DRILL AHEAD ROTATING CONTROL DEVICE METHODOLOGY AND SYSTEM

A technique facilitates deployment and use of a seal rotating system without retrieving the running tool prior to a drilling operation. The running tool remains with the drill string after deployment of the seal rotating system which saves substantial time by avoiding retrieval of the running tool prior to conducting the drilling operation. According to an embodiment, a seal rotating system is mounted to the running tool and the running tool is connected into a drill string. The running tool is used to position the seal rotating system in a rotating control device housing which may be positioned along, for example, a riser. The running tool is then released from the seal rotating system and is moved downhole as part of the drill string to enable performance of a borehole drilling operation without removing the running tool.

BACKGROUND

In many oil and gas well applications, a rotating control device is used to contain and isolate pressure in the wellbore annulus while rotary drilling. The rotating control device comprises a housing and an inner seal rotating system. When used in offshore operations, e.g. subsea drilling, the rotating control device housing may be integral to a riser system extending up through the sea toward a surface facility from a seabed location. The seal rotating system is deployed inside the rotating control device housing and at least portions of the system rotate with the drill string during a drilling operation while maintaining a seal between the drill string and the rotating control device housing. A running tool is used to carry the seal rotating system down through, for example, the riser, until deployed into the rotating control device housing. However, the running tool is then pulled back to the surface and removed before the drill string can be run back in hole so that drilling can begin.

SUMMARY

In general, a methodology and system facilitate deployment and use of a seal rotating system without retrieving the running tool prior to a drilling operation. The running tool remains with the drill string after deployment of the seal rotating system, thus saving substantial time by avoiding retrieval of the running tool prior to conducting the drilling operation. According to an embodiment, a seal rotating system is mounted to the running tool and the running tool is connected into a drill string. The running tool is used to position the seal rotating system in a rotating control device housing which may be positioned along, for example, a riser. The running tool is then released from the seal rotating system and is moved downhole as part of the drill string to enable performance of a borehole drilling operation without removing the running tool.

DETAILED DESCRIPTION

The disclosure herein generally involves a methodology and system which generally facilitate the drilling of a borehole, e.g. a wellbore. In forming various hydrocarbon, e.g. oil and/or gas, wells a rotating control device is used to contain and isolate pressure in the wellbore annulus while rotary drilling. The rotating control device comprises a housing and an inner seal rotating system. In this example, the methodology and system described below facilitate deployment and use of the seal rotating system without retrieving the running tool prior to a drilling operation. The running tool remains with the drill string after deployment of the seal rotating system. This approach saves substantial time by avoiding retrieval of the running tool prior to conducting the drilling operation.

When used in deepwater operations, for example, a traditional running tool may take up to24hours to deploy. In some deepwater applications, the methodology described below may reduce that time by a factor of four or more. The rig operation time savings translates directly to cost savings.

According to an embodiment, a seal rotating system is mounted to a running tool and the running tool is connected into a drill string. The running tool is used to position the seal rotating system in a rotating control device housing. In deepwater applications, the rotating control device housing may be positioned along a riser. The running tool is then released from the seal rotating system and is moved downhole as part of the drill string to enable performance of a borehole drilling operation without removing the running tool.

Referring generally toFIG.1, a system20for containing and isolating pressure in a borehole annulus, e.g. a wellbore annulus, while rotary drilling is illustrated. In this example, the system20comprises a rotating control device22having a rotating control device housing24forming an internal longitudinal passage26. In a variety of subsea applications or other deepwater applications, the rotating control device housing24may be positioned along a riser28extending between, for example, a seabed location and a surface facility. However, the rotating control device housing24may be positioned along other types of equipment for use in other types of drilling applications.

In the illustrated example, the rotating control device22also comprises a seal rotating system30. The seal rotating system30is constructed for movement down into the rotating control device housing24via passage26where it is held in a desired position along passage26via fastening mechanisms32. In some embodiments, the fastening mechanisms32may be remotely controllable from a surface location. For example, the fastening mechanisms32may be hydraulically or electrically controlled and may comprise pistons, threaded members, or other suitable mechanisms which may be moved into passage26so as to secure the seal rotating system30at the desired location along passage26.

With additional reference toFIG.2, the seal rotating system30may comprise a stationary housing structure34which is secured with respect to the rotating control device housing24via fastening mechanisms32. The seal rotating system30also comprises a dynamic or rotating portion36which is allowed to rotate with a drill string38via a bearing assembly40. The bearing assembly40is mounted between the stationary housing structure34and a dynamic housing structure42of dynamic portion36. The dynamic housing structure42is able to freely rotate with respect to the stationary structure34via bearing assembly40.

The dynamic housing structure42may be constructed in a variety of configurations with a variety of features and components. For example, the dynamic housing structure42may comprise suitable types of couplers44by which at least one seal46, e.g. an elastomeric seal, is connected to the dynamic housing structure42. In the embodiment illustrated, a plurality of seals46, e.g. two elastomeric seals46, may be used and positioned, for example, above and below bearing assembly40. Each of the seals46is constructed with an opening48sized to receive the drill string38therethrough while remaining in sealing engagement with the drill string38. The bearing assembly40allows the seals46and the dynamic housing structure42to rotate with the drill string38.

Referring also toFIG.3, the seal rotating system30may be deployed and lowered into the rotating control device housing24via a running tool50. For example, once the bearing assembly40of the seal rotating system30is in the rotating control device housing24, a pull test may be performed to confirm the position of the seal rotating system30within the rotating control device housing24. The running tool50comprises connection ends52which allow the running tool50to be coupled into drill string38and to become a part of drill string38. For example, the connection ends52may be in the form of box and pin connection ends such as those used to connect joints of drill pipe when assembling various types of drill strings38.

As the drill string38is made up on a rig, for example, the seal rotating system30may be mounted on the running tool50by sliding the running tool50through the interior of the seal rotating system30. Additionally, the seal rotating system30is releasably secured to the running tool50. The running tool50may then be connected into the drill string38. Subsequently, additional joints of drill string38may be connected above the running tool50as the running tool50and attached seal rotating system30are moved downwardly. It should be noted the illustrated running tool50has an internal passageway53through which fluid may be flowed. For example, drilling mud may be flowed down through the drill string38and thus through passageway53. The mud flow returns may be routed through, for example, a side outlet located below the rotating control device housing24.

In the embodiment illustrated, the stationary housing structure34comprises a mounting portion54having an opening56sized to slide along the running tool50until the mounting portion54comes to rest on a shoulder58formed along an expanded portion60of running tool50. Once the seal rotating system30is resting on shoulder58, a releasable mounting system62is used to temporarily affix the seal rotating system30on shoulder58of running tool50. This allows the running tool50to be used for securely deploying the seal rotating system30down, e.g. down through riser28, until the seal rotating system30is moved into passage26and secured via fastening mechanisms32.

At this stage, the releasable mounting system62enables release of running tool50from seal rotating system30so that the running tool50may be moved downhole as part of drill string38to perform a desired drilling operation, e.g. a wellbore drilling operation. By way of example, the releasable mounting system62may comprise a shear member64, e.g. a plurality of shear members64. In the embodiment illustrated, the plurality of shear members64take the form of shear bolts66positioned to temporarily secure mounting portion54of seal rotating system30to running tool50. Various other types of releasable mounting systems62may be used to enable controlled release of the running tool50from seal rotating system30so as to enable the desired drilling operation without retrieving the running tool50to the surface.

When the desired drilling operation is completed or otherwise interrupted, the drill string38may be pulled to the surface. As the running tool50is moved upwardly with the drill string38, the shoulder58once again engages the seal rotating system30(via mounting portion54) as it moves into the rotating control device housing24. The fastening mechanisms32are then released to allow the seal rotating system30to be lifted from the rotating control device housing24. In this manner, the seal rotating system30is automatically lifted to the surface with the running tool50as the drill string38is retrieved.

Referring generally toFIGS.4and5, an embodiment of running tool50is illustrated. In this example, running tool50is formed as an elongate body68having a mandrel70extending between connection ends52. By way of example, the connection ends52may be in the form of pin and box connection ends having threaded regions72positioned for threaded engagement with the consecutive pipe joints of drill string38.

The expanded portion60is a larger diameter section located along the mandrel70. According to one or more embodiments of the present disclosure, the larger diameter section of the expanded portion60may be set up like a stabilizer with carbide bricks and fluting to allow passing of cuttings and reduce wear on the diameter of the section. As illustrated, the expanded portion60defines shoulder58which is oriented to catch and block further downward travel of seal rotating system30as described above.

When releasable mounting system62comprises shear bolts66, the elongate body68may be formed with threaded openings74oriented laterally to threadably receive corresponding threaded shear bolts66. By way of example, the threaded openings74may be positioned circumferentially about the expanded portion60on an uphole side of shoulder58. The threaded shear bolts66may be inserted through lateral openings76of mounting portion54(seeFIGS.6and7) and threaded into openings74so as to temporarily secure the seal rotating system30on running tool50.

In this example, the number of threaded openings74is greater than the number of shear bolts66/lateral openings76to facilitate rotational alignment of the seal rotating system30when securing it to running tool50. By way of example, the number of threaded openings74may be three times greater than the number of shear bolts66(e.g. 18 threaded openings74and six shear bolts66). This allows the seal rotating system30to be secured to the running tool50at a variety of different rotational angles. In some embodiments, the threaded openings74may be formed in bushings78which are releasably coupled with elongate body68.

By way of example, the bushings78may have external threads and may be threadably engaged with corresponding threaded openings80formed in elongate body68. In this manner, the running tool50is protected from damage when the shear bolts66are sheared to release the seal rotating system30as the running tool50is moved downhole with the drill string38to perform the desired drilling operation, e.g. wellbore drilling operation. If the shearing action damages the internal threads of bushings78, the bushings78may simply be removed from elongate body68and replaced with new bushings78. The use of bushings78also enables easy changing of the diameter of threaded openings74by simply swapping in different bushings78. This allows the use of different size shear bolts66so as to change the shear force needed to release the running total50from the seal rotating system30.

Referring again toFIGS.6and7, an embodiment of releasable mounting system62is illustrated in which shear bolts66are threadably engaged with bushings78. Bushings78may be releasably secured in elongate body68at, for example, expanded portion60. In this embodiment, the lateral openings76extend from a recessed portion82formed in mounting portion54.

As illustrated, each of the shear bolts66may have a bolt head84which is retained in the recessed portion82after shearing of the shear bolts66. Furthermore, each of the bolt heads84may be retained by a cap86, e.g. a threaded cap, secured in or at the recessed portion82so as to trap the bolt head84and prevent it from falling downhole after shearing. The other end of each shear bolt66is retained via its threaded engagement with the corresponding bushing78.

The system utilizing shear bolts66provides an example of releasable mounting system62which enables secure attachment of the seal rotating system30to the running tool50until the seal rotating system30is properly secured in rotating control device housing24. Then, sufficient weight/force may be applied to the drill string38so as to shear the shear bolts66, thus releasing the running tool50from the seal rotating system30. The running tool50may then be moved downhole with the drill string38to facilitate performance of the desired drilling operation.

According to a deepwater operational example, the running tool50is stabbed into the bottom of the seal rotating system30at the surface rig and then lifted until the shoulder58rests against the bottom of the seal rotating system30(against mounting portion54). Then, multiple shear bolts66are threaded into openings74in selected, corresponding bushings78so as to secure the seal rotating system30to the running tool50. The running tool50and the seal rotating system30may then be lifted and torqued into the drill string38followed by deployment of the running tool50and seal rotating system30down the riser28and into the rotating control device housing24.

When the seal rotating system30is properly inside the rotating control device housing24, it is landed and latched in place via fastening mechanisms32. At this point, the weight of the drill string38may be used to shear the shear bolts66and to release the running tool50from the seal rotating system30so the running tool50and the drill string38may be moved down through the interior of seal rotating system30. Thus, the drill string38, including running tool50, is free to continue ahead for performance of the desired drilling operation.

After the drilling operation is completed or otherwise stopped, the drill string38may be retrieved to the surface along with the running tool50. The shoulder58of running tool50engages with the seal rotating system30as the running tool50is pulled upwardly through the rotating control device housing24. The seal rotating system30is unlatched from the rotating control device housing24by releasing fastening mechanisms32and then lifted back to the surface via shoulder58as the drill string38is pulled to the surface.

Depending on the specific well operation and well equipment, the overall system20may be adjusted and various additional or alternate components may be utilized. For example, the features, size, and shape of the seal rotating system30and running tool50may be adjusted. Additionally, the components may be constructed for use in a variety of subsea applications and also other types of drilling applications.