APPARATUS AND METHOD FOR REPLACING CABLE OR WIRE IN A HOISTING SYSTEM

Abstract

A method for replacing a length of a wire/cable in a hoisting system. The wire/cable extends from a storage drum to a winch. The method includes removing at least one lock which prevents a deadline anchor arranged between the storage drum and the winch from rotating, reeling onto the storage drum a first length of the wire/cable with a simultaneous coordinated operation of the deadline anchor and the storage drum, the simultaneous coordinated operation being controlled so that the wire/cable is in a continuous tension between the deadline anchor and the storage drum, securing the wire/cable to an attachment point, cutting a section of the wire/cable between the attachment point and the winch and removing the cut section of the wire/cable, reattaching the wire/cable remaining to the winch, reeling out a second length of the wire/cable from the storage drum, and securing the wire/cable to the deadline anchor.

Claims

1-9. (canceled)

10. A method for replacing a length of a wire or cable in a hoisting system, the wire or cable extending from a storage drum at a first end to a winch at a second end, the method comprising: removing at least one lock which prevents a deadline anchor arranged between the storage drum and the winch from rotating; reeling onto the storage drum a first length of the wire or cable with a simultaneous coordinated operation of the deadline anchor and the storage drum, the simultaneous coordinated operation being controlled so that the wire or cable is in a continuous tension between the deadline anchor and the storage drum; securing the wire or cable to an attachment point; cutting a section of the wire or cable between the attachment point and the winch and removing the cut section of the wire or cable; reattaching the wire or cable remaining to the winch; reeling out a second length of the wire or cable from the storage drum; and securing the wire or cable to the deadline anchor.

11. The method as recited in claim 10, wherein the second length corresponds to at least one of a length of the section of wire or cable which was cut and removed and to a length of the wire or cable which is temporarily stored on the storage drum.

12. The method as recited in claim 10, wherein the removing of the at least one lock which prevents the deadline anchor arranged between the storage drum and the winch from rotating further comprises: adjusting a hydraulic operation of the storage drum so that the wire or cable is held substantially tensioned between the deadline anchor and storage drum.

13. The method as recited in claim 10, wherein the reeling out of the first length of the wire or cable from the storage drum further comprises: adjusting a hydraulic operation of the storage drum so that the wire or cable is held substantially tensioned from the storage drum.

14. The method as recited in claim 10, wherein the step of cutting the section of the wire or cable between the attachment point and the winch and removing the cut section of the wire or cable further comprises: reeling off the wire or cable remaining from the winch.

15. An arrangement for a winch, the arrangement comprising: a storage drum and a deadline anchor arranged on a deadline side of a hoisting system; a winch arranged on a fastline side of the hoisting system; and a wire or cable arranged to extend, via the hoisting system, from the winch to the storage drum via the deadline anchor, wherein, the storage drum comprises a motorized drive configured to reel in and to reel out the wire or cable from the storage drum, and the deadline anchor comprises a motorized drive configured to enable a rotation of the deadline anchor in a first rotation direction and in a second rotation direction so as to provide a coordinated operation with the reeling in and the reeling out of the wire or cable on the storage drum.

16. The arrangement as recited in claim 15, further comprising: a common hydraulic system; and a control device; wherein, the storage drum and the deadline anchor are each connected to the common hydraulic system, and the common hydraulic system is connected to the control device.

17. The arrangement as recited in claim 15, wherein each of the storage drum and the deadline anchor comprise at least one of a hydraulic motor and a hydraulic brake.

18. The arrangement as recited in claim 15, wherein the deadline anchor comprises a drum, a base, and a locking device which is configured to lock the drum in relation to the base.

19. The arrangement as recited in claim 18, wherein the deadline anchor further comprises a guide device configured to guide the wire or cable when the wire or cable is reeled onto the deadline anchor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention is described in greater detail below on the basis of embodiments and of the drawings in which:

[0014] FIG. 1 shows a schematic diagram of a drilling tower with a hoisting system according to the present invention;

[0015] FIG. 2 shows steps in a “cut and slip” procedure according to the present invention including where the locking pins (not shown) locking the drum of the deadline anchor to the deadline anchor foundation are removed, and where weight is then taken off the wire or cable by a hang off wire supporting the weight of the travelling block and holding the travelling block in a predetermined position in the derrick;

[0016] FIG. 3 shows steps in a “cut and slip” procedure according to the present invention including where the wire or cable is temporary fastened to the derrick by an attachment point provided at a distance from the winch, and where the wire or cable is then cut below the attachment point;

[0017] FIG. 4 shows steps in a “cut and slip” procedure according to the present invention including where the remaining length of the wire or cable on the winch is reeled off and disposed of;

[0018] FIG. 5 shows steps in a “cut and slip” procedure according to the present invention including where the free end of the wire or cable is moved to the winch and is installed in the wire or cable lock (not shown) in the drum of the winch;

[0019] FIG. 6 shows steps in a “cut and slip” procedure according to the present invention including where the winch is used to reel on wire or cable from the storage drum and to the winch drum;

[0020] FIG. 7 shows steps in a “cut and slip” procedure according to the present invention including where a length of wire or cable is reeled off from the storage drum;

[0021] FIG. 8 shows an arrangement for a winch according to the present invention; and

[0022] FIG. 9 shows details of a hydraulic system according to the present invention.

DETAILED DESCRIPTION

[0023] The present invention relates to a method and to an apparatus for the replacement of a wire or cable of a hosting system. The described method and apparatus are applicable both to upgrade existing hoisting systems and for new hoisting systems which are installed on a drilling installation (platform) offshore or onshore.

[0024] A “cut and slip” procedure according to the present invention may typically include at least some of the following steps: [0025] Releasing load from a wire or cable by hanging off a traveling block and a drilling machine in a dedicated relief wire, which is mounted in a derrick, so that the wire or cable is not subjected to a load other than its own weight. [0026] Dismantling locking bolts from a deadline anchor, which prevent the deadline anchor from rotating, and then releasing the wire or cable from the deadline anchor wire or cable lock. [0027] Using a drive on the deadline anchor to reel the wire or cable off a winch drum and onto a storage drum. The drive of the storage drum is adjusted to keep the wire or cable between the deadline anchor and storage drum substantially tensioned. One person can thereby operate both the drive on the deadline anchor and the driving of the storage drum. [0028] Reeling the wire or cable back onto the storage drum until a minimum number of turns of wire or cable is left on the winch drum. Approximately 60 m of wire or cable can, for example, be reeled back onto the storage drum whereupon approximately 5 turns will usually be left on the winch drum, which is equivalent to approximately 30 m. [0029] Securing the wire or the cable to the derrick and preparing to cut. The free end of the wire or cable after the cut must be long enough to allow installation in a wire or cable lock arranged on the winch drum. [0030] Reeling off and disposing of the remaining “old” wire or cable left on the winch drum. [0031] Installing the free end of the wire or cable in the winch drum wire or cable lock. [0032] Reeling the wire or cable onto the winch drum from the storage drum via the deadline anchor. This will correspond to about 5 turns, as well as the length of wire or cable required to lower the drilling machine and traveling block down to the drill floor from the point of suspension, which is normally about 90 m. The adjusting of the hydraulic pressure on the storage drum motor provides that the wire or cable is kept tensioned during the operation. [0033] Locking the wire or cable to the deadline anchor with one or more locking clamps. The deadline anchor is locked by installing the locking bolts. [0034] Releasing the travelling block and drilling machine from the hang off wire.

[0035] The hoisting system is operative.

[0036] The present invention also relates to an arrangement for a winch, the arrangement comprising a storage drum and a deadline anchor where the storage drum and the deadline anchor are arranged on a deadline side of an hoisting system and wherein a winch is further provided on a fastline side of the hoisting system, where a wire or cable, via the hoisting system, extends from the winch and to the storage drum, via the deadline anchor, where the storage drum comprises a drive for reeling wire or cable on or off the storage drum, while the deadline anchor comprises a drive allowing rotation of the deadline anchor in both rotational directions for a coordinated operation with the reeling on or off the storage drum.

[0037] In an embodiment of the present invention, the storage drum can, for example, include a motorized drive to reel on and to reel off the wire or cable from the storage drum, while the deadline anchor may include a motorized drive allowing rotation of the deadline anchor in both rotational directions (clockwise and counter-clockwise) so as to provide a coordinated operation with reeling and unreeling of wire or cable from the storage drum.

[0038] In an embodiment of the present invention, the motorized drive for the drum and the deadline anchor can, for example, be connected to a common hydraulic system which may further be connected to a common control device.

[0039] The motorized drive for the storage drum and/or the deadline anchor can, for example, be one or more hydraulic motors, hydraulic brakes, or the like.

[0040] In an embodiment of the present invention, the deadline anchor can, for example comprise a drum, a base, and one or more locking devices.

[0041] The present invention provides a method of replacing at least parts of a wireline or cable length of a hoisting system, such as a drill line, where the wire or cable extends from a storage reel at one end and to a winch in the other end, comprising the steps of: [0042] a) suspending a traveling block (7) in a predetermined position in a derrick (1) and removing locks which prevent a deadline anchor (3) from rotating; [0043] b) reeling onto the storage drum (2) a first length of wire or cable (5) with the simultaneous coordinated operation of the deadline anchor (3) and storage drum (2), where the operation is controlled so that the wire or cable (5) is in continuous tension between the deadline anchor (3) and the storage drum (2); [0044] c) securing an end of the wire or cable (5) to an attachment point (9) in the derrick (1) in preparation for cutting the wire or cable (5) in a section of the wire or cable between the attachment point (9) and the winch (4); [0045] d) cutting the wire or cable (5) and discarding the cut wire or cable (5); [0046] e) attaching the remaining wire or cable (5) to the winch (4); [0047] f) reeling out a length wire or cable (5) from the storage drum (2), the length corresponding to the length of discarded wire or cable (5) and the length of temporarily stored wire on the storage drum (2); and [0048] g) securing the wire or cable (5) to the deadline anchor (3).

[0049] In an embodiment of the present invention, the method comprises in step b) an additional step of adjusting the hydraulic operation of the storage drum so that the wire or cable is held substantially tensioned between the deadline anchor and storage drum.

[0050] In an embodiment of the present invention, the method comprises in step f) a further step of adjusting the hydraulic operation of the storage drum so that the wire or cable is held substantially tensioned from the storage drum.

[0051] In an embodiment of the present invention, the method comprises in step d) a further step of reeling off remaining wire or cable from the winch.

[0052] A non-limiting embodiment of the present invention will now be described below under reference to the accompanying drawings wherein like items are given like reference numerals.

[0053] FIG. 1 shows a schematic view of a land or offshore based drilling rig (not shown), where drilling rig comprises a derrick 1 with a hoisting system and an arrangement for a winch, where the derrick 1 is used for lifting and lowering of pipes and other equipment in a well. The hoisting system includes a storage drum 2 and a deadline anchor 3, wherein the storage drum 2 and the deadline anchor 3 are arranged on a deadline side of the hoisting system. A winch 4, comprising a drum, is further arranged on a fastline side of the hoisting system. A wire or cable 5 extends from the winch 4 and over at least one sheave 6 in the derrick 1, via a traveling block 7, further over at least one sheave 6 in the derrick 1 and further via the deadline anchor 3 and to the storage drum 2, so as to provide a connection between the deadline side and the fastline side of the hoisting system.

[0054] During normal use of the hoisting system, the deadline anchor 3 will be locked to prevent it from rotating, and the winch 4 is used for lifting and/or lowering pipes and/or other equipment in the well. Locking the deadline anchor 3 may, for example, be done by using locking bolts (not shown) etc., where the locking bolts then lock the drum 31 of the deadline anchor 3 to the deadline anchor foundation 32.

[0055] When the wire or cable has been in use for a number of ton-miles in a hoisting system as described above, a certain length of the wire or cable 5 is “replaced”, due to wear and/or bending of the wire or cable 5, whereby the replacement is performed via a so-called “cut and slip” procedure. Such wear or bending of the wire or cable 5 most often occurs near the sheaves 6, in the crown block, and the traveling block 7, and when entering the drum of the winch 4 etc.

[0056] A method for replacing at least a section of a wire or cable 5 in a hoisting system according to the present invention will now be described in relation to FIGS. 2-7.

[0057] In FIG. 2, the locking pins (not shown) locking the drum 31 of the deadline anchor 3 to the deadline anchor foundation 32 are removed. Weight is then taken off the wire or cable 5 by a hang off wire 8, supporting the weight of the travelling block 7 and holding the traveling block 7 in a predetermined position in the derrick 1. Since the deadline anchor 3 and storage drum 2 are connected to each other through a hydraulic drive system, which will be explained further in relation to FIG. 9, one person will be able to operate both storage drum 2 and deadline anchor 3 simultaneously. By the use of hydraulic drives on both storage drum 2 and the deadline anchor 3, the wire or cable 5 can be reeled off the winch 4 and onto the storage drum 2. The hydraulic operation of the storage drum 2 can be adjusted to maintain some tension in the wire or cable 5 between the deadline anchor 3 and storage drum 2.

[0058] Wire or cable 5 will be reeled from the winch 4 to the storage drum 2 until a minimum number of turns of wire or cable 5 is left on the drum of the winch 4. The length of reeled wire or cable 5 onto the storage drum 2 will be approximately 60 m, while approximately 30 m will be left on the drum of the winch 4.

[0059] FIG. 3 shows that, when the above specified length of the wire or cable 5 is reeled on to the storage drum 2 and there is about 30 m of wire or cable 5 remaining on the drum 31 of the winch 4, the wire or cable 5 will be temporary fastened to the derrick 1 by an attachment point 9, whereby the attachment point 9 is provided at a distance from the winch 4. The wire or cable 5 will subsequently be cut below the attachment point 9. The cutting of the wire or cable 5 is carried out so that a free end of the wire or cable 5, after cutting, is sufficiently long to allow the wire or cable 5 to be mounted in a wireline or cable lock (not shown) in the drum of the winch 4.

[0060] FIG. 4 shows that the remaining length of the wire or cable 5 on the winch 4 is reeled off and disposed of in an appropriate manner.

[0061] FIG. 5 shows that the free end of the wire or cable 5 is moved to the winch 4 and installed in the wire or cable lock (not shown) in the drum of the winch 4.

[0062] FIG. 6 shows that the winch 4 is used to reel on wire or cable 5 from the storage drum 2 and to the winch drum. A length of wire or cable 5 equivalent to approximately 5 turns of wire or cable 5 on the winch drum and a length of wire or cable 5 that is needed to lower the traveling block 7 from the suspension point and down to the drill floor B is reeled onto the winch 4. This length is approximately 90 m. The wire or cable 5 is held in continuous tension from the storage drum 2 by adjusting the hydraulic drive of the storage drum 2 and the deadline anchor 3. This provides that the wire or cable 5 will be reeled correctly over the sheaves 6, the traveling block 7, and the drum of the winch 4.

[0063] FIG. 7 shows that the correct length of wire or cable 5 is reeled off from the storage drum 2. The deadline anchor 3 will again be locked by the locking bolts (not shown) locking the drum 31 of the deadline anchor 3 to the base 32 of the deadline anchor 3. Finally, the hang off wire 8 will be removed from the traveling block 7. The hoisting system is then again operational, but with the strained sections of the wire or cable 5 having been moved to less loaded sections of the drill line 5.

[0064] FIG. 8 shows an arrangement related to the hoisting system of the present invention where, in connection with the deadline anchor 3, a storage drum 2 is also used, whereby the deadline anchor 3 and the storage drum 2 are connected by a hydraulic system 12 (see FIG. 9) connected to a control device 10. The deadline anchor 3 and the storage drum 2 are each equipped with a plurality of hydraulic motors (not shown) which allow the deadline anchor 3 and storage drum 2 to rotate in both directions (clockwise and counter-clockwise). One operator (not shown) can thereby use the control device 10 to control reeling, unreeling, the force which the storage drum 2 applies to the wire or cable 5, etc. in order to obtain a correct installation of the wire or cable 5.

[0065] Storage drum 2 comprises a tire 21 and a base 22. The deadline anchor 3 comprises a drum 31 and a base 32, where the drum 31 and the base 32 are designed so that the drum 31 can be locked to the base 32 when the hoisting system is operational (in normal operation).

[0066] FIG. 9 shows the hydraulic system 12 which controls the deadline anchor 3 and the storage drum 2. Hydraulics are supplied from a hydraulic pump unit (not shown) which normally has a working pressure of approximately 210 bar. The power to a hydraulic motor A, which controls the deadline anchor 3, and a hydraulic motor D, which controls storage drum 2, is regulated by pressure control valves C and F, where the pressure control valve C regulates the pressure to the hydraulic motor A for the deadline anchor 3 and pressure control valve F regulates the pressure to the hydraulic motor D for the storage drum 2, respectively. The hydraulic flow is further led to a 4-way valve B and E, where the 4-way valve B is used for the deadline anchor 3 and the 4-way valve E for storage drum 2, which both regulate the direction of rotation of hydraulic motors A, D and the speed of hydraulic motors A, D. By controlling the power, speed and rotation direction of the hydraulic motors A, D, an approximately constant tension on the wire or cable 5 between the storage drum 2 and the deadline anchor 3 during reeling operations can be maintained. The deadline anchor 3 acts as a winch in these operations. Because there are only three turns of wire or cable 5 on the deadline anchor drum 31, the wire or cable 5 may be displaced continuously laterally, one wire or cable thickness, by guide devices (not shown) which push the wire or cable 5 laterally on the drum 31 of deadline anchor 3, and thereby provide space for new wire or cable 5 which is reeled on. The tensioning of the wire or cable 5 between the storage drum 2 and the deadline anchor 3 for this reason must not be too high, so that lateral displacement of the wire or cable 5 is achieved.

[0067] The embodiments described herein are intended for illustrative purposes and are not be deemed to be in any way limiting. A person skilled in the art can make modifications or alterations to the invention without departing from the scope of the present invention as defined in the appended claims. The individual steps of the procedure may, for example, in some cases be performed in a different order than other steps. It is also understood that the specified lengths of wire or cable that is spooled on or off the storage drum and/or the winch may vary, depending on the hoisting system lifting height, the drum diameter of the storage drum and/or winch drum, the number of sheaves and lines and/or the traveling block and drilling machine size etc. Reference should also be had to the appended claims.

[0068] What is claimed is: