Servicing a top drive device of a wellbore drilling installation

Abstract

A method for servicing a top drive device of a wellbore drilling installation. The installation comprises a drilling tower, a drill floor having a well center through which a drilling tubulars string can pass along a firing line. A trolley is guided along a vertical trolley rail. A top drive device is attached to the trolley and comprises one or more top drive. A motion arm assembly comprises a base and an extensible and retractable motion arm, wherein the base is guided by a vertical motion arm rail. The motion arm has an operative reach that encompasses the firing line. The motion arm assembly is adapted to support at least one of a well center tool, e.g. an iron roughneck tool and a tubular gripper member, and allowing to bring said well center tool or tubular gripper member in the firing line. In order to remove a top drive motor from the top drive device whilst the rest of the top drive device remains attached to the trolley, the motion arm assembly and/or the trolley are operated so that the top drive motor is within the operative reach of the motion arm, the motion arm is operated to reach the top drive motor and the top drive motor is connected to the motion arm, and then the motion arm is used to support and/or lift, lower said top drive motor upon disconnection thereof from the rest of the top drive device.

Claims

1. A method for servicing a top drive device of a wellbore drilling installation, wherein the installation comprises: a drilling tower; a drill floor having a well center for a drilling tubulars string passing through the well center along a firing line; at least one vertical trolley rail; a trolley, said trolley being guided along said at least one vertical trolley rail; a top drive device attached to the trolley, said top drive device comprising one or more top drive motors, adapted to impart rotary motion to a drilling tubulars string when connected to said top drive device; a hoisting device adapted to move the trolley with the top drive device up and down along said at least one vertical trolley rail; a vertical motion arm rail; a motion arm assembly comprising a base and an extensible and retractable motion arm, wherein the base is guided by said at least one vertical motion arm rail, and wherein the motion arm has an operative reach that encompasses the firing line, said motion arm assembly being adapted to support at least one of a well center tool or a tubular gripper member, and allowing to bring said well center tool or tubular gripper member in the firing line; and a motion arm assembly vertical drive which is adapted to move the motion arm base along said at least one vertical motion arm rail, wherein the method comprises removing one of the one or more top drive motors from the top drive device whilst the rest of the top drive device remains attached to the trolley, and wherein the removing comprises: operating the motion arm assembly and/or the trolley so that the one top drive motor is within the operative reach of the motion arm; operating the motion arm to reach the one top drive motor; connecting the one top drive motor to the motion arm; and supporting, lifting or lowering the one top drive motor using the motion arm upon disconnection of the one top drive motor from the rest of the top drive device.

2. The method according to claim 1, wherein the one top drive motor is fitted, permanently or only temporarily during servicing, with a mechanical coupler part that is mated with a corresponding mechanical coupler part that is fitted on the motion arm such that the one top drive motor becomes fixed to the motion arm and fully and directly follows any motion of the motion arm.

3. The method according to claim 2, wherein the well center tool, and/or the tubular gripper member which is/are to be handled by the motion arm that is used in the removal of the one top drive motor is/are provided with a mechanical coupler part similar to a mechanical coupler part of the one top drive motor.

4. The method according to claim 1, wherein the motion arm that is to be used in said removal of the one top drive motor during said servicing is, during a wellbore drilling process, positioned along the at least one vertical motion arm rail in a position near the drill floor to support an iron roughneck tool above the well center, and wherein, before removing the one top drive motor, the trolley is lowered towards the drill floor so that the one top drive motor is within operative reach of said motion arm, and then said motion arm, with the iron roughneck tool detached from the motion arm, is connected to the one top drive motor and supports, lifts or lowers said one top drive motor in the course of its removal from the rest of the top drive device.

5. The method according to claim 1, wherein the motion arm assembly is a first motion arm assembly among a plurality of motion arm assemblies, wherein the motion arm rail is one of a left-hand vertical motion arm rail and a right-hand vertical motion arm rail present on opposed lateral sides of a vertical path of travel of the trolley with the one top drive device along said at least one vertical trolley rail, wherein each motion arm assembly is mounted on one of the left-hand vertical motion arm rail and the right-hand vertical motion arm rail and is vertically mobile along the respective motion arm rail by a respective motion arm assembly vertical drive, and wherein, if a motion arm assembly among the plurality of motion arm assemblies on a first side is used to remove the one top drive motor, a motion arm assembly among the plurality of motion arm assemblies on a second side is used to stabilize the one top drive device and/or the trolley, the second side being different than the first side.

6. The method according to claim 1, wherein the motion arm assembly is a first motion arm assembly among a plurality of motion arm assemblies, wherein the motion arm rail is one of a left-hand vertical motion arm rail and a right-hand vertical motion arm rail present on opposed lateral sides of a vertical path of travel of the trolley with the one top drive device along said at least one vertical trolley rail, wherein each motion arm assembly is mounted on one of the left-hand vertical motion arm rail and the right-hand vertical motion arm rail and is vertically mobile along the respective motion arm rail by a respective motion arm assembly vertical drive, wherein the one or more top drive motors are provided on respective left-hand and right-hand lateral sides of the top drive device, and wherein a left-hand motion arm assembly among a plurality of motion arm assemblies is used to remove a left-hand side top drive motor among the one or more top drive motors and a right-hand side motion arm assembly among a plurality of motion arm assemblies is used to remove a right-hand side top drive motor among the one or more top drive motors.

7. The method according to claim 1, wherein a spare top drive motor is stored in a compartment within the operative reach of the motion arm assembly, said spare top drive motor being provided with a mechanical coupler part that is to be mated with a corresponding mechanical coupler part on the motion arm to cause the fixation of the spare top drive motor to the motion arm, and wherein the motion arm is used to move the spare top drive motor out of the compartment and then bring it to the top drive device, the spare top drive motor being fitted to the top drive device as a replacement of a faulty top drive motor among the one or more top drive motors.

8. The method according to claim 1, wherein at least one tubulars storage rack stores multi-joint tubulars therein in vertical orientation, and wherein the motion arm assembly is a first motion arm assembly among a plurality of motion arm assemblies, each motion arm assembly comprising a base and an extensible and retractable motion arm, each motion arm assembly being arranged on respective vertical motion arm rail along a side of a vertical path of travel of the trolley with the top drive device along said at least one vertical trolley rail, at least two of said motion arms being provided with a tubular gripper member, with said motion arm rail extending over such a height that a multi-joint tubular stored in the at least one tubulars storage rack can be gripped by the gripper members of the respective motion arm assemblies which act in unison as part of a tubular racker device.

9. A wellbore drilling installation with a top drive device, wherein the installation comprises: a drilling tower; a drill floor having a well center for a drilling tubulars string passing through the well center along a firing line; at least one vertical trolley rail; a trolley, said trolley being guided along said at least one vertical trolley rail; a top drive device attached to the trolley, said top drive device comprising one or more top drive motors, the top drive device being adapted to impart rotary motion to a drilling tubulars string when connected to said top drive device; a hoisting device adapted to move the trolley with the top drive device up and down along said at least one vertical trolley rail; a vertical motion arm rail; a motion arm assembly comprising a base and an extensible and retractable motion arm, wherein the base is guided by said at least one vertical motion arm rail, and wherein the motion arm has an operative reach that encompasses the firing line, said motion arm assembly being adapted to support at least one of a well center tool or a tubular gripper member, and allowing to bring said well center tool and/or tubular gripper member in the firing line; a motion arm assembly vertical drive which is adapted to move the motion arm base along said at least one vertical motion arm rail; and a mechanical coupler part that is fitted on the motion arm, wherein each of the one or more top drive motors is fitted, permanently or only temporarily during servicing, with a mechanical coupler part that is adapted to be mated with the mechanical coupler part that is fitted on the motion arm such that the one or more top drive motors becomes fixed to the motion arm and fully and directly follows any motion of the motion arm.

10. The wellbore drilling installation according to claim 9, wherein the well center tool and/or the tubular gripper member is/are provided with a mechanical coupler part that is similar to a mechanical coupler part of the one or more top drive motors allowing the coupling thereof to the mechanical coupler part that is fitted on the motion arm.

11. The wellbore drilling installation according to claim 9, wherein the vertical motion arm rail is one of a left-hand vertical motion arm rail and a right-hand vertical motion arm rail present on opposed lateral sides of a vertical path of travel of the trolley with the top drive device, wherein the motion arm assembly is a first motion arm assembly among a plurality of motion arm assemblies, and wherein each motion arm assembly is mounted on one of the left-hand vertical motion arm rail and the right-hand vertical motion arm rail and is vertically mobile along the respective rail by a respective motion arm assembly vertical drive.

12. The wellbore drilling installation according to claim 9, wherein the vertical motion arm rail is one of a left-hand vertical motion arm rail and a right-hand vertical motion arm rail present on opposed lateral sides of a vertical path of travel of the trolley with the top drive device along said at least one vertical trolley rail, wherein the motion arm assembly is a first motion arm assembly among a plurality of motion arm assemblies, wherein each motion arm assembly is mounted on one of the left-hand vertical motion arm rail and the right-hand vertical motion arm rail and is vertically mobile along the respective rail by a respective motion arm assembly vertical drive, wherein the top drive device has at least one top drive motor among the one or more top drive motors on the respective left-hand and right-hand lateral sides thereof, and wherein the motion arm assembly mounted on the left-hand vertical motion arm rail is adapted to be used to remove a left-hand side top drive motor and the motion arm assembly mounted on the right-hand vertical motion arm rail is adapted to be used to remove a right-hand side top drive motor.

13. The wellbore drilling installation according to claim 9, wherein the installation comprises a spare top drive motor and a spare top drive motor storage compartment within the operative reach the motion arm assembly, said spare motor being provided with the mechanical coupler part that is to be mated with the mechanical coupler part on the motion arm to cause the fixation of the spare top drive motor to the motion arm.

14. In combination a wellbore drilling trolley and top drive device, which comprises: a trolley, said trolley being adapted to be guided along at least one vertical trolley rail; and a top drive device attached to the trolley, said top drive device includes: one or more top drive motors; a gearbox or transmission housing; and a rotary stem or a quill driven by said one or more top drive motors, wherein said top drive device is adapted to impart rotary motion to a drilling tubulars string when connected to the stem or the quill of the top drive device, wherein the trolley comprises a frame with a top frame member that is adapted to be suspended from one or more winch driven cables of a hoisting device, wherein the frame supports, below said top drive device, a rotatable head clamp assembly that is provided with an open-centered rotary body with a vertical passage there-through that allows lowering of the rotatable head clamp assembly from above onto a top end of a tubular in the firing line, wherein the rotatable head clamp assembly is provided with a tool joint retainer assembly to axially retain a tool joint at the top end of the tubular while the tool joint remains accessible for the rotary stem or the quill of the top drive device, said tool joint having a shoulder and said rotatable head clamp assembly having one or more retainers that are engageable underneath said shoulder, and wherein the rotatable head clamp assembly is provided with a thrust bearing adapted to support the load of a drilling tubular string during a drilling process, when the quill or the rotary stem of top drive device is connected to the tool joint of the top end of the drilling tubular string.

15. The combination of claim 14, wherein the trolley comprises a loop shaped frame with: said top frame member; a lower frame member, spaced below the top frame member and a first and second frame members connecting the lower frame member to the top frame member, wherein the top drive device is arranged generally within the opening in the loop shaped frame, and wherein the lower frame member supports said rotatable head clamp assembly.

16. The combination of claim 14, wherein the rotatable head clamp assembly and the thrust bearing is embodied as an exchangeable unit.

17. The combination of claim 14, wherein the top drive device is mounted within the frame so as to be vertically mobile relative to the frame by one or more vertical displacement actuators, and wherein said one or more vertical displacement actuators are adapted to perform a controlled lowering and raising of the top drive device during a make-up or a breaking of the threaded connection between the quill or the rotary stem and to suspend the tool joint of the tubular from the rotatable head clamp assembly.

18. The combination of claim 17, wherein a flexible first drilling fluid hose suspended from an elevated position and hanging in an open loop is connectable at an end thereof to a rigid pipe piece that is fitted on the trolley, and wherein a shorter, flexible second drilling fluid hose is connected between said rigid pipe piece and the vertically mobile top drive device.

19. The combination of claim 14, wherein one or more vertical actuators are provided that allow to vertically displace at least the rotary stem or the quill relative to the rotatable head clamp assembly, and wherein said one or more vertical actuators are adapted to perform a controlled lowering and raising of the rotary stem or quill during a make-up or a breaking of a threaded connection between the quill or the rotary stem and to suspend the tool joint of the tubular from the rotatable head clamp assembly.

20. A method for drilling a wellbore, comprising the step of using the trolley and top drive device combination according to claim 14.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a wellbore drilling installation with a top drive device according to the invention,

(2) FIG. 2A shows in side view the trolley and top drive device of the installation of FIG. 1,

(3) FIG. 2B shows in view from the rear the trolley and top drive device of the installation of FIG. 1,

(4) FIG. 3A illustrates a motion arm assembly of the installation of FIG. 1 provided with a tubular gripper member,

(5) FIG. 3B illustrates the cooperation of the mechanical coupler parts of the motion arm and the tubular gripper member of FIG. 3A,

(6) FIG. 3c schematically shows an electric top drive motor provided with a mechanical coupler part adapted to be coupled to a mechanical coupler part on the motion arm,

(7) FIG. 4 illustrates from above the drilling tower, trolley, and motion arm assemblies of the installation of FIG. 1,

(8) FIG. 5 shows the trolley and top drive device of the installation of FIG. 1 in perspective view,

(9) FIG. 6 illustrates an example of the rotatable head clamp assembly,

(10) FIGS. 7a-c further illustrate the rotatable head clamp assembly of FIG. 6,

(11) FIG. 8 shows an alternative embodiment of the trolley and top drive device of the installation of FIG. 1 in perspective view.

DETAILED DESCRIPTION OF EMBODIMENTS

(12) FIG. 1 shows a wellbore drilling installation with a top drive device according to the invention. It is envisaged that the depicted installation is part of an offshore drilling vessel for performing offshore drilling and/or other wellbore related activities, e.g. well intervention.

(13) As will be clear from the following description FIG. 1 only shows the trolley with the top drive device removed for reasons of clarity. Other figures do show the ensemble of the trolley and the top drive device.

(14) The installation comprises a drilling tower 1 that is here embodied as a mast with a closed contoured steel structure with at least one firing line outside of the mast itself. For example the mast is arranged adjacent a moonpool of a drilling vessel, or over a larger moonpool with two firing lines along opposed outer faces of the mast 1 as is known in the art.

(15) In an alternative design the drilling tower is embodied as a derrick with the firing line within the structure of derrick, e.g. the derrick having a lattice structure placed over the moonpool.

(16) FIG. 1 shows a drill floor 2 having a well center 3, e.g. with a slip device arranged at said location, through which a drilling tubulars string 4, 8 can pass along a firing line 5.

(17) The mast 1 is at the side of the drill floor 2 provided with two parallel vertical trolley rails 6, 7. A trolley 10 is guided along the trolley rails 6, 7.

(18) A top drive device 30 is attached to the trolley 10.

(19) The top drive device 30 comprises in this example two electric top drive motors 31, 32 which commonly drive, via gearbox or transmission in housing 33, a rotary stem or quill 34. As known in the art the quill 34 is connectable, e.g. via a threaded connection, e.g. via a saver sub, to the top end of a drilling tubular aligned with the firing line. Thereby the top drive device 30 is able to impart rotary motion and drive torque to a drilling tubulars string.

(20) A hoisting device 50 is provided that is adapted to move the trolley with the top drive device up and down along the vertical trolley rails 6,7.

(21) A left-hand motion arm rail 60 and a right-hand motion arm rail 61 are present on opposed lateral sides of a vertical path of travel of the trolley 10 with the top drive device 30 along said the vertical trolley rails 6,7.

(22) On each of said motion arm rails 60, 61 at least one, here three as is preferred, motion arm assembly 70, 71, 72, 80, 81, 82 is arranged. Each assembly is, as preferred independently controlled from any other assembly on the same rail 60, 61, vertically mobile along the respective rail by a respective motion arm assembly vertical drive.

(23) FIG. 3A illustrates a possible embodiment of a motion arm assembly 70, with, as is preferred, the other assemblies 71, 72, 80, 81, 82 of the same design.

(24) The assembly 70 is the lowermost assembly on rail 60. The assembly 70 comprises a base 74 that is mounted mobile on the rails 60.

(25) The assembly further comprises an extensible and retractable motion arm 75, here a telescopic arm with a first arm section 75a connected to the base 74, and one or more, here two, telescopic second and third arm sections 75b, 75c. For example the arm sections are extensible by associated hydraulic cylinders of the arm 75. The motion arm has an operative reach that encompasses the firing line so that the arm can handle drilling tubulars and/or well center equipment, or other tooling that needs to be presented or held in the firing line.

(26) As is preferred the arm 75, here the first arm section 75a, is connected to the base 74 via a slew bearing 76 allowing to rotate the arm about a vertical axis by means of an associated slew drive.

(27) The assembly 70 further comprises a motion arm assembly vertical drive, here with one or more motors 78 each driving a pinion meshing with a rack that extends along the rail 60. Thereby the base can move along the at least one vertical motion arm rail and the drive with motors 78 is sufficiently strong to do so while the motion arm assembly carries a load in the firing line of at least 1000 kg, preferably at least 5000 kg.

(28) At the end of the motion arm 75, here at the end of third section 75c, a mechanical coupler part 79 is provided.

(29) By means of the coupler part the motion arm assembly 70, here each of the depicted motion arm assemblies, is able to support at least one of a well center tool, e.g. an iron roughneck tool 85, or a tubular gripper member 90, and allowing to bring said well center tool or tubular gripper member in the firing line.

(30) For this reason each of said tubular gripper members 90 and/or the iron roughneck tool 85 is provided with a mechanical coupler part 91 (see FIG. 3B) that is adapted to be mated with the mechanical coupler part 79 that is fitted on the motion arm 75 such that the respective gripper member, iron roughneck tool, or other well center tool, becomes fixed to the respective motion arm and fully and directly follows any motion of the motion arm.

(31) As illustrated in FIGS. 2A, 2B, and 3C it is envisaged that each top drive motor 31, 32 is also provided, e.g. permanently or only temporarily during servicing, with a mechanical coupler part 37, 38 that is adapted to be mated with the mechanical coupler part 79 that is fitted on the motion arm 75 of assembly 70 such that the motor can be fixed to the motion arm and fully and directly follows any motion of the motion arm.

(32) The motion arm is designed carry the weight of the top drive motor 31, 32 as the motor is disconnected from the rest of the top drive device 30 and, preferably, also to transport said motor vertically by means of the drive with one or more motors 76.

(33) As depicted it is envisaged that the coupler parts 79, 37, 38 allow to connect the motor 31, 32 to the arm 75 by means of a vertical relative motion, e.g. with one or more hook portions of the coupler part 79 engaging from beneath under corresponding lifting bosses or a lifting pin on the motor 31, 32. It will be appreciated that other mechanical coupler arrangements are also possible to obtain the desired direct mechanical coupling between the motor and the arm 75.

(34) In a less preferred embodiment there is no direct mechanical fixation of the top drive motor 31, 32 to a respective motion arm and instead a rope sling or other similar flexible member is used to suspend the motor from the motion arm. This suspension from the arm by a flexible element, e.g. a cable, however does not allow to make full use of the motion control and stability of the motion arm for positioning of the motor, which is in particular disadvantageous in offshore applications where vessel motion may become problematic.

(35) It is envisaged that the top drive motors 31, 32 are mounted in the top drive device to be arranged on the respective left-hand and right-hand lateral sides thereof, allowing one or more of the left-hand motion arm assemblies 70, 71, 72 to be used to remove a left-hand side top drive motor 31 and one or more of the right-hand side motion arm assemblies 80, 81, 82 to be used to remove a right-hand side top drive motor 32.

(36) It is envisaged that, e.g. in case of a failure of one of the top drive motors 31, 32 and/or the need to gain access to the gearbox or transmission housing by removal of a motor, a motion arm assembly, e.g. a lowermost assembly 70, 80, is used in the process of removal of the top drive motor from the top drive device whilst the rest of the top drive device remains attached to the trolley 10.

(37) In this removal process, for example, the trolley 10 is lowered so that it is closely above the drill floor 2. Then the motion arm assembly 70, with any well center tool and/or tubular gripper member removed therefrom, is operated so that the top drive motor 31 is within the operative reach of the motion arm 70. Then the motion arm 75 is extended to reach the top drive motor 31 and the top drive motor 31 is connected to the motion arm 75 by mating coupler part 79 with the respective coupler part 37 of the drive motor 31. Then the motion arm 75 is used to support and/or lift, lower this top drive motor 31 upon disconnection thereof from the rest of the top drive device. For example the arm retains the motor 31 whilst the trolley and/or the rest of the top drive device are lifted to clear the motor 31 from the rest of the device 30.

(38) In an embodiment it is envisaged that, if the motion arm assembly on one side is used to couple with and remove a top drive motor, a motion arm assembly on the other side is used to stabilize the top drive device and/or the trolley. For example this other motion arm assembly couples to the top drive motor on the other side of the top drive device, which motor is not to be removed, and/or onto the housing of the gearbox/transmission, and/or onto a part of the trolley or frame thereof. For example the frame of the trolley is equally provided with one or more mechanical coupler parts that can be mechanically fixed to a mechanical coupler part on a motion arm of one or more of the assemblies 70, 71, 72, 80, 81, 82.

(39) It is envisaged, in an embodiment that the installation comprises a spare top drive motor and a spare top drive motor storage compartment within the operative reach of a motion arm assembly, e.g. a lowermost assembly on one of the rails 60, 61. Preferably this spare motor is provided, either permanently or temporarily, with a mechanical coupler part that is to be mated with the mechanical coupler part 79 on the motion arm to cause the fixation of the spare top drive motor to the respective motion arm. Preferably the motion arm is adapted to be used to move the spare top drive motor out of the compartment and then bring it to the top drive device, where the spare top drive motor can be fitted to the top drive device as a replacement of a faulty top drive motor.

(40) As depicted there are two one tubulars storage racks 110, 120, each along a respective side of the mast 10. These racks 110, 120 are each adapted to store multi-joint tubulars, here triples 8 (about 36 meter), therein in vertical orientation.

(41) It is illustrated that two of the motion arm assemblies 71, 72, 81, 82 on each vertical rail 60, 61 are equipped with a tubular gripper 85. The height of the rails 60, 62 is at least such that the upper assembly 72, 82 can be arranged to grip the tubular in the storage rack 110, 120 at an appropriately high location.

(42) The assemblies with grippers 85 can be operated in unison to act as part of the tubular racker device allowing to transfer drilling tubulars, e.g. drill pipe or casing pipe or other drilling tubulars between the firing line and the respective storage rack 110, 120.

(43) The trolley 10 is provided with a rigid frame 150 that supports the top drive device 30.

(44) Generally in the depicted preferred embodiment the frame 150 forms a rigid loop in a central vertical plane through the firing line 5 and perpendicular to the adjacent side of the mast and/or the plane through the rails 60, 61.

(45) The frame 150 has a top frame member 151 that is suspended from one or more winch driven cables of the hoisting device 50. Here, as preferred, the top frame member 151 carries multiple travelling sheaves 51 in a side-by-side arrangement, with the sheaves 51 having a common, horizontal, axis of rotation. The one or more hoisting cables 52 extend between these travelling sheaves 51 and sheaves 53 of the crown block 54, from which the one or more cables 52 pass to one or more winches (not shown). As is preferred a heave compensation mechanism is provided that acts on the one or more cables 52 to afford heave compensation of the trolley 10 and the attached top drive device 30.

(46) The frame comprises a lower frame member 152, spaced below the top frame member 151, that is rigidly connected via a front frame member 153 and a rear frame member 154 to the top frame member 151.

(47) The lower frame member 152 extends perpendicular to the axis of rotation of the multiple sheaves 51 on the top frame member. This embodiment is e.g. advantageous in combination with a top drive device wherein two vertical axis electrical top drive motors 31, 32 are arranged underneath a gearbox or transmission housing 33, e.g. a left-hand motor and a right-hand motor as shown.

(48) The housing 33 is guided along the frame members 153, 154, e.g. by guide rails thereon, e.g. also absorbing reaction torque of the drive motors 31, 32.

(49) As is preferred these motors 31, 32 are in vertical projection on opposed sides of the lower frame member 152. The removal of these motors 31, 32 in the manner described herein, or in another manner, is facilitated as the motors 31, 32 can, once detached from the housing 33, easily be lowered relative to the gearbox or transmission housing. It will be appreciated that said lowering can be performed by raising the trolley and/or lowering the respective motion arm assembly.

(50) The lower frame member 152, e.g. embodied with two parallel lower frame girders, supports a rotatable head clamp assembly 140 that is provided with an open-centered body 141 with a vertical passage there through that allows to lower the head clamp assembly 140 from above over the top end of a tubular 8 in the firing line 5, e.g. positioned in the firing line by a racker device with gripper members 90 during drilling operations or the top end of the tubular string suspended from a drill floor mounted slip device.

(51) The rotatable head clamp assembly is provided with a tool joint retainer assembly, e.g. with retainers engaging underneath a shoulder of the tool joint or box member of the tubular, that is embodied to axially retain the tool joint or box member at the top of the tubular whilst the tool joint or box remains accessible for the quill 34 or rotary stem of the top drive device 30.

(52) As is preferred the rotatable head clamp assembly is provided with a thrust bearing 142 adapted to support the load of the drilling tubular string 4 during a drilling process, when the quill 34 or rotary stem of top drive device is connected to the tool joint or box member of the top end of the drilling string, e.g. by a threaded connection, e.g. using a saver sub. This arrangement allows to dispense with the thrust bearing in the top drive device itself, and mount said thrust bearing in or on the lower frame member of the frame. The rotatable head clamp assembly can thus rotatably support an entire tubular string and allow for rotary motion thereof which is imparted by the rotary stem or quill of the top drive device.

(53) The provision of the rotatable head clamp assembly 140 with thrust bearing 142 separated from the structure of the top drive with transmission and one or more top drive motors 31, 32 allows for reduced complexity of the top drive device 30 compared to existing devices wherein the thrust bearing is within the housing of the device 30 and very difficult to access and exchange.

(54) The rotatable head clamp assembly 140 including the thrust bearing 142 preferably is embodied as an exchangeable unit, e.g. with a housing wherein the thrust bearing and the open-centered body of the assembly are mounted and wherein said housing is placed in a receptor of the lower frame member 152. For example the receptor is an open topped cavity in the lower frame member.

(55) For example the rotatable head clamp assembly 140 is designed to handle a firing line load of at least 1000 tonnes.

(56) Reference numeral 190 indicates a wrench device that allows to retain the tool joint or box member held by the assembly 140 when make-up or break-up of a threaded connection is performed.

(57) The top drive device 30 is mounted within the frame 150 so as to be vertically mobile relative to the frame by one or more vertical displacement actuators 39, e.g. adapted to perform controlled lowering and raising of the top drive device during make up or breaking of the threaded connection between the quill 34 or rotary stem on the one hand and the tool joint or box member of the tubular suspended from the rotatable head clamp assembly 140 on the other hand.

(58) With reference to FIGS. 6, 7a c, now an embodiment of the rotatable head clamp 140 will be discussed in more detail.

(59) The head clamp 140 here comprises: a rotary open-centered body 141 defining a vertical passage 141a in line with firing line 5 to allow passage of a pipe or tubular of a drill string in firing line 5, e.g. a special sub fitted to the top end of the drill string or drill pipe to be added to the drill string and having at a top end thereof a tool joint or box member similar to tubulars making up the drill string; a thrust bearing 143 supporting the rotary body 141, allowing rotation thereof under the full load of the drilling tubulars string hanging along the firing line 5 in the wellbore; for example the thrust bearing has a load rating of 1000 tonnes or more; multiple mobile retainers 142 supported by the rotary body 141 so as to provide an operative and a non-operative mode of the rotatable head clamp 140.

(60) In the shown embodiment, the rotatable head clamp 140 comprises a housing 149 supporting the thrust bearing 143, which housing is supported by the lower frame member 152. Alternatively, the lower frame member 152 supports the head clamp 140 directly via the thrust bearing 143. Either way, the lower frame member 152 absorbs the load of the suspended drill string, which is then transmitted via the frame members 153, 154 directly to the top frame member 151. The top frame member 151 is suspended from a hoisting device, e.g. a winch and cable hoisting device, here with travelling sheaves 51 attached to said top frame member 151. The vertical load or weight of the drill string suspended in the firing line 5 from the head clamp 140, and thus supported by the thrust bearing 143, does not pass through the top drive device 30, allowing for a simple and more lightweight structure of the top drive device 30, e.g. of the gearbox or transmission housing thereof.

(61) Here, the rotary body 141 is embodied as a cylinder 141b with a flanged top end 141a supporting the mobile pipe retainers 142. The thrust bearing 143 supports the flanged top end 41a of the rotary body.

(62) Furthermore, in the shown embodiment and as preferred, an additional radial load bearing 144 is provided at the bottom end of the rotary body 141. A bearing connection 149a, which is a static frame part optionally integrated with housing 149, connects the thrust bearing 143 at the upper side of the rotary open-centered body with bearing 144 at the bottom end thereof.

(63) In the shown embodiment, the lower frame member furthermore supports a centralizer, with one or more centralizer members 210, which is arranged below the head clamp 140 to centralize the drill string. Such centralizers are known in the art.

(64) The mobile retainers 142 are movable between a non-operative position and an operative position. In the non-operative position (not shown) the retainers 142 allow passage of a pipe of the drill string, e.g. a special sub fitted to the drill string, through the passage 141a. In the operative position as shown in FIG. 4, the retainers 142 engage below a shoulder 8b of the tool joint or box portion 8a of a pipe or tubular, e.g. special sub, of the drill string 8 extending through the passage 141a so as to suspend said drill string therefrom.

(65) In the shown embodiment, the mobile retainers 142 each have a jaw 142a to engage on a drilling tubular near or at the shoulder of the tool joint, which is preferably an exchangeable jaw to be able to match the diameter and/or shape to the type of pipe.

(66) In FIGS. 7a-c a possible embodiment of a head clamp is shown in top view, a perspective top view and a side view. This head clamp is provided with two sets each three mobile pipe retainers 142 and 142 respectively. Each set is adapted to retain a different type of pipe. This is advantageous as it is possible to have one set in the non-operative position and the other in the operative position.

(67) The mobile retainers 142, 142 of FIG. 6 and FIG. 7a-c are, by way of example, embodied as a pivotal lever comprising an arm and a fulcrum, which fulcrum 142c is fixed to the rotary body 141, here on a flange 141a thereof. One end 142a of the arm is adapted to in the operative position engage on the pipe or tubular. Here, this end 142a of the arm is provided with clamping jaws 142d. In the non-operative position has cleared the area in line with the pipe passage to allow the passage of a pipe of the drill string. The other end 142b of the arm is operable by an actuator 146 to move the opposite end of the arm between the operative and the non-operative position. Here, the actuator 146 is embodied as a hydraulically operable finger engaging on the arm end 142b.

(68) A flexible first drilling fluid hose 170 is suspended from an elevated position on the tower 10 and hangs in a loop and is connected at the other end to a rigid pipe piece 171 that is fitted on the trolley. A further, much shorter, flexible second drilling fluid hose 172 is connected between said rigid pipe piece 171 and the vertically mobile top drive device 30, e.g. to the fluid swivel 36a thereof. It will be appreciated that the latter fluid hose 172 can be rather short. The same arrangement can be provided for any hydraulic and/or electric lines that are to be connected to the top drive device. In this manner the vertically mobile top drive device is not subjected to the weight of the long first drilling fluid hose and other lines, which weight may be substantial if the drilling installation is e.g. embodied to handle triples or quads.

(69) It is illustrated that the top drive device comprises a gearbox or transmission housing 33 and two or more vertical axis electric motors 31, 32 mounted to this housing, here one motor at each lateral side of the top drive device 30. The one or more vertical axis electric motors 31, 32 are arranged underneath the gearbox or transmission housing 33, e.g. each on a lateral side of the top drive device, with the rotary stem or quill 34 extending downward from the gearbox or transmission housing 33 in a space between said downward depending top drive motors 31, 32. This arrangement may allow for a reduction of the height of the top drive device 30 and/or of the related frame 150.

(70) The trolley is connected, here as permanently welded structure, to the rear frame member 154.

(71) In an embodiment it is envisaged that a motion arm assembly is employed to couple with a removable rotatable head clamp assembly 140, e.g. one or more rope slings being fitted between the motion arm assembly 140 and the rotatable head clamp assembly. In another embodiment it is envisaged that a mechanical coupler part is temporarily secured to the removable head clamp assembly 140 allowing for direct mechanical connection to a mating coupler part 79 on the motion arm.

(72) Preferably the top drive device 30 can be raised by means of actuators 39 relative to the rotatable head clamp assembly 140 over such a height that the head clamp assembly 140 can be lifted out of an open topped receptor cavity in or on the lower frame member.

(73) The frame 150 and hoisting device 50 preferably have sufficient strength and capacity to also handle a weight of a subsea riser string when appropriate. For example a riser lifting tool can be attached to the lower frame member 152 of the frame, e.g. the lower frame member 152 having connection stubs 156 at opposed side thereof from which a riser lifting tool can be suspended.

(74) For example the frame 150 and hoisting device 50 have sufficient strength and capacity to handle a load of 1000 tonnes or more in the firing line.

(75) FIG. 8 depicts an alternative trolley 310, in particular an alternative frame.

(76) The trolley 310 is provided with a rigid frame 350 that supports the top drive device 30. Generally, in the depicted embodiment, the frame 350 forms a rigid loop in a central vertical plane through the firing line 5 and perpendicular to the adjacent side of the mast and/or the plane through the rails 60, 61.

(77) The frame 350 has a top frame member 351 that is suspended from one or more winch driven cables of the hoisting device 50. Here, as preferred, the top frame member 351 carries multiple travelling sheaves 51 in a side-by-side arrangement, e.g. with the sheaves 51 having a common, horizontal, axis of rotation. The one or more hoisting cables extend between these travelling sheaves 51 and sheaves of the crown block, from which the one or more cables pass to one or more winches (not shown). As is preferred a heave compensation mechanism is provided that acts on the one or more cables to afford heave compensation of the trolley 310 and the attached top drive device 30.

(78) The frame here comprises a releasable lower frame member or rotatable head clamp carrier 352, that is spaced below the top frame member 351.

(79) The lower frame member or rotatable head clamp carrier 352 is connected via frame member 353 and frame member 354 to the top frame member 351, so that the vertical load absorbed by the thrust bearing in the rotatable head clamp is passed directly via said frame members 353, 354 to the top frame member and does not pass through the top drive device 30.

(80) As schematically shown it is provided for that the carrier 352 can be released from the lower end of the members 353, 354 in order to move the carrier, and the rotatable head clamp 140, away from underneath the top drive device 30.

(81) The carrier 352 here extends perpendicular to the axis of rotation of the multiple sheaves 51 on the top frame member. This embodiment is e.g. advantageous in combination with a top drive device wherein two vertical axis electrical top drive motors 331 are arranged underneath a gearbox or transmission housing 333, e.g. a left-hand motor and a right-hand motor as shown. Another arrangement, e.g. with the carrier parallel to the top frame member 151 is also envisaged. In said embodiment the frame members 353, 354 will be embodied as left-hand and right-hand frame members of the frame.

(82) The housing 333 of the top drive device 30 is guided along one or more of the vertical frame members 353, 354, e.g. by guide rails thereon, e.g. also absorbing reaction torque of the one or more drive motors 331.

(83) Here these motors 331, 332 are in vertical projection on opposed sides of the lower frame member 352.

(84) The top drive device 30 is mounted within the frame 350 so as to be vertically mobile relative to the frame by one or more vertical displacement actuators 39, e.g. adapted to perform controlled lowering and raising of the top drive device during make up or breaking of the threaded connection between the quill 334 or rotary stem on the one hand and the tool joint or box member of the tubular suspended from the rotatable head clamp assembly 140 on the other hand.

(85) The frame of the trolley and hoisting device 50 preferably have sufficient strength and capacity to also handle a weight of a subsea riser string when appropriate. For example a riser lifting tool can be attached to the vertical frame members 18, 19; 353, 354, e.g. after removal of the carrier 19, 352 and then attached to said vertical frame members.

(86) It will be appreciated in general, that with the carrier 19, 352 removed other components may become suspended from the first and second vertical frame members of the trolley frame.

(87) It will also be appreciated that, if desired, a common elevator device may be attached to the frame, e.g. to the carrier 19, 352, e.g. for handling tubulars that are to be supplied by a catwalk machine.