GB2119749A - Stabbing board arrangement for drilling mast - Google Patents

Stabbing board arrangement for drilling mast Download PDF

Info

Publication number
GB2119749A
GB2119749A GB08230632A GB8230632A GB2119749A GB 2119749 A GB2119749 A GB 2119749A GB 08230632 A GB08230632 A GB 08230632A GB 8230632 A GB8230632 A GB 8230632A GB 2119749 A GB2119749 A GB 2119749A
Authority
GB
United Kingdom
Prior art keywords
carriage
guide track
stabbing board
arrangement
drilling mast
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08230632A
Inventor
Patrick Joseph Persyn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PRE CORP
Original Assignee
PRE CORP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by PRE CORP filed Critical PRE CORP
Publication of GB2119749A publication Critical patent/GB2119749A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21BEARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B15/00Supports for the drilling machine, e.g. derricks or masts
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66FHOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F11/00Lifting devices specially adapted for particular uses not otherwise provided for
    • B66F11/04Lifting devices specially adapted for particular uses not otherwise provided for for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Ladders (AREA)

Abstract

Guide track means (15) is secured in a generally vertical extending relationship with a drilling mast (10), and carries a stabbing board (20) and a ladder, both secured to a carriage (30) for movement with the carriage along the guide track means (15). Motor means (25) and cable means (26, 27) raise and lower the carriage (30) and supported stabbing board (20) along the guide track means (15), and the ladder is connected to the carriage (30) and depends downwardly therefrom for access to the stabbing board (20) from the drilling mast floor. Control means (50) are accessible from the drilling mast floor as well as along the extent of the ladder and guide track means to enable the carriage (30) to be lowered for access to the ladder and stabbing board (20) from the drilling floor and to control the height of the stabbing board from the drilling mast floor. <IMAGE>

Description

SPECIFICATION Stabbing board arrangement for drilling mast In the drilling of wells, such as oil and gas wells, it is necessary to connect successive joints of pipe to form a well string that extends downwardly into a well bore. A joint of pipe to be connected into the well string is lifted vertically in the drilling mast so that the lower end thereof may be aligned with an upwardly extending end of the well string which projects out of the well bore for threadedly engaging therewith. When the pipe joint is properly aligned with the portion of the well string extending downwardly into the well bore, relative rotation between the pipe joint and the well string is effected to threadedly engage them together.During such operation it is desirable to position a man at an elevated position in the drilling mast to assist in the alignment of the pipe joint suspended in the drilling mast with the portion of the well string extending upwardly from the well bore at the floor of the drilling mast which aids in proper connection of the pipe joint into the well string.
Heretofore, various types of arrangements and stabbing boards having been provided on which a man may stand and perform the desired operation of assisting in aligning and guiding the pipe joint as it is suspended within the drilling mast.
Heretofore, in those instances where the stabbing board is either fixed or movable relative to the drilling mast, access to the stabbing board has been gained by climbing a ladder mounted on the mast and then stepping around or through the drilling mast and onto a platform built in the mast. The stabbing board operator then steps off the stationary platform of the drilling mast onto the stabbing board.
The foregoing presents problems and objections in that it requires the casing stabbing board operator to climb the drilling mast ladder and further requires that he thereafter step off onto a platform and then step off the platform built in the drilling mast onto the stabbing board which, in a movable board arrangement, is adjusted (up or down) to an elevation so that access may be gained thereto.
Further, in modern drilling rigs it is desirable that the casing stabbing boards be adjustable from about 23 feet to about 47 feet above the drilling mast floor for handling various length of pipe such as casing.
The present invention provides a casing stabbing board arrangement which enables the casing stabbing board operator to gain access to the casing stabbing board directly from the drilling floor without requiring him to step onto any intermediate platforms as required with the prior art. Also, the casing stabbing board arrangement not only is movable longitudinally within the drilling mast so that it may be positioned at a desired vertical height, but it may be collapsed and readily moved out of position when not in use without increasing the difficulty of getting off the casing stabbing board platform, or gaining access thereto.
An object of the present invention is to eliminate the necessity of an access platform in a drilling mast for gaining access to a stabbing board.
Another object of the present invention is to provide a movable stabbing board arrangement which is constructed and arranged so that access thereto may be attained directly from a drilling floor including guide track means which may be secured in a generally vertically extending relationship on the drilling mast, stabbing board means, carriage means to support the stabbing board for movement along the guide track means, means to raise and lower the carriage means along the guide track means and ladder means connected with the stabbing board means and depending downwardly therefrom for access to the stabbing board means from the drilling mast floor.
Another object of the present invention is to provide a stabbing board arrangement which is constructed and arranged so that access thereto may be attained directly from a drilling mast floor including guide track means which may be secured in a generally vertically extending relationship on the drilling mast, stabbing board means, carriage means to support the stabbing board for movement along the guide track means, means to raise and lower the carriage means along the guide track means, ladder means connected with the stabbing board means and depending downwardly therefrom for access to the stabbing board means from the drilling mast floor and the control means including power control lines extending longitudinally of the guide track means which terminate in spaced relation to the drilling mast floor whereby the power control line means may be manually actuated from the drilling mast floor to lower the carriage means and supported stabbing board means to a position adjacent the drilling mast floor for access to the ladder and stabbing board means.
Yet a further object of the present invention is to provide a stabbing board arrangement for access from a drilling mast floor including guide track means which may be secured in generally vertically extending relationship with the drilling mast, stabbing board means, carriage means to support the stabbing board means for movement along the guide track means, means to raise and lower the carriage means along the guide track means, ladder means connected with the stabbing board means and depending downwardly therefrom for access to the stabbing board means from the drilling mast floor and wherein the stabbing board means includes platform means pivotally connected to the carriage means for extending laterally relative to the guide track means, vertically extending guard rail means pivotally connected to the platform means, handrail means pivotally connected to the guard rail means and to the carriage means in upper spaced relation to the platform means and counterweight means on the platform means whereby the platform means, guard rail means and handrail means may be pivoted upwardly to a collapsed position generally parallel aligned with said guide track means when not in use.
Other objects and advantages of the present invention will become more readily apparent from a consideration of the following drawings and description.
Fig. 1 is a vertical elevational view of the stabbing board arrangement of the present invention illustrating it in position in a drilling mast which is shown in dotted line; Fig. 2 is a side view of the casing stabbing board arrangement positioned in a drilling mast; Fig. 3 is an enlarged side view illustrating in greater detail further components of the present invention and showing in dotted line the collapsed position of the casing stabbing board; and Fig. 4 is a sectionai view on the line 4-4 of Fig. 3 showing the preferred form of the guide track means and a form of carriage means supported for movement along the guide track means.
Attention is first directed to Figs. 1 and 2 of the drawings wherein a portion of an upwardly extending drilling mast is referred to by the numeral 10. Guide track means are illustrated as being in the form of a longitudinally extending quadrilateral 1 5. Longitudinally spaced brace means as represented at 1 6 and better seen in Fig. 4 extend between the quadrilateral 1 5 and the lateral braces represented at 17 of the drilling mast 10 to secure the longitudinally extending guide track means 1 5 in vertically extending position in the drilling mast 10.
The vertically extending guide track means 1 5 may be positioned at any desired elevation in the drilling mast 10, and under normal drilling conditions as presently employed, it is desired that the guide track means 1 5 when in use be positioned within the mast 10 to enable the casing stabbing board represented generally at 20 to be positioned anywhere from approximately 23 feet to approximately 47 feet above the floor 21 ' of the drilling mast 10.
A reversible motor means 25 is mounted on plate 1 5f on the upper end of guide track means 15 as shown in Fig. 3. The motor 25 is operatively connected with a drum or cable winch 26. The cable winch 26 has wound thereon a cable 27, one end 28 of which is connected to carriage means referred to generally at 30 and with which the casing stabbing means referred to generally by the numeral 20 is pivotally connected whereby the carriage means 30 and supported stabbing board means 20 may be moved up and down along the guide track means 1 5. Ladder means referred to generally at 35 is secured to the carriage means 30 adjacent the stabbing board means so that it is movable with the carriage means 30 and supported casing stabbing board means 20.
Safety cable means represented generally at 40 and comprising the longitudinally extending cables 41 and 42 which are connected at their respective upper ends 41a and 42a to the plate 1 5f adjacent the upper end of the guide track means 1 5 and at their respective lower ends 41 b and 42b to the plate 1 5e at lower end of the guide track means 15 as shown in Fig. 1 of the drawings are provided for stopping movement of the stabbing board means 20 in the event that the load cable means 27 should break or motor means 25 fail and release the load represented by the stabbing board means 20 and carriage means 30 and any operator supported on the stabbing board means 20. Cooperating with the safety cables 41 and 42 is a safety harness S which includes a safety catch or lock 45 of well known configuration.The safety harness S is connected between the carriage means 30 and the lower end 28 of cable 27 and the safety lock 45 movably engages with the cables 41 and 42, as better illustrated in Fig. 3 of the drawings, for arresting movement of the carriage means 30 and stabbing board means 20 in the event that the main load line cable 27 breaks, or if motor means 25 fails and releases the carriage means for free fall. This will be described in greater detail hereinafter.
Control means are provided to supply power to actuate the motor means 25 and drum means 26 to either wind or unwind the main load line cable 27 connected to the carriage means 30 and effect raising or lowering of the carriage means 30 and supported stabbing board means 20, such control means including the power control means represented generally by the numeral 50 in Fig. 3 and including the control line means referred to generally by the numeral 55 in Fig. 3.
As illustrated in Fig. 4, the guide track means 1 5 is preferably a quadrilateral having the flat sides 1 spa, 1 sub, 1 sic and 1 sod as illustrated. It is provided with a transverse member 1 sue at its lower end which functions as a lower stop for carriage rneans 30, and an upper intermediate stop (not shown) spaced below plate 1 5f may be provided on the guide track means 1 5 if desired to limit the extent of the upward movement of the stabbing board means 20.
The carriage means 30 includes a longitudinally extending frame member referred to generally at 31 in Fig. 4 and including two sides 31 a and 31 b which are connected together and extend generally at right angles to each other as illustrated in Fig. 4. Roller support means in the form of plates 33 are secured adjacent the upper and lower ends of each of the sides 31 a and 31 b by any suitable means such as welding or the like.
Rollers 36 are provided on shafts 37 which shafts are secured in position on the plates 33 by suitable means such as the nut 37a. Each roller 36 fits between the enlargements 37b and 37c on shaft 37 as shown in the drawings whereby such rollers 36 are rotatably supported for engagement with the four sides of the guide track means 1 5.
As illustrated in Fig. 3 and 4 of the drawings, the upper plates 33 each supports an upper roller 36, one of which rollers engages the side 1 5a and the other roller engages side 1 5b of the quadri lateral. A pair of lower plates 33 extends below the carriage means 30 and is secured thereto. A lower roller 36 is supported in a manner as described above with regard to the upper rollers on one lower plate 33 and another lower roller 36 is supported on the other of the pair of plates 33. One lower roller 36 engages the side 1 sic and the other roller engages the side 1 5d of the quadrilateral 1 5.It will be noted that the upper rollers 36 are in the same general transverse or horizontal plane relative to the longitudinal axis of the vertically extending guide track means of quadrilateral 1 5. Similarly, the lower rollers 36 are in the same horizontal plane which is spaced longitudinally relative to the upper rollers 36 as shown in the drawings.
Further, each of the upper rollers 36 is in an opposed relationship to the lower rollers 36 as better illustrated in Fig. 4 of the drawings. For example, the upper roller 36 which engages side 1 5 of guide track 15 is opposite lower roller 36 which engages side 15d of guide track 15; upper roller 36 which engages side 15b is opposite lower roller 36 which engages side 1 5c. The stabbing board means 20 is secured by any suitable means to the carriage means 30, one form being described hereinafter, whereby the stabbing board means is secured to and movable with the carriage means 31.
As noted previously, the main load cable 27 which has one end 28 secured to the carriage means 30 as shown in Fig. 3 of the drawings, extends longitudinally of the guide track means 1 5 and is reeved or received on the drum or winch 26 supported on suitable means such as the plate 15f at the upper end of the guide track means 1 5.
The lower end 28 of the cable 27 is connected to a safety harness represented by the letter S, which safety harness is of well known design, construction and function. The safety harness is connected by means of the connection represented at 30a to a transverse support (not shown) forming part of the carriage means 30.
End plate members 30b are mounted at each end of such transverse support (not shown), and the transverse support is in turn secured to longitudinal frame member 31 of carriage means 30.
The safety harness represented at S, in Fig. 3, is provided with a safety catch or safety lock 45 forming part of the harness S associated or connected with the carriage means 30, which safety lock means 45 is movably engaged with the safety cables 41,42 and travels therealong as the carriage means 30 moves up and down along the track means 1 5. In the event of an accident such that the cable means 27 should become severed or broken, or if the motor means 25 fails, the load is relieved from the safety harness S, and removal of the load from the main load line 27 actuates the safety harness S and associated safety lock 45 so that the lock 45 grips the safety cables 41,42 and stops or locks the carriage means 30 and stabbing board means 20 to the safety cables 30 to prevent any free fall of the carriage means 30, stabbing board means 20 and ladder 35 along the guide track means 1 5.
The stabbing board means 20 includes a horizontal platform 20d pivotally connected as represented at 20e to the plate members 30b of carriage means 30. The platform 20d is defined by the laterally spaced horizontal side runners 21 with a suitable horizontal support surface extending between the side runners 21 to support an operator thereon. A horizontal end member 21 c better seen in Fig. 1 extends between the side runners 21 at their outer ends. Other lateral bracing beneath the horizontal support and between the side runners 21 may be provided as desired. The outer end 20f of the side runners 21 is pivotally or hingedly connected as represented at 21 a to the vertically extending guard rail means 20g, with a guard rail being provided adjacent the end of each of the laterally spaced side runners 21.The guard rail means 209 are provided with lateral bracing 21 x therebetween as better seen in Fig. 1 and the guard rail means 20g are pivotally connected at their upper ends as represented at 20h to the laterally spaced, horizontal handrail means 20i which handrails are spaced upwardly from the platform 20d as illustrated in the drawings: The inner ends 20j of the side handrails 20i are pivotally connected to a transverse member 20c extending therebetween which transverse member is in turn connected to the members 20a and 20b which extend from the transverse member 20c and are secured to the longitudinally extending frame member 31 of carriage 30 as illustrated in the drawings.Each of the side runners 21 of the platform 20d is provided with a counterweight 20k which retains the stabbing board means 20 in the dotted line position generally parallel to the guide track means 1 5 when it is collapsed as illustrated by the letter C in Fig. 3.
The reversible motor 25 may be electrically, hydraulically or pneumatically actuated, and as described, will be described as being pneumatically actuated. The control means 50 includes three way valve means represented at 50a which is actuated by the cross arm or lever 58. The connection of lever 58 with valve means 50a is such that the cross arm automatically moves to a horizontal position as shown which is the off position and prevents flow of air to the reversible motor 25 when not actuated. The valve means 50a is mounted in support 50b which support is in turn secured to upper plate 15f at the end of guide track means 1 5. It is connected to supply power to motor means 25.
The control line means 55 comprise a pair of control lines 56 and 57 the upper ends of each of which are connected to the outer end of an actuating cross arm or lever 58 forming part of the three way valve 50a. The cables 56 and 57 extend longitudinally of and are in spaced relation to the guide track means 15 and extend through suitable openings in the lower end plate 1 sue to terminate at their lower ends as represented in Fig. 3 at any suitable height, for example, about six feet above the floor 21 ' of the drilling mast.
When it is desired to lower the ladder means 35 to enable a stabbing board operator to gain access to the stabbing board means 20 to perform stabbing operations, the cable 56 is grasped and manually pulled. This is transmitted to and pivots the cross arm 58 to operate the valve means 50a so as to supply power to the motor 25 in a manner to rotate winch 26 and unwind cable 27 so that the carriage means 30, supported stabbing board 20 and ladder means 35 is lowered along the guide track means 1 5. Such lowering is continued until the ladder means 35 is moved to a position such as represented at dotted line in Fig. 2 to enable the casing board operator to mount the ladder directly from the floor 21' of the drilling mast. The cable 56 is released and the operator climbs ladder 35 and moves stabbing board 20 to a horizontal position so that he can get on it.The other cable 57 is then grasped and manually pulled. This pivots cross arm 58 in the opposite direction and supplies power to motor 25 so that it operates in an opposite direction and rotates winch 26 in an opposite direction to pull on the main load line 27 so that the carriage means 30, supported stabbing board 20 with the operator thereon and ladder 35 are moved upwardly along the guide track means 1 5. When the desired elevation for the stabbing board means 20 is reached, the operator lets go of cable 57.
After use of the stabbing board means 20 is completed, the operator grasps cable 56 while on the stabbing board so that the motor 25 unwinds cable 27 to lower carriage means 30, stabbing board 20 and ladder means 35 until the lower end of ladder 35 is adjacent the floor 21'. The operator releases cable 56 which stops cable 27, carriage means 30 and ladder 35. He then sidesteps onto the ladder 35 and pivots the stabbing board to the colapsed position represented at C in Figs. 2 and 3 so that normal well operations may proceed.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

Claims (14)

Claims
1. A stabbing board arrangement for access from a drilling mast floor comprising: a. guide track means for securing in generally vertical extending relationship with the mast; b. stabbing board means; c. carriage means to support said stabbing board means for movement along said guide track means; d. means to raise and lower said carriage means along said guide track means; and e. ladder means connected with said carriage means and depending downwardly therefrom for access to said stabbing board means from the drilling mast floor.
2. The arrangement of claim 1 including control means for actuating said raising and lowering means.
3. The arrangement of claim 1 wherein said stabbing board means includes: (1) platform means pivotally connected to said carriage means for extending laterally relative to said guide track means; (2) vertically extending guard rail means pivotally connected to said platform means; (3) handrail means pivotally connected to said guard rail means and to said carriage means in upper spaced relation to said platform means; and (4) counterweight means on said platform means whereby said platform means, guard rail means and handrail means may be pivoted upwardly to a collapsed position generally parallel aligned with said guide track means.
4. The arrangement of claim 1 wherein said means to raise and lower said stabbing board includes: (1) rotatable drum means mounted adjacent the upper end of said guide track means; (2) load cable means supported on said drum means and connected at one end to said carriage means; (3) reversible motor means connected to said drum means for rotation thereof whereby said load cable means may be wound on, and unwound from said drum to raise and lower said carriage means and stabbing board means; (4) safety cable means extending longitudinally of and connected to the upper and lower ends of said guide track means; and (5) safety lock means connected to said carriage means and movably engageable with said safety cable means as said carriage means moves up and down along said guide track means, said safety lock means acting upon removal of load from said load cable means in the event of an accident to lock said carriage means to said safety cable means.
5. The arrangement of claim 2 wherein said control means includes: (1) power control means to control the flow of power to said reversible motor means; and (2) control line means connected to said power control means and extending longitudinally of said guide track means to terminate in spaced relation to the drilling mast floor whereby said control line means may be manually actuated from the drilling mast floor to lower said carriage means and supported stabbing board means and ladder for access to said ladder and stabbing board means.
The arrangement of claim 5 wherein said control line means comprises a pair of lines extending longitudinally of said guide track means and connected at one end to said power control means whereby manual movement of one of said pair of lines actuates said power control means for the flow'of power to rotate said motor means in one direction and thereby move said carriage means along said guide track means in one direction, and manual movement of the other of said pair of lines actuates said power control means for the flow of power to rotate said motor means in the other direction and thereby move said carriage means along said guide track means in the other direction.
7. The arrangement of claim 6 wherein said control means automatically returns to a position to cut off the flow of power when neither of said pair of lines is manually moved.
8. The arrangement of claim 1 wherein said carriage means includes roller support means for supporting roller means in longitudinally spaced relationship for engagement with said guide track means.
9. The arrangement of claim 1 wherein said guide track means comprises a quadrilateral column.
1 0. The arrangement of claim 9 wherein said carriage means includes: (1) a longitudinally extending frame member having two sides which extend at right angle relationship; (2) longitudinally spaced roller support means mounted on each of said two sides; (3) roller means supported on said roller support means, said roller means comprising upper roller means engaging two of the sides of said quadrilateral column, and lower roller means engaging the other two sides of said quadrilateral column in opposed relation to said upper roller mean to support said carriage means for movement along said quadrilateral column.
11. The arrangement of claim 5 wherein said power control means is a self-centering valve means.
12. In a stabbing board arrangement for use with a drilling mast wherein a guide track is positioned in generally a vertical relationship on a drilling mast with carriage means movable longitudinally of the guide track and having a stabbing board carried by the carriage means, the invention comprising a ladder secured to the carriage adjacent the stabbing board and extending downwardly therefrom whereby it may be lowered with the carriage to adjacent the drilling floor to provide access to the stabbing board directly from the drilling floor.
13. The invention of claim 12 wherein the stabbing board is pivotally secured to said carriage means and includes counterweight means whereby it may be collapsed to a generally parallel relationship with the guide track.
14. A stabbing board arrangement for access from a drilling mast floor substantially as hereinbefore described with reference to and as illustrated in the various figures of the accompanying drawings.
GB08230632A 1982-05-10 1982-10-27 Stabbing board arrangement for drilling mast Withdrawn GB2119749A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US37678182A 1982-05-10 1982-05-10

Publications (1)

Publication Number Publication Date
GB2119749A true GB2119749A (en) 1983-11-23

Family

ID=23486462

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08230632A Withdrawn GB2119749A (en) 1982-05-10 1982-10-27 Stabbing board arrangement for drilling mast

Country Status (1)

Country Link
GB (1) GB2119749A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996008631A1 (en) * 1994-09-13 1996-03-21 Richardson Allan S Portable top drive
US5921329A (en) * 1996-10-03 1999-07-13 Sundowner Offshore Services, Inc. Installation and removal of top drive units
US8297405B2 (en) * 2009-01-15 2012-10-30 Superior Rig Solutions, Inc. Adjustable work platform for pipe and casing stabbing operations

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001308A1 (en) * 1979-10-31 1981-05-14 G Beeche Folding scaffold system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001308A1 (en) * 1979-10-31 1981-05-14 G Beeche Folding scaffold system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996008631A1 (en) * 1994-09-13 1996-03-21 Richardson Allan S Portable top drive
US5755296A (en) * 1994-09-13 1998-05-26 Nabors Industries, Inc. Portable top drive
US6024181A (en) * 1994-09-13 2000-02-15 Nabors Industries, Inc. Portable top drive
US5921329A (en) * 1996-10-03 1999-07-13 Sundowner Offshore Services, Inc. Installation and removal of top drive units
US8297405B2 (en) * 2009-01-15 2012-10-30 Superior Rig Solutions, Inc. Adjustable work platform for pipe and casing stabbing operations
US8800716B2 (en) 2009-01-15 2014-08-12 Superior Rig Solutions Inc. Adjustable work platform for pipe and casing stabbing operations

Similar Documents

Publication Publication Date Title
EP1761454B1 (en) Window crane
US5927440A (en) Mobile hoist system and method
US4474263A (en) Derrick elevator
JP3202055B2 (en) Assembled scaffold movable within the elevator shaft for mounting shaft equipment
US4133067A (en) Articulating gangway
SG193723A1 (en) Motorized height access device for tower cranes
JPH0677607B2 (en) Rescue craft
US4081087A (en) Pipe laydown and pickup machine
US9222306B2 (en) Crane access staircase and mounting system
US4530648A (en) Wall climbing form hoist
US5704755A (en) Panel lifting hoists
US5842928A (en) Amusement park swing ride
US3394776A (en) Suspended traveling scaffold
GB2119749A (en) Stabbing board arrangement for drilling mast
US5074382A (en) Offshore access systems
US7493737B2 (en) Roofing apparatus
US4106150A (en) Elevated loading platform
JP3662064B2 (en) Manual lifting floor device
US7232009B1 (en) Ascension/descension apparatus and method
JP2000084100A (en) Ladder safety device
JPH0240076Y2 (en)
WO1998047808A1 (en) Lifting apparatus
JP2557659Y2 (en) Lifter in aerial work vehicle
US5109957A (en) Offshore access systems
US1376253A (en) Elevator

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)