GB2581227A

GB2581227A - Drilling plant and method of operation

Info

Publication number: GB2581227A
Application number: GB1915116.6A
Authority: GB
Inventors: Olav Holen Bernt
Original assignee: Mhwirth AS
Current assignee: Mhwirth AS
Priority date: 2018-10-22
Filing date: 2019-10-18
Publication date: 2020-08-12
Anticipated expiration: 2039-10-18
Also published as: NO20181350A1; GB201915116D0; NO345583B1; GB2581227B

Abstract

A power tong machine 20 has a frame 21, a power tong unit 25, and a backup tong unit 24. There may also be present a drilling plant having a power tong machine 20 and a drilling machine 10 with a shaft 13 and at least one tubular element 14-17 threadedly connected to the shaft 13; and a method for operating a drilling plant comprising the steps bringing first and second subs 14-17 into engagement with the power tong unit 25, operating the power tong unit 25 to break out a threaded connection between the first sub and the second sub, and operate the drilling machine 10 to spin out the threaded connection between the first sub and the second sub by rotating the shaft 13.

Description

DRILLING PLANT AND METHOD OF OPERATION

The present invention relates to a drilling plant and a method of operation.

BACKGROUND

In drilling operations, for example in the oil and gas industry, it is common to use a drilling plant with a variety of machines for handling a drill string made up of sections of drill pipe during drilling operations. Such machines may include, among other things, a drilling machine for rotating the drill string, a hoisting system for lifting and lowering the drilling machine and/or the drill string, a roughneck machine having tongs for making up (connecting) or breaking out (disconnecting) sections of drill pipe into or out of the drill string, machines for handling drilling fluids, etc. Such drilling plants are conventionally used both onshore and offshore, including on fixed and floating installations.

Machines such as top drive drilling machines and roughnecks are subject to very high operational demands. In use, they may subjected to very high forces due to the high torques required during drilling and connection/disconnection of sections of drill pipe, and due to the high weight of the drill string. There may also be large load variations during the repeated connect/disconnect sequences when adding or removing sections of pipe to the drill string, and it may also be subject to very high adverse loads such as vibrations or other forces extending upwards through the drill string, for example during jarring events. These machines therefore require periodic inspection and maintenance, for example replacement of worn components.

Documents which may be useful for understanding the background includes US 8,939,048, US 7,861,619 and US 7,931,077 Many operations on a drilling plant are currently carried out manually, which can be time consuming and involves health and safety risks, for example when human operators need to be present on the drill floor. There is therefore a continuous move towards automation, both for higher efficiency and in order to improve personnel safety. The present invention has the objective to provide improved systems and methods in these or other areas, and to obviate or reduce disadvantages associated with known solutions and techniques.

SUMMARY

In an embodiment, there is provided a power tong machine having a frame, a power tong unit, and a backup tong unit.

In an embodiment, there is provided a drilling plant having a power tong machine and a drilling machine, the drilling machine having a shaft and at least one tubular element threadedly connected to the shaft.

In an embodiment, there is provided a method for operating a drilling plant, comprising the steps: bringing a first sub suspended by the drilling machine shaft into engagement with the power tong unit; bringing a second sub suspended by the drilling machine shaft into engagement with the backup tong unit, operating the power tong unit to break out a threaded connection between the first sub and the second sub, and operate the drilling machine to spin out the threaded connection between the first sub and the second sub by rotating the shaft.

Further embodiments are outlined in the detailed description below and in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described on the basis of the drawings in which: Fig. 1 illustrates parts of a drilling plant according to an embodiment. Fig. 2 illustrates parts of a drilling plant according to an embodiment. Fig. 3 illustrates parts of a drilling plant according to an embodiment. Fig. 4 illustrates parts of a drilling plant according to an embodiment.

DETAILED DESCRIPTION

Illustrative embodiments of the present invention will now be described with reference to the figures. The basic design and functionality of conventional top drive systems and roughneck machines is well known in the art and will therefore not be described in detail herein. Reference is made to the above mentioned patent publications.

Fig. 1 shows, schematically, a top drive drilling machine 10 and a power tong machine 20, also known as a roughneck, which are part of a drilling plant. The top drive 10 has a housing 11 with a motor therein. The motor 12 may, for example, be a hydraulic motor or an electric motor. A shaft 13 extends downwards from the motor 12 and out of the lower end of the top drive 10.

Attached to the shaft by threaded connection is an intermediate sub 14, a first internal blow out preventer (IBOP) 15, a second IBOP 16 and a saver sub 17. (It is common to refer to these units 14-17 collectively as "subs", which is then taken to understand also IBOPs 15,16.) The subs 14,17 and IBOPs 15,16 are themselves attached to each other by threaded connections. The saver sub 17 is at its lower end configured for threaded connection to the upper end of a drilling string or a drill pipe section (not shown in Fig. 1). The top drive 10 is suspended by a hoisting system through wires 17 and vertically movable above a well centre opening 31 in a drill floor 30. A fluid conduit 18 is arranged in the top drive 10 to provide a drilling fluid ("mud") through the subs 14,17 and IBOPs 15,16 and for pumping down through the drill string. The drilling fluid is supplied to the top drive 10 from an external source via a pipe (not shown). The person skilled in the art will recognize this arrangement of the top drive 10 as being equivalent to that of conventional top drive systems.

During operation of the drilling plant, the subs 14,17 and IBOPs 15,16 require periodic removal and replacement, as these components will be subject to wear and may have limited permitted operational lifetime for safety reasons.

Conventionally, this is done manually by workers on the drill floor 30. The inventor has discovered that various challenges arise from this, for example that the tendency in the industry to move towards harsher operating areas and to drill longer wells drives higher connection torques on the subs and IBOPs, complicating the work associated with breaking out subs and IBOPs. Further, during manual making up of such subs and IBOPs, it is a challenge to ensure that correct torque is applied, which may reduce component lifetime and/or require more periodic replacement.

Figure 1 further shows a roughneck 20 according to one embodiment. The roughneck 20 has a frame module 21 which is movable on the deck floor 30 by means of wheels 21a,b. The wheels 21a,b may cooperate with guide rails or tracks (not shown) on the drill floor 30. Alternatively, the roughneck 20 may be movable on or above the drill floor 30 by any other motive arrangement. The motive arrangement is arranged so as to move the roughneck 20 between a first, advanced, position in which it is positioned above the well centre opening 31 and a second, retracted, position in which it is spaced from the well centre opening 31. Figure 1 shows the second position.

The roughneck 20 has a power tong 25 and a backup tong 24. The backup tong 24 is arranged below the power tong 25, and both the backup tong 24 and the power tong 25 is supported by the tong module 22 arranged on the frame 21. The power tong 25 and the backup tong 24 operate in the conventional manner (see, for example, the US patent documents cited above), with the backup tong 24 operable to engage a section of a pipe and hold the pipe rotationally fixed in the backup tong 24. The power tong 25 is operable to engage a section of a pipe and rotate the pipe with high torque. The backup tong 24 and the power tong 25 may thus make up or break out a threaded connection between two pipe ends.

Figure 2 shows an embodiment of a roughneck 20 and a top drive 10. Fig. 2 illustrates a situation in which the roughneck 20 is brought to its advanced position above the well centre opening 31 and the top drive 10 is lowered down towards the roughneck 20. In this case, the top drive 10 has two tubular elements: an intermediate sub 14 and a first internal blow out preventer (IBOP) 15 attached to the shaft 13. The top drive 10 is lowered towards the roughneck 20 such that the IPOB 15 is positioned at least partly in the recess 24' of the backup tong 24 and the intermediate sub 14 is positioned at least partly in the recess 25' of the power tong 25. The IBOP 15 can now be broken out of the subs stack by fixing the IBOP 15 by means of the backup tong 24 and engaging and turning the intermediate sub 14 with the power tong 25. When turning the intermediate sub 14, the top drive shaft 13 with turn with it. For this purpose the top drive 10 can be put in an operational position to permit this rotation. Once the high-torque connection between the intermediate sub 14 and the IBOP 15 is loosened, the power tong 25 is disengaged, and the threaded connection is spun out using the top drive 10 motor.

The tong module 22 further has a holding unit 26 configured for receiving and holding one or more of the subs 14-17 when they are broken out. The holding unit 26 may also comprise a lifting unit 27 configured to lift the broken-out sub 14-17 past, or at least towards, the top 23 (see Fig. 1) of the power tong unit 25. This eases access to and handling of the broken-out sub such that it can be removed from the roughneck 20, either manually or by a machine for this purpose. This situation is shown in Fig. 3, which shows a side view of the roughneck 20 shown in Fig. 2. In the situation shown in Fig. 3, the top drive 10 has been moved away from the roughneck 20, and the broken-out sub (in this case the IBOP 15) has been lifted by the lifting unit 27. Access to the broken-out sub is therefore possible from above, and a lifting cap 28 can be attached to the sub for lifting it out of the roughneck 20 and away. Similarly, the lifting unit 27 can be used to lower subs into the tongs 24,25 for make-up purposes.

The lifting unit 27 may, for example, comprise a hydraulic cylinder arranged in the holding unit 26. A pin, a gripping unit, or the like may be provided for engaging the sub and holding it fixed to the lifting unit 27. Alternatively, the sub may simply rest on a top surface of the lifting unit 27 by means of gravity.

The holding unit 26 and/or the lifting unit 27 may be arranged directly and immediately below the recess 25' of the power tong 25 and the recess 24' of the backup tong unit 24 in which the tong jaws operate and which are configured for receiving the subs. Alternatively, the holding unit 26 can be arranged such as to be movable into a position vertically below the recess 24,25', for example by sideways movement within the tong module 22. In the second position, the holding unit 26 intersects a vertical axis 19 (see Fig. 1) extending through the centre of the shaft 13. In this manner, the holding unit 26 can receive the subs 14-17 when broken out, or supply the subs 14-17 directly below the shaft 13 when making up (connecting) the subs 14-17 to the shaft 13.

In the above manner, each of the subs 15-17 can be broken out of the stack and removed. To break out the sub attached directly to the top drive shaft 13, here the intermediate sub 14, the following procedure can be used. The top drive 10 is lowered towards the roughneck 20 such that the intermediate sub 14 is positioned in the power tong 25. A gear lock of the top drive 10 is engaged, such as to prevent any rotation of the shaft 13. Alternatively, another type of rotational lock may be used, such as a shaft brake. The power tong unit 25 is operated to break out the intermediate sub 14 from the shaft 13. The gear lock (or equivalent) is released, and the shaft 13 is spun out from the intermediate sub 14 by operating the top drive 10 to rotate the shaft 13.

The intermediate sub 14 can be supported by the support unit 26 as described above. The lifting unit 27 can be brought in to engagement with the intermediate sub 14 to hold it and/or to lift in towards or above the top surface 23 of the power tong unit 25. A lifting cap 28, or a similar element, can be used to move the intermediate sub 14 away from the roughneck 20, similarly as described above.

In one embodiment, illustrated in Fig. 4, the drilling plant comprises a roughneck having a drill pipe tong module 32 which is configured for making up or braking out sections of drill pipe 36 in the conventional manner. The drill pipe tong module 32 comprises a power tong unit 35 and a backup tong unit 34, equivalently as described above in relation to power tong unit 25 and backup tong unit 24. The drill pipe tong module 32 thus has a through-going central opening extending through the recesses in the power tong unit and backup tong unit so that a drill pipe 36 may extend from the top drive 10, through the drill pipe tong module 32 when this is positioned in its advanced position above the well centre opening 31, and into the wellbore. The drill pipe tong module 32 may also comprise a spinner tong 33 for spinning in or out drill pipe during connection or disconnection.

The drill pipe tong module 32 may be arranged such that, in the second position, no part of the drill pipe tong module 32 intersects the vertical axis 19 (see Fig. 1) extending through the centre of the shaft 13. In this manner, a drill pipe 36 suspended by the top drive 10 may extend through the drill pipe tong module 32 such that a connection (known as a tool joint) can be placed within the power tong unit 35 and backup tong unit 34.

According to this embodiment, when one or more of the subs 14-17 is to be removed from the shaft 13, the tong module 32 may first be removed from the frame module 21. The power tong module 22 for subs removal may then be arranged on the roughneck 20 by arranging it on the frame module 21. The subs 14-17 can then be removed, either individually and one-by-one, several together, or the entire stack. Replacement subs can then be installed in the equivalent manner.

If applicable, any torque wrench or IBOP mechanism can be removed from the top drive 10 prior to breaking out the subs.

According to embodiments described herein, manual operations on the drill floor 30 can be avoided or reduced. Such operations both carries a health and safety risk and is time consuming, which leads to increased cost from non-productive time of the drilling plant. Additionally, or alternatively, by ensuring that correct torque is applied when making up subs 14-17 to the shaft 13, a longer component lifetime is ensured and less frequent replacement is needed while maintaining required safety standards. This can, for example, be achieved by electronic control of the torque applied by the tong modules 24,25 during operation. Alternatively, or additionally, easier access to the subs 14-17 when broken out can be achieved, as well as easier installation of subs 14-17 in that the subs 14-17 can be placed in the tong module 22 on the holding unit 26 before making up.

In the present description, breaking out means applying a torque to two tubular 5 ends connected by a threaded connection, such as to rotate at least one of the ends and loosen the connection. Spinning out means rotating at least one of the ends to thread out the threaded connection, subsequent to breaking out.

In any of the embodiments described herein, the backup tong unit 24 may be 10 arranged below the power tong unit 25.

The invention is not limited to the embodiments described herein: reference should be had to the appended claims.

Claims

CLAIMS 2.A power tong machine (20) having a frame (21), a power tong unit (25), and a backup tong unit (24).
A power tong machine (20) according to claim 1, wherein the power tong unit (25) and the backup tong unit (24) are arranged on a tong module (22) which is removable from the frame (21).
A power tong machine (20) according to the preceding claim, wherein the tong module (22) is a first tong module (22) configured for breaking out subs (14-17) from a shaft (13) of a drilling machine (10), and wherein the power tong machine (20) further comprises a second tong module (32) having a drill pipe power tong unit (35) and a drill pipe backup tong unit (34), the second tong module (32) being removable from the frame (21) and configured for making up or breaking out a threaded connection between two sections of drill pipe (36).
A power tong machine (20) according to any preceding claim, further comprising a support unit (26) configured for holding a tubular element (14-17), the support unit (26) arranged below the power tong unit (25) and the backup tong unit (24).
A power tong machine (20) according to the preceding claim, wherein the support unit (26) comprises a lifting unit (27) configured to lift the tubular element (14-17) towards or past a top surface (23) of the power tong unit (25).
A power tong machine (20) according to any of the two preceding claims, wherein the power tong unit (25) comprises a first recess (25') and the backup tong unit (24) comprises a second recess (24'), the first and second recess (24',25') configured for receiving a tubular element, wherein the support unit (26) is arranged below and aligned with a vertical axis extending through the first and second recess (24,25'), or wherein the support unit (26) is arranged such as to be movable into a position which is aligned with a vertical axis extending through the first and second recess (24,25').
7 A drilling plant having a power tong machine (20) according to any preceding claim and a drilling machine (10), the drilling machine (10) having a shaft (13) and at least one tubular element (14-17) threadedly connected to the shaft (13).
8 A drilling plant according to the preceding claim, wherein the at least one tubular element (14-17) is an intermediate sub (14), an internal blow out preventer (15,16), or a saver sub (17).
9 A drilling plant according to any one of the two preceding claims, further comprising a motive unit (21a,b) arranged for moving the power tong machine (20) between a first position in which the power tong machine (20) is positioned above the well centre opening (31) and a second position in which the power tong machine is spaced horizontally from the well centre opening (31).
10.A drilling plant according to the preceding claim in conjunction with any of claims 4-6, wherein in the second position, the support unit (26) intersects a vertical axis (19) extending through the shaft (13).
11 A method for operating a drilling plant according to any of claims 7-10, comprising the steps: bringing a first sub (14-17) suspended by the drilling machine (10) shaft (13) into engagement with the power tong unit (25), bringing a second sub (14-17) suspended by the drilling machine (10) shaft (13) into engagement with the backup tong unit (24), operating the power tong unit (25) to break out a threaded connection between the first sub and the second sub, and operate the drilling machine (10) to spin out the threaded connection between the first sub and the second sub by rotating the shaft (13).
12.A method according to the preceding claim, further comprising the steps: engaging a lock or a brake in the drilling machine (10), and operating the power tong unit (25) to break out a threaded connection between a first sub (14-17) and the shaft (13).
13.A method according to any of the two preceding claims, further comprising the steps: moving the drilling machine (10) away from the roughneck (20) while supporting a sub with the support unit (26), and removing the sub from the support unit (26).
14.A method according to the preceding claim, further comprising the step: operating a lifting unit (27) to lift the sub towards or past a top surface (23) of the power tong unit (25).
15.A method according to any of the two preceding claims, wherein the step of removing the sub from the support unit (26) comprises attaching a lifting element (28) to the sub.
16.A method according to any of claims 11-15, further comprising the steps: removing from a power tong machine (20) a first tong module (32), the first tong module (32) having a power tong unit (35), a backup tong unit (34), and a through-going, vertical opening configured to receive a drill string, and arranging on the power tong machine (20) a second tong module (22), the second tong module comprising the power tong unit (25) and the backup tong unit (24).
17.A method according to the preceding claim, wherein the first tong module (32) comprises a spinner tong (33).