the rig floor and a basebox of the substructure of the drilling rig, with the rig floor in a raised position, according to an embodiment.

FIG. 4 illustrates a simplified, side view of the rig floor and the basebox, with the rig floor being moved (lowered) toward the basebox, according to an embodiment.

FIG. 5 illustrates an enlarged side view of the rig floor and the basebox, specifically illustrating a self-latching mechanism of the drilling rig, with the rig floor continuing to be moved toward the basebox, according to an embodiment.

FIG. 6 illustrates a further enlarged side view of the rig floor and the basebox, further illustrating the self-latching mechanism in an unlatched configuration, according to an embodiment.

FIG. 7 illustrates an enlarged side view of the self-latching mechanism in a latched configuration, according to an embodiment.

FIG. 8 illustrates an enlarged side view of the self-latching mechanism in an unlatched configuration, with a lock bar in a locked position holding the self-latching mechanism in the unlatched configuration, according to an embodiment.

FIG. 9 illustrates a flowchart of a method for securing a rig floor to a basebox of a drilling rig, according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the present teachings, examples of which are illustrated in the accompanying drawing. In the drawings, like reference numerals have been used throughout to designate like elements, where convenient. The following description is merely a representative example of such teachings.
FIG. 1 illustrates a perspective view of a drilling rig 100, according to an embodiment. The drilling rig 100 may include, among other things, a substructure 102, a rig floor 104, and a mast 106. The substructure 102 includes two parallel, offset bases (e.g., baseboxes) 108, 110, which act as the connection to ground, supporting the weight of the drilling rig 100. The rig floor 104 is, in the illustrated configuration, supported above the baseboxes 108, 110 by the substructure 102, as will be described in greater detail below. Further, the mast 106 may be an elongate structure, which is coupled to and supported by the rig floor 104. The mast 106 may be initially be in a horizontal configuration, with its elongate structure generally parallel to the ground. The mast 106 may be pivotally connected to the rig floor 104 and then raised (pivoted) upright and secured in a vertical orientation to the rig floor 104.
FIG. 2 illustrates a perspective view of the substructure 102, including the baseboxes 108, 110 and a portion of the rig floor 104, according to an embodiment. In particular, the rig floor 104 is shown in a raised position, separated upwards from the baseboxes 108, 110. Legs 200 extend vertically between the rig floor 104 and the baseboxes 108, 110. The legs 200 may be pivotally connected to the rig floor 104 and the baseboxes 108, 110, which may allow for controlled movement of the rig floor 104 relative to the baseboxes 108, 110. Specifically, the rig floor 104 may be configured to be raised and lowered with respect to the baseboxes 108, 110. Raising cylinders 202, 204 may be coupled to the baseboxes 108, 110 and the rig floor 104 to provide for such raising/lowering.
FIG. 3 illustrates a simplified, side view of the rig floor 104, the basebox 108, and the legs 200, according to an embodiment. It will be appreciated that the basebox 110 may be similar in operation to the basebox 108, and a duplicate description thereof is omitted. As indicated in FIG. 3, the drilling rig 100 may additionally include a self-latching mechanism 300. The self-latching mechanism 300 may be directly connected to (connected to with at most structures designed to provide such connection being therebetween) the rig floor 104 and to the basebox 108. In some embodiments, a second, self-latching mechanism may be connected to the basebox 110 and the rig floor 104, but in other embodiments, such a second, self-latching mechanism may be omitted.
In an embodiment, the self-latching mechanism 300 may include a hook 302 and a block 304. As shown, the hook 302 may be connected to the rig floor 104, and the block 304 may be connected to the basebox 108; however, in other embodiments, the block 304 may be connected to the rig floor 104 and the hook 302 may be connected to the basebox 108. When the rig floor 104 is in the illustrated raised position, the hook 302 may be separated from and may not engage the block 304, such that the self-latching mechanism 300 does not impede movement of the rig floor 104 relative to the basebox 108. In other embodiments, the hook 302 may engage the block 304 in some manner, regardless of whether the rig floor 104 is in the raised position, but may, as mentioned above, not impede the lowering of the rig floor 104 from the raised position. The block 304 is illustrated positioned toward an end of the basebox 108, e.g., where a height of the basebox 108 decreases; however, this is merely one convenient place to position the block 304 on the basebox 108 and any other position is within the scope of this disclosure.
FIG. 4 illustrates a simplified, side view of the rig floor 104 being moved (lowered) toward the basebox 108, according to an embodiment. This may be referred to as a “rig down” procedure, in which the rig floor 104 is moved toward a “lowered” configuration in which the rig floor 104 is proximal to, e.g., laid against and directly supported by, the basebox 108. The rig floor 104 may be lowered by pivoting the legs 200, such that the rig floor 104 traverses an arc relative to the basebox 108, while remaining in a generally constant orientation, e.g., horizontal relative to the ground. The rig-down procedure may be employed, for example, prior to assembling a mast (e.g., the mast 106 of FIG. 1) onto the rig floor 104. In some embodiments, the rig floor 104 may include a padeye 400, which may include a pinhole 402 that is configured to align with a pinhole 404 of a padeye 406 of the basebox 108 when the rig floor 104 is fully lowered onto the basebox 108. Accordingly, a pin may be received through the pinholes 402, 404 to lock the rig floor 104 in position against the basebox 108. However, this manual locking may be omitted in some instances, e.g., by rig operators overlooking to make this connection. In such a circumstance, the self-latching mechanism 300 may maintain the position of the rig floor 104 relative to the basebox 108 when the mast 106 (FIG. 1) is raised.
FIG. 5 illustrates a simplified, side view of the rig floor 104, according to an embodiment. As shown, the rig floor 104 may continue to move into a lowered position, i.e., toward the basebox 108. Eventually, the rig floor 104 is brought to rest on directly on the basebox 108. It will be appreciated that the “lowered position” of the rig floor 104 may or may not involve the rig floor 104 resting directly on the basebox 108. For example, in some embodiments, the rig floor 104 may remain raised above the basebox 108 by some non-zero distance that is smaller than the distance between the rig floor 104 in the raised position and the basebox 108.
With continuing reference to FIG. 5, FIG. 6 illustrates the self-latching mechanism 300 in greater detail. The self-latching mechanism 300 is illustrated in an unlatched configuration in FIGS. 5 and 6, which may be any configuration in which the self-latching mechanism 300 does not prevent at least upward movement of the rig floor 104. As shown, the self-latching mechanism 300 includes a boot 500 that is integral with the hook 302. In other embodiments, the boot 500 may be separate from and coupled to the hook 302. The boot 500 is pinned to a padeye 502, and the padeye 502 is directly connected to the rig floor 104. The boot 500 may thus be configured to pivot freely with respect to the rig floor 104. Further, the block 304 may include a complementary hook-shaped engaging portion 504 that has a sloped top surface 506. The hook 302 of the boot 500 may be configured to slide along the sloped top surface 506 of the hook-shaped engaging portion 504 as the rig floor 104 is lowered toward the basebox 108. As such, the self-latching mechanism 300 may not impede the lowering movement of the rig floor 104 (i.e., the movement of the rig floor 104 toward the basebox 108).
As best shown in FIG. 6, the self-latching mechanism 300 may also include a lock bar 602. The lock bar 602 may be pivotally coupled to the basebox 108. Further, the lock bar 602 may be movable from a stowed position (illustrated) to a locked position, as will be described in greater detail below. In the stowed position, the lock bar 602 may not impede the movement of the boot 500. For example, the lock bar 602 may be flush against the basebox 108, as shown. In the locked position, the lock bar 602 may prevent the boot 500 from pivoting such that the hook 302 engages the engaging portion 504 of the block 304, but may not prevent the rig floor 104 from being raised away from the basebox 108, as will be described in greater detail below. Further, the boot 500 may include a lock recess 606 positioned at a distal end (away from the end pivotally connected to the rig floor 104), into which the lock bar 602 may be received in the locked position, as will be described in greater detail below.
Referring now to FIG. 7, as the rig floor 104 is continued to be lowered, the hook 302 may eventually drop over the edge of the engaging portion 504 of the block 304. Once this occurs, the boot 500 may pivot back towards the block 304, such that the hook 302 receives the engaging portion 504 of the block 304. Such pivoting back may occur because, as the rig floor 104 is lowered, the boot 500 may be pivoted away from vertical by interaction with the sloped top surface 506, such that when the hook 302 is no longer sliding against the block 304, the boot 500 swings back towards its vertical position. As such, the self-latching mechanism 300 may latch automatically, without intervention from rig operators, other equipment, etc. In some embodiments, the boot 500 could also be spring biased, and thus still latch automatically without intervention from rig operators, other equipment, etc.
The configuration of the self-latching mechanism 300 shown in FIG. 7 may be referred to as a “latched” configuration, in which the hook 302 is engaged with the engaging portion 504 of the block 304. In the latched configuration, the self-latching mechanism 300 may substantially prevent the rig floor 104 from being raised away from the basebox 108. In this context, “substantially prevent” means that the rig floor 104 is blocked from moving more than a minimal amount (e.g., due to normal play or tolerancing) away from the basebox 108.
FIG. 8 illustrates the self-latching mechanism 300 back in the unlatched configuration, according to an embodiment. As shown, the lock bar 602 may be pivoted to the locked position and received into the lock recess 606 of the boot 500. In this position, the lock bar 602 may prevent the boot 500 from swinging back toward the block 304 and into the latched configuration. The boot 500 may be manually manipulated into the unlatched configuration, in at least some embodiments. As noted above, in the unlatched configuration, the self-latching mechanism 300 may not prevent the upward displacement of the rig floor 104 from the basebox 108. Thus, the rig floor 104 may eventually be raised away from the basebox 108. As this occurs, the boot 500 may be lifted away from the lock bar 602, such that the lock bar 602 no longer prevents the boot 500 from swinging; however, the boot 500 may also be displaced away from the hook 302, such that the hook 302 slide along the top surface 506 of the block 304, rather than receiving the engaging portion 504, until eventually no longer engaging the block 304 at all.
FIG. 9 illustrates a flowchart of a method 900 for securing a rig floor 104 to a base 108 of a drilling rig 100, according to an embodiment. The method 900 may proceed by operation of an embodiment of the drilling rig 100 discussed above and shown in any of FIGS. 1-8, but various embodiments may employ other structures. The method 900 may include connecting the rig floor 104 to a base 108, as at 902. For example, the legs 200 may extend between the rig floor 104 and the base 108, making the rig floor 104 pivotally connected to the base 108 and movable between a raised and lowered position through an arc relative to the base 108.
The method 900 may then include lowering the rig floor 104 toward the base 108, as at 904. Lowering the rig floor 104 may cause the self-latching mechanism 300 to move from an unlatched configuration to a latched configuration, as indicated at 906. In addition, the self-latching mechanism 300 in the latched configuration may prevent raising the rig floor 104, e.g., until the self-latching mechanism 300 is unlatched. The latching that occurs at 906 may be accomplished solely by lowering the rig floor 104, e.g., without external intervention (e.g., a rig operator inserting a pin), mechanical operation, etc.
In a specific embodiment, lowering the rig floor causes a hook 302 of the self-latching mechanism 300 to slide along a block 304 of the self-latching mechanism 300 and then causes the hook 302 to receive an engaging portion 504 of the block 304. In particular, the hook 302 may be part of a boot 500 that is pivotally coupled to the rig floor 104, such the boot 500 pivots away from vertical as the hook 302 slides along the block 304, and then pivots back to vertical, causing the hook 302 to receive the engaging portion 504, resulting in the self-latching mechanism 300 latching. In some embodiments, a pin may also be received through pinholes 402, 404 in padeyes 400, 406 of the rig floor 104 and basebox 108, respectively, so as to secure the rig floor 104 in the lowered position.
The method 900 may proceed to raising a mast 106 in connection with the rig floor 104 while the self-latching mechanism 300 is in the latched configuration, as at 908. For example, the mast 106 may be received, e.g., in sections, in a horizontal orientation, into pivotal connection with the rig floor 104. For example, the mast 106 may have four legs, two of which may be initially connected, e.g., via pins, to the rig floor 104. A mast-raising cylinder, drawworks, or another type of crane, may then be employed to pivot the mast 106 from the horizontal orientation to a vertical orientation. In the vertical orientation, the two remaining legs may be connected to the rig floor 104, thereby retaining the mast 106 in the vertical orientation, such that the crane, cylinder, etc., may be released.
The method 900 may then include unlatching the self-latching mechanism from the latched configuration to the unlatched configuration, as at 910. In some embodiments, the self-latching mechanism 300 may be held unlatched using the lock bar 602, which may be deployed (e.g., pivoted) from its stowed position to a locked position, in which it engages a lock recess 606 formed in the boot 500 of the self-latching mechanism 300. Further, the pin may be removed from the padeyes 400, 406. Once the self-latching mechanism 300 is unlatched, the method 900 may proceed to raising the rig floor relative to the base, as at 912.
The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. Moreover, the order in which the elements of the methods described herein are illustrate and described may be re-arranged, and/or two or more elements may occur simultaneously. The embodiments were chosen and described in order to explain at least some of the principals of the disclosure and their practical applications, to thereby enable others skilled in the art to utilize the disclosed methods and systems and various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A drilling rig, comprising:

a base configured to support the drilling rig;

a rig floor configured to support a mast, the rig floor being pivotally coupled to the base, wherein the rig floor has a lowered position in which the rig floor is proximal to the base, and a raised position in which at least a portion of the rig floor is raised away from the base; and

a self-latching mechanism coupled to the base and the rig floor, wherein the self-latching mechanism is configured to latch the rig floor to the base when the rig floor is moved to the lowered position and, when latched, to prevent the rig floor from being raised to the raised position.

2. The drilling rig of claim 1, wherein the self-latching mechanism comprises a hook and a block, and wherein the hook is configured to slide along the block and then to receive at least a portion of the block and thereby latch onto the block when the rig floor is moved to the lowered position.

3. The drilling rig of claim 2, wherein the hook is pivotally connected directly to the rig floor, and wherein the block is connected directly to the base.

4. The drilling rig of claim 3, wherein the hook extends towards the base, and wherein the block extends toward the rig floor.

5. The drilling rig of claim 3, wherein the self-latching mechanism comprises a boot, the boot having an extension and providing the hook, the hook extending from the extension, wherein the block comprises a curved engaging portion, and wherein the hook is configured to slide along the engaging portion, while pivoting with respect to the rig floor, as the rig floor is lowered, until the hook falls over the engaging portion and swings into engagement with the engaging portion of the block.

6. The drilling rig of claim 2, wherein the self-latching mechanism further comprises a pivotal lock bar, wherein the pivotal lock bar is pivotal between a stowed position and a stand-by position, wherein the pivotal lock bar in the stand-by position is configured to engage the hook and prevent the hook from engaging the block, and wherein the pivotal lock bar in the stowed position is configured to allow the hook to move into and out of engagement with the block.

7. The drilling rig of claim 6, wherein the hook comprises a recess for receiving the pivotal lock bar, to retain the lock bar in engagement with the hook.

8. The drilling rig of claim 1, further comprising a pin connection between the base and the rig floor, wherein the pin connection is separate from the self-latching mechanism.

9. The drilling rig of claim 1, wherein the self-latching mechanism is configured to automatically latch the rig floor to the base as the rig floor is lowered so as to prevent the rig floor from being raised with respect to the base until the self-latching mechanism is unlatched.

10. The drilling rig of claim 1, wherein the self-latching mechanism is configured to latch the self-latching mechanism to the base solely by movement of the rig floor toward the base.

11. The drilling rig of claim 1, wherein the rig floor comprises a pivotal connection for connecting to the mast, and wherein the self-latching mechanism is configured to prevent the rig floor from lifting away from the base when the mast is pivoted from a horizontal orientation to a vertical orientation.

12. A method, comprising:

connecting a rig floor to a base;

lowering the rig floor toward the base, wherein lowering the rig floor causes a self-latching mechanism to move from an unlatched configuration to a latched configuration, and wherein the self-latching mechanism in the latched configuration substantially prevents the rig floor from being raised away from the base; and

raising a mast that is in connection with the rig floor while the self-latching mechanism is in the latched configuration.

13. The method of claim 12, further comprising:

unlatching the self-latching mechanism from the latched configuration to the unlatched configuration; and

raising the rig floor relative to the base after unlatching the self-latching mechanism.

14. The method of claim 13, wherein lowering the rig floor causes a hook of the self-latching mechanism to slide along a block of the self-latching mechanism and then causes the hook to receive an engaging portion of the block.

15. The method of claim 14, wherein the hook is coupled to a boot that is pivotally connected to the rig floor.

16. The method of claim 14, wherein unlatching the self-latching mechanism comprises moving a lock bar from a stowed position to a locked position, wherein the lock bar prevents a boot of the self-latching mechanism from pivoting towards a hook of the self-latching mechanism.

17. The method of claim 12, wherein the self-latching mechanism moves from the unlatched configuration to the latched configuration solely by lowering the rig floor towards the base, without external intervention.

18. A self-latching mechanism for a drilling rig, the self-latching mechanism comprising:

a boot pivotally connected to a rig floor of the drilling rig, the boot comprising a hook; and

a block coupled to a base of the drilling rig,

wherein the boot is configured to pivot by engagement with the block when the rig floor is lowered toward the base, wherein the hook is configured to receive and latching onto at least a portion of the block when the rig floor is lowered to a lowered position with respect to the base, and wherein the hook receiving and latching onto the at least a portion of the block substantially prevents the rig floor from being raised away from the base.

19. The self-latching mechanism of claim 18, wherein the hook is disengageable from the at least a portion of the block by pivoting the boot with respect to the rig floor, so as to unlatch the self-latching mechanism and allow the rig floor to be raised away from the base.

20. The self-latching mechanism of claim 18, wherein the block is rigidly attached to the base, such that the block is not configured to move with respect to the base.