Anti-rotation device for connector assembly

An improved anti-rotation device and connector assembly designed to prevent rotation of a first threaded portion of the connector assembly with respect to a second threaded portion of the connector assembly is provided. The anti-rotation device and connector assembly include features that guide and smooth the transition of the anti-rotation device into a position extending through the first and second threaded portions. The anti-rotation device may extend through a tab/groove interface between the first and second threaded portions, or the anti-rotation device may engage opposing interfacing edges of the first and second threaded portions along the length of the anti-rotation device. Once the anti-rotation device is installed through the first and second threaded portions, the anti-rotation device may prevent rotation of the threaded portions relative to each other.

TECHNICAL FIELD

The present disclosure relates generally to connector assemblies for coupling strings of tubular and other components and, more particularly, to anti-rotation devices used to prevent rotation of threaded connector assemblies.

BACKGROUND

Offshore oil and gas drilling operations typically include the make-up of strings of pipe or casing members, frequently of relatively large diameter. The tubular strings may be driven into the ground underwater to be used for anchoring the drilling platform. Such strings are also used as conduits in the water through which a well may be initiated. The joint between members of such tubular strings must provide both structural strength and fluid pressure integrity. Such features of a joint might be provided, for example, by welding. However, because welding is a time-consuming operation, and drilling rig rates are high, particularly offshore, mechanical connectors are generally preferred. Typical mechanical connectors available include threaded type connectors in which tubular members are mutually rotated to thread a pin and box connector assembly, breach block connectors, and snap lock connectors.

In threaded mechanical connector assemblies an externally threaded end, known as the pin, mates with an internally threaded section, known as the box. The pin and the box on a threaded connector assembly are designed to be engaged with each other and rotated to a specific torque value for connecting the ends. After the connection is made, anti-rotation devices can be installed to secure the pin and the box together at the desired make-up torque. The anti-rotation devices are designed to ensure that the threaded portions of the connector assembly do not become tightened over the desired make-up torque or loosened from each other in response to forces applied to the pipe or casing members in the string.

Existing anti-rotation devices often feature a mechanical key that can be selectively positioned in a recess between the pin and the box of the connector assembly to prevent rotation of the pin and the box relative to each other in a certain direction once the make-up torque is reached. Unfortunately, these keys typically do not go into action to engage with the connector assembly until after the connection is loosened slightly. That is, the keys are generally first positioned in the recesses of the connector assembly, and then the pin and box are rotated slightly relative to each other to energize the key. As a result, the connection may be secured at a different torque than the initial desired make-up torque.

In addition, some existing anti-rotation keys are designed to interface very closely with the connector assembly to fill a recess therein. As such, these keys can be difficult to position in the corresponding recess and often must be hammered into engagement with the connector assembly using a large amount of force. This hammering process takes an undesirable amount of time and energy to ensure that the keys are lodged into their respective recesses in the connector assembly.

DETAILED DESCRIPTION

Certain embodiments according to the present disclosure may be directed to an improved anti-rotation device and connector assembly designed to prevent rotation of a first threaded portion of the connector assembly with respect to a second threaded portion of the connector assembly. Existing systems utilize an anti-rotation key that must be hammered into a tight space and, therefore, takes an undesirable amount of time to secure within the connector assembly. In addition, some existing anti-rotation keys require a slight rotation of the threaded portions relative to each other to energize the key within a recess between the first and second threaded portions. The disclosed anti-rotation device and connector assembly include several features that facilitate easier, faster, and more accurate securing of the connector to prevent rotation of the threaded portions of the connector. For example, the connector assembly may include features that guide and smooth the transition of the anti-rotation device into a position extending through both the first and second threaded portions of the connection.

The presently disclosed anti-rotation device may include a pin, nail, spike, or other elongated feature designed to be driven through the first and second threaded portions of the connector assembly to secure the threaded portions relative to each other. The first threaded portion may include a pilot hole formed therethrough for directing the anti-rotation device into the connection. In some embodiments, the first threaded portion may include a groove formed therein, and the second threaded portion may include a tab to be received through the groove in the first threaded portion. The anti-rotation device may be designed to extend through the tab and the first threaded portion on one or both sides of the groove. In other embodiments, the pilot hole may be formed along an edge of the first threaded portion that interfaces with a mating edge of the second threaded portion, such that the anti-rotation device directly contacts both the first and second threaded portions along the entire length of the anti-rotation device upon its installation in the connection.

The disclosed anti-rotation device may be forced through the connection of the threaded portions using an installation tool such as, for example, a nail gun or other triggered mechanism. This may save time spent installing the anti-rotation device into the connector assembly, compared with existing systems that require a large amount of hammering to position a key in the connection. In some embodiments, the anti-rotation device may include a tapered pin designed to be forced through the connector assembly using a hammer. In such instances, the pilot hole may effectively guide the tapered pin, thereby decreasing the amount of time needed to install the anti-rotation device.

The disclosed installation method used for the anti-rotation device does not involve rotating the threaded portions of the connector relative to each other to energize a key, such as those used in existing systems. Instead, the installation method may enable the anti-rotation device to be positioned directly through the connector assembly with little or no clearance gap formed by rotating the threaded portions relative to each other. That is, the anti-rotation device is driven through the connector assembly in a way that reduces, minimizes, or eliminates any rotational clearance gap from the proper make-up torque for the connection.

Turning now to the drawings,FIGS. 1A and 1Billustrate a system10that includes a connector assembly12with a first threaded portion14and a second threaded portion16that may be secured in a desired rotational position relative to each other by an improved anti-rotation device18. The first threaded portion14of the connector assembly12may be an externally threaded end, known as the “pin”, while the second threaded portion16is an internally threaded section, known as the “box”. The pin and box are designed to be threaded together to connect a first tubular component (not shown) to a second tubular component (not shown). These tubular components may include, for example, lengths of a wire stem or large diameter casing.

In some embodiments, the pin is formed into the first tubular component and the box is formed into the second tubular component, such that the connector assembly12is integral to the tubular components being connected. In other embodiments, the pin and the box may be separate components that are attached to their respective tubular components as desired to facilitate the connection. However, the present disclosure is not limited to any specific configuration of the pin and box relative to the tubular components being connected.

When forming these tubular connections using the connector assembly12, it is desirable to rotate the first and second threaded portions14and16relative to each other until the connector assembly12reaches a desired make-up torque. Upon reaching this make-up torque, the connection may be secured using one or more anti-rotation devices18to prevent the threaded portions14and16from being rotated away from their designated make-up torque. As illustrated inFIGS. 1A and 1B, it may be desirable to arrange several of these anti-rotation devices18about a circumference of the connector assembly12, to ensure a secure connection around the entire boundary between the first and second threaded portions14and16.

FIG. 1Bprovides a more detailed view of the anti-rotation devices18interacting with the connector assembly12to secure the first threaded portion14relative to the second threaded portion16. In some embodiments, the first threaded portion14may include a groove20formed therein, while the second threaded portion16may include a tab22configured to be disposed through the groove20of the first threaded portion14. Once installed, the anti-rotation device18may extend through the tab22and through the first threaded portion14, in order to secure the portions of the connector assembly12in a desired rotational position. Once the anti-rotation device18is installed through the tab22and the first threaded portion14, the anti-rotation device18may prevent rotation of the threaded portions14and16relative to each other.

As illustrated, the tab22and the groove20may be oriented so that the tab22extends through the groove20in a direction substantially parallel to a longitudinal axis24of the connector assembly12. The anti-rotation device18may extend through the tab22and the first threaded portion14in a radially inward direction with respect to the axis24of the connector assembly12. It should be noted that other arrangements and angles of these components relative to each other may be utilized in other embodiments of the disclosed system10.

The illustrated tab22may be a cylindrical tab extending from the second threaded portion16all the way around the circumference of the connection. The groove20in the first threaded portion14is designed to overlap the tab22extending therethrough. As described in detail below, the first threaded portion14may include a pilot hole formed therein to guide the anti-rotation device18through the first threaded portion14and into the tab22extending through the groove20. The pilot hole may extend through the first threaded portion14on one or both sides of the groove20. The anti-rotation device18may be forced through the first threaded portion14and the tab22, guided by the pilot hole, to form a zero-tolerance rotational connection between the first and second threaded portions14and16. That is, once the anti-rotation device18is installed through both portions, the first and second threaded portions14and16cannot rotate relative to each other.

The anti-rotation device18may include any elongated structural mechanism that can be forced through the first and second threaded portions at their interface. For example, the anti-rotation device18may include a hardened nail, a pin (tapered or having a constant thickness), or a spike. The anti-rotation device18may be delivered into the connector assembly12via an installation tool or similar trigger mechanism. It may be desirable for the tab22to be at least as thick as the diameter of the anti-rotation device18being forced through the tab22. Once installed, the anti-rotation device18may secure the threaded portions14and16relative to each other in a way that prevents rotation of these parts in either direction, instead of being limited to stopping only right-hand or left-hand rotations.

Once the anti-rotation device18is installed through the tab22and the first threaded portion14, the anti-rotation device18may provide a double shear connection to prevent the connector assembly12from unlocking. That is, since the anti-rotation device18is forced through the tab/groove connection of the first and second threaded portions14and16, the anti-rotation device18would have to be sheared in two places (both sides of the tab22) to allow the connection to rotate. Thus, the anti-rotation device18provides a secure connection between the first and second threaded portions14and16due to the connection interface between the threaded portions. This may provide a stronger connection than what is currently offered through existing anti-rotation keys. In other embodiments, however, the anti-rotation device18may be extended through only one side of the first threaded portion14and the tab22to form a single shear connection.

InFIG. 1B, only two such anti-rotation devices18are illustrated, but it should be noted that in other embodiments any desirable number of anti-rotation devices18may be positioned within the connector assembly12to prevent further rotation of the threaded portions14and16. The number of anti-rotation devices18used to secure the connector assembly12may be determined based on the materials used for the first and second threaded portions14and16.

In some instances, the number of anti-rotation devices18used may be selected to achieve a desired torque resistance of the connection. For example, a larger number of anti-rotation devices18may be used when a higher torque resistance is needed for the connection. Each anti-rotation device18may provide an additional torque amount of approximately 10,000 foot pounds of torque to the connection. Thus, if a desired amount of torque resistance for the connection is 90,000 foot pounds, then the first and second threaded portions14and16may be made up to a torque of approximately 50,000 foot pounds and secured using four anti-rotation devices18that provide (in total) an additional 40,000 foot pounds of torque. The torque values are provided as illustrative examples only. Accordingly, the methods and steps disclosed herein may be implemented for different torque amounts without departing from the scope of the present disclosure.

In some embodiments, it may be desirable to include a plurality of holes30(i.e., pilot holes) formed through the first threaded portion14and used to position a desired number of anti-rotation devices18into the connector assembly12. The number of anti-rotation devices18may be less than the total number of holes30. InFIG. 1A, for example, three holes30are shown extending through an outer edge of the first threaded portion14. These holes30may be pilot holes used for guiding the anti-rotation devices18into the first threaded portion14. In the illustrated embodiment, only one anti-rotation device18is shown positioned within the middle hole30of the three holes30. The other holes30may be redundant holes that are pre-drilled into the first threaded portion14. The redundant holes30may be used to position new anti-rotation devices18if previously positioned anti-rotation devices18break during installation or are removed from the connector assembly12. It may be desirable to include at least twice as many holes30as the expected number of anti-rotation devices18to be positioned around the connector assembly12. This arrangement may make the disclosed system10relatively easy to assemble and reconfigure as desired.

It should be noted that variations on the illustrated system10may be used in other embodiments. For example, in other embodiments the pin and the box sections of the connector assembly12may be reversed, such that the box acts as the first threaded portion14having the groove20and the pin acts as the second threaded portion16having the tab22.

FIGS. 2A-2Cillustrate the connector assembly12ofFIGS. 1A and 1Bbeing secured via the anti-rotation device18.FIG. 2Aprovides a detailed view of the interface between the first threaded portion14and the second threaded portion16of the connector assembly12. As illustrated, the first threaded portion14may include the groove20cut vertically into the face designed to mate with the second threaded portion16. The first threaded portion14may include an outer ring50on one side of the groove20and an internal body52on an opposite side of the groove20. The groove20will be deep enough to receive the corresponding tab22extending from the second threaded portion16. The tab22may be shaped to interface with the groove20and to abut the outer ring50when the first threaded portion14and the second threaded portion16are mated.

The second threaded portion16may include the elongated tab22designed to be received into the groove20of the first threaded portion14. The groove20and tab22may be sized based on the strength of the materials used in the first and second threaded portions14and16. The groove20and tab22may also be sized based on the size of the threaded portions14and16that make up the connector assembly12. In some embodiments, the groove20and tab22may be sized based on the desired make-up torque needed to make the connection. Each size of connector assembly12may have different make-up torques and material requirements, so these may be generally considered when selecting the dimensions of the groove20and tab22used for the connection.

As mentioned above, the first threaded portion14may include a pilot hole30formed therethrough. The pilot hole30, as shown, may be drilled through the outer ring50and may penetrate the internal body52of the first threaded portion14. This way, the pilot hole30may extend through both sides of the groove20. The pilot hole30is designed to receive and guide the anti-rotation device through the first and second threaded portions14and16to secure the connection at a desired make-up torque.

In addition to the pilot hole30, the first threaded portion14may include a counterbore54formed along an outside surface of the outer ring50. The counterbore54may be concentric with the pilot hole30and, as discussed below, may be used to seat an installation tool designed to force the anti-rotation device into the connector assembly12. As described in detail below, some embodiments of the first threaded portion14may also include a counterbore56formed along an outside facing surface of the internal body52. This counterbore56may also be concentric with the pilot hole30and the outside counterbore54.

The pilot hole30may be drilled through only the first threaded portion14and not through the tab22extending from the second threaded portion16. This is because any pre-drilled holes formed in the tab22would be unlikely to align properly with the pilot holes30in the first threaded portion14when the connection is made up, due to tolerances on the thread make-up between the threaded portions14and16. In the illustrated embodiment, the pilot hole30through both sides of the first threaded portion14will be enough to direct the anti-rotation device through the portion of the tab22that is matched up with the hole30at the desired make-up torque.

FIG. 2Bshows an installation tool70being brought into contact with the connector assembly12to install the anti-rotation device through the first and second threaded portions14and16. The counterbore54may be used to align the installation tool70so that the anti-rotation device will be driven through the first and second threaded portions14and16in a proper alignment (e.g., following the pilot hole30). Specifically, the counterbore54may be used to fit a barrel72of the installation tool70in a proper alignment against the first threaded portion14. In some embodiments, the first threaded portion14may include the counterbore54for seating the installation tool70in a proper alignment even if there are no pilot holes drilled through the first threaded portion14.

The installation tool70may be any desirable tool that can exert a force to drive the anti-rotation device through the outer ring50, the tab22, and a portion of the internal body52. The installation tool70may utilize pneumatic pressure, hydraulic pressure, mechanical force (such as a spring force), or an explosive charge (e.g., similar to a nail gun) to drive the anti-rotation device through the layers of material that make up the connector assembly12. In other embodiments, the installation tool70may be a hammer used to mechanically drive the anti-rotation device18through the connector assembly12.

FIG. 2Cillustrates the anti-rotation device18extending through the tab22and the first threaded portion14in response to force from the installation tool70. As described above, the anti-rotation device18may be guided by the pilot hole30to extend through the outer ring50, the tab22, and into the internal body52of the first threaded portion14. As the anti-rotation device18is forced through the tab22, the anti-rotation device18may cause the material of the tab22to deform where the anti-rotation device18exits the tab22. As illustrated, the counterbore56formed on the outside face of the internal body52may be used to receive the material that is deformed and extruded from the tab22when the anti-rotation device18is installed. This material deformation extending from the tab22into the internal body52of the first threaded portion14may further increase the interference between the first and second threaded portions14and16, thereby increasing the anti-rotation capability.

In some embodiments, the installation method of using a triggered installation tool70with a barrel72may facilitate rifling of the anti-rotation device18as it moves from the installation tool70through the connector assembly12. This may further increase the interference fit between the threaded portions14and16, thereby making the connection more secure.

FIGS. 3A-4Billustrate another embodiment of the disclosed anti-rotation system10. Specifically,FIGS. 3A and 4Ashow the connector assembly12without the anti-rotation device18installed, andFIGS. 3B and 4Bshow the connector assembly12with the anti-rotation device18installed. In this embodiment, the connector assembly12may include a first threaded portion14and a second threaded portion16that interface with each other through a more traditional pin/box connection76. As illustrated inFIGS. 3A and 3B, this connection76may not include a groove and corresponding tab for interfacing the threaded portions14and16. Instead, the connection76between the two threaded portions14and16may be merely along a single longitudinal edge78.

In the illustrated embodiment, the first threaded portion14may include a pilot hole30formed therethrough to direct the anti-rotation device18into engagement with the first and second threaded portions14and16. As described above, the anti-rotation device18may include any elongated structural mechanism that can be forced through the first and second threaded portions14and16at their interface. For example, the anti-rotation device18may include a hardened nail, a pin (tapered or having a constant thickness), or a spike. The anti-rotation device18may be delivered into the connector assembly12via the installation tool70or similar trigger mechanism as described above with reference toFIGS. 2A-2C.

As illustrated inFIGS. 3A-4B, the pilot hole30may be drilled through an interfacing edge80of the first threaded portion14. The interfacing edge80may be designed to interface with or be disposed proximate to an opposing interfacing edge82of the second threaded portion16upon make-up of the connection. The pilot hole30may be drilled (and consequently the anti-rotation device18may extend) through the first threaded portion14in a radially inward direction with respect to the axis24of the connector assembly12. It should be noted that other arrangements and angles of these components relative to each other may be utilized in other embodiments of the disclosed system10.

The pilot hole30may be drilled through the interfacing edge80of the first threaded portion14such that at least a portion of the interfacing edge82of the second threaded portion16extends into the pilot hole30when the threaded connection is made up (e.g.,FIG. 4A. To that end, in some embodiments, pilot hole30may be formed through the first threaded portion14such that a center point84of the pilot hole30is a shorter distance away from the interfacing edge80than the diameter of the pilot30. In some embodiments, the pilot hole30may be a partially drilled hole for receiving the anti-rotation device18. That is, the pilot hole30may be drilled to a diameter that is less than the diameter of the corresponding anti-rotation device18to be installed therethrough. For example, the partially drilled hole may be drilled to a diameter that is within a range of approximately 1% to 99%, 10% to 90%, 40% to 85%, or 70% to 80% of the diameter of the anti-rotation device18. That way, when the anti-rotation device18is installed into the threaded connection via the pilot hole30, the anti-rotation device18may engage and deform a portion of both the first and second threaded portions14and16along the full length of the anti-rotation device18. This may provide a solid connection between the anti-rotation device18and both threaded portions14and16, thereby preventing rotation of the threaded portions14and16relative to one another.

Although only one anti-rotation device18is illustrated inFIGS. 3B and 4B, it should be noted that in other embodiments any desirable number of anti-rotation devices18may be positioned within the connector assembly12to prevent further rotation of the threaded portions14and16. The number of anti-rotation devices18used to secure the connector assembly12may be determined based on the materials used for the first and second threaded portions14and16.

FIG. 5illustrates a method90for securely coupling two tubular components using the presently disclosed anti-rotation device18and connector assembly12. The method90may include pre-drilling (block92) the pilot hole30and any desired counterbores54through the first threaded portion14of the connector assembly12. The holes30and/or counterbores54may be formed at different points around the outer diameter of the first threaded portion14.

In some embodiments (e.g.,FIGS. 1A-2C), the first threaded portion14may include a groove20formed therein, and the pilot hole30may be pre-drilled (block92) through an outer ring50of the first threaded portion14on the external side of the groove20. In some embodiments, additional counterbores56may be pre-drilled into the internal body52of the first threaded portion14on the other side of the groove20. In still other embodiments (e.g.,FIGS. 3A-4B), the pilot hole30may be pre-drilled (block92) through an interfacing edge80of the first threaded portion14.

The method90may then include connecting (block94) the first threaded portion14with the second threaded portion16of the connector assembly12to connect two tubular components at a desired make-up torque. In some embodiments, this may involve connecting the threaded portions14and16such that a groove20formed into the first threaded portion14receives a tab22extending from the second threaded portion16. In other embodiments, an interfacing edge82of the second threaded portion16may extend at least partially into the pre-drilled pilot hole30through the first threaded portion14when the first and second threaded portions14and16are connected.

Once the connector assembly12is made up, the installation tool70may be aligned (block96) with the pilot hole30(e.g., via a corresponding counterbore54). The method90may then include installing (block98) the anti-rotation device18via the installation tool70. In some embodiments, this installation step may include guiding the anti-rotation device18through the first threaded portion14and the tab22via the pilot hole30, as shown inFIG. 2C. In other embodiments, this installation step may include guiding the anti-rotation device18through the first threaded portion14and into engagement with the interfacing edge82of the second threaded portion16along the length of the anti-rotation device18, as shown inFIG. 3B.

In some embodiments, the installation tool70may be a triggered mechanism that utilizes pneumatic pressure, hydraulic pressure, mechanical force, or an explosive charge to force the anti-rotation device18through the connector assembly12. In such instances, this installation may include rifling the anti-rotation device18as it exits the installation tool70to create an interference pattern (i.e., friction fit) that makes the anti-rotation device harder to remove from the connector assembly12. In other embodiments, the installation tool70may be a hammer used to drive the anti-rotation device18(e.g., a tapered pin) into connection with the first and second threaded portions14and16. Thus, the installation step may include hammering the tapered pin into the connector assembly12via the installation tool70.

At this point in the method90, the installation process including aligning (block96) the installation tool70and installing (block98) the anti-rotation device18via the installation tool70may be repeated at different points along the outer circumference of the connector assembly12. This may provide a relatively secure and zero-clearance connection between the two tubular components using the disclosed anti-rotation device18and connector assembly12.