US3602413A - Surface apparatus for handling an elastic column - Google Patents
Surface apparatus for handling an elastic column Download PDFInfo
- Publication number
- US3602413A US3602413A US856338A US3602413DA US3602413A US 3602413 A US3602413 A US 3602413A US 856338 A US856338 A US 856338A US 3602413D A US3602413D A US 3602413DA US 3602413 A US3602413 A US 3602413A
- Authority
- US
- United States
- Prior art keywords
- gripping
- axis
- devices
- column
- elastic column
- 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.)
- Expired - Lifetime
Links
- 238000006073 displacement reaction Methods 0.000 claims abstract description 27
- 230000009471 action Effects 0.000 claims abstract description 23
- 238000000034 method Methods 0.000 claims description 8
- 229920001971 elastomer Polymers 0.000 claims description 4
- 239000000806 elastomer Substances 0.000 claims description 4
- 239000000725 suspension Substances 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 description 9
- 238000005553 drilling Methods 0.000 description 6
- 239000012530 fluid Substances 0.000 description 6
- 230000002441 reversible effect Effects 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000013013 elastic material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000000979 retarding effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
- E21B19/22—Handling reeled pipe or rod units, e.g. flexible drilling pipes
Definitions
- This apparatus is provided with at least two devices for gripping an elastic column, including a lower and an upper gripping devices, one at least of these devices being displaceable along the axis of the c'olumn in a released position.
- the present invention relates to a surface apparatus whereby an elastic column, particularly a column introduced into a borehole drilled through the ground can be handled, i.e. lowered into the borehole and raised back to the ground surface.
- This column may, for example, by a flexible drill pipe used in the drilling process wherein is substituted for the usual string of rigid stems a continuous flexible pipe at the lower end of which a bottom motor is directly connected to a drill bit for actuation thereof.
- the handling apparatus according to the invention is of a type provided with devices for gripping the elastic column, some of these gripping devices being movable along the column.
- a first object of the invention is to provide an apparatus which may be associated with conventional equipments used in conventional drilling methods, such as derricks, hoisting devices using winches, cables and pulley blocks, without requiring any substantial change in these equipments.
- the main object of the invention is to provide an apparatus for handling an elastic column capable of supporting loads which may reach many hundred tons, with an elongation of this column, relative to the gripping device, under the action of the load, which does not lead to deteriorations of the walls of this column which are in contact these gripping devices, or to creeping phenomena of this column, relative to the gripping devices applied thereto.
- the apparatus includes at least two devices for gripping the elastic column, .comprising a lower and an upper gripping devices, each of said devices being associated with means for displacing at least one of said devices parallelly to the column axis, means for sequentially controlling said displacing means and for generating a gripping action on said column through either of said gripping devices, so that there is always at least one of said gripping devices in its gripping position, the displacement of said gripping devices being effected in a first direction in the gripping position of the device and in the opposite direction in the released position of this device.
- each of said upper and lower devices for gripping the column is constituted by a plurality of separate elements, or gripping belts, arranged in series, suspended from one and the same support means, adapted to permit a relative displacement of said gripping belts with respect to each other, under the action of the load to which each of said gripping belt is subjected.
- FIG. I diagrammatically illustrates an overall view of the apparatus
- FIG. 2 illustrates a gripping belt
- FIGS. 3, 3a and 3b diagrammatically illustrate an embodiment of the means according to the invention for suspending the gripping belts in each of the lower and upper gripping devices;
- FIG. 4 diagrammatically shows the relative displacement of the gripping belts, permitted by the arrangement according to the invention.
- FIG. 5 diagrammatically illustrates an embodiment of the synchronized control means of the apparatus.
- FIG. I which diagrammatically shows an overall view of a drilling equipment for a flexible drill pipe including an ap-
- the pipe 1 is stored on a winch 4 associated with means for supplying the pipe with drilling fluid through a rotary coupling and passes between this winch and pulley 3 through a tension regulating device diagrammatically represented at 5, the winch 5 and the tension regulating device 5 forming however no part of the present invention.
- This lower gripping device 6 is stationary, being integral with the substructure 7 of the derrick.
- the apparatus in combination with this stationary lower gripping device, includes an upper gripping device 8 for the pipe I, this device being also constituted by a series of gripping belts, each of which is provided with jaws associated with a reversible device for displacing these jaws in a direction transverse to the pipe.
- This upper device is movable vertically over a stroke Lalong the pipe, in the released position of its jaws.
- the means providing for the displacement of the upper gripping device 8 of the pipe along this pipe I is constituted by a hoisting device of the type used in the rotary drilling method for handling the drill string and its elements.
- This device includes cables 9 passing over a'stationary pulley block 10 located at the top of the derrick (this stationary pulley block includes for example two pulleys located on both sides of pulley 3) and over a traveling block 11 from which is suspended the upper gripping device 8, by means of a hook 12.
- the vertical displacements of the traveling block 11 are achieved by means ofa winch 13 on which is wound a free end 9a of cables 9.
- the device according to the invention includes means for synchronously controlling on the one hand the means for displacing the upper gripping device 8 (winch 13 in the illustrated embodiment) and on the other hand the means for moving the jaws of the two gripping devices 6 and 8 into and out of gripping position.
- FIG. 2 diagrammatically illustrates the structure of an element or gripping belt constituting each of the gripping devices 6 and 8.
- This element includes at least two gripping jaws for the pipe 1 (jaws l and 16) which may grip the pipe 1 by means of reversible hydraulic jacks 17a, 17b which bear against a tubular housing 18 whereon these jacks are articulated.
- the jaws l5 and 16 roll on rollers along inclined guide paths integral with this tubular housing.
- jaws and their guide paths constitute and automatic gripping system so designed as to exert on the pipe a gripping action always proportional to the downwardly directed vertical force (indicated by the arrow in FIG.'2) to which it is subjected as a result of friction between the jaws and the pipe, this arrangement being a safety factor.
- each of the jaws l5 and 16 is constituted by two superimposed wedges integral with each other.
- the reference numerals 37, 38, 39 and 40 designate rollers the axes of which are carried by jaws l5 and 16, these rollers rolling along inclined guide paths 41 to 44 carried by the tubular housing 18.
- Each gripping element or belt may obviously be provided with more than two gripping jaws, distributed along the periphery of the flexible pipe 1.
- each gripping belt such as the one shown by FIG. 2, the relative elongation of the pipe I, with respect to the gripping jaws will be reduced since each gripping belt only supports a fraction of the overall load supported by each of the gripping devices 6 and 8 and because moreover the length of the pipe 1 passing through this belt is only a fraction of the overall length of the pipe I, passing through each of the gripping devices 6 and 8.
- each gripping jaw such as jaw or jaw 16 with an internal coating or shoe made of an elastomer on the internal wall of this jaw which comes into contact with pipe 1, or to fix the shoe to a pad made of an elastic material, such as an elastomer.
- FIGS. 3, 3a and 31 show the arrangement according to the invention of the gripping belts constituting each of the gripping devices 6 and 8.
- the belts mounted in series are four in number, but this number should by no way be considered as limitative.
- the number n of gripping elements or belts constituting each gripping device will be selected sufficiently high so that,
- the maximum load W/n to be supported by each gripping belt will correspond to a tolerable elongation of the portion of column passing through this gripping element.
- the different elements or belts for gripping the column 1 (elements 18b, 18c, 18d) arranged in series for constituting each of the gripping devices 6 and 8 of FIG. 1 are suspended through rocking levers such as the rocking levers 21 and 22 (FIGS. 3 and 3a) from one and the same support member 23, by means of rods 124a, 124b, 1240, 124d for the rocking lever 21 and of corresponding rods for the rocking lever 22.
- each suspension rod is connected through a ball and socket joint to the element which this rod supports. for example at 26 for the rod 124a.
- each gripping belt with respect to the adjacent belt is limited by a slot 127a provided on one ofthese belts, a stud 128a integral with the other belt being vertically displaceable within this slot.
- the assembly of the gripping belts is contained in a housing 29 internally provided with means, such as rollers 30, 31 32 and 33, for guiding the gripping belts.
- Such an arrangement enables the gripping belts to perform relative vertical movements through the inclination of the rocking levers, permitted by the ball and socket joints to 136, following (FIG. 4) the elongation of the pipe under the action of the weight W applied to this pipe.
- the reversible jacks 21a to 28a controlling the jaws 21b to 28b of the upper gripping device 8 and the jacks 29a to 36a of the jaws 29b to 36b of the lower gripping device 6 are supplied with hydraulic fluid from a tank 45 by means of a motor-pump unit P through two slide valves 46 and 47 which are mechanically interconnected, so as to be displaced synchronously.
- An arm 49 providing for electrical contact and forming a T with the connecting rod 48 integral with this arm provides for synchronous control of the actuation of the winch l3 and of that of the jaws, by closing electrical contacts: contact M for actuating the winch so as to raise the movable upper gripping device 8, contact 0 for stopping the winch and contact D for disconnecting the winch 13, so as to enable the device 8 to be lowered under the action of the load, with a braking effect performed by the winch.
- F designates a filter
- the device such as 53 and 54 are nonreturn valves
- 55 a pipe supplying hydraulic fluid makeup so as to compensate for the losses in the hydraulic circuit (this makeup supply of fluid is for example achieved from gauged oleopneumatic accumulators)
- 56 designates a safety valve.
- the device such as 57 and 58 are device for regulating the flow rate of the hydraulic fluid supplied to the jacks during gripping or releasing movement of the jaws respectively.
- the arm 49 for electric contact comes onto the contact M, which so actuates the winch 13 as to raise the gripping device 8.
- a not illustrated device such as an electric retarding device, may be used so that the actuation of winch 13 be efing slide valves 46 and 47, by electrically controlling the elec-.
- This control may either be manual, by actuating an electrical switch (not shown) or made fully automatic by using a programming device which may be of any suitable known type, for example a drum driven in rotation at a constant speed and provided around its periphery with electrical contacts having the shape of annular sectors which will successively actuate, at predetermined instants which are functions of their respective positions on the drum, a switch located in the immediate vicinity of this drum and controlling the electrovalve 50.
- This programming may also be achieved by automatic controlling based on the displacements of the upper gripping device, for example by means of photoelectric cells located at suitable levels, at the upper and lower ends of the stroke of this upper gripping device.
- the weight W of the flexible line 1 which is supported by each of the gripping devices 6 and 8 alternatively (this weight varying moreover as a function of'the unreeled length of the flexible pipe) is taken up by successively moving into gripping position the different belts which constitute each of these devices (dephased" gripping), by first moving into gripping position in each gripping belt the belt whose displacement, under the action of the load, is the smallest, the belts being moved out of gripping position by following the reverse order.
- the gripping the the flexible pipe 1 by the upper gripping element 8 in the lowermost position of the latter may be achieved by first moving into gripping position the jaws 21b and 22b (FIG. 5) of the upper belt of this gripping device and by increasing through actuation of the winch the load sup ported by this belt up to about 40 tons, after the automatic clamping action has been initiated, while the lower gripping element 6 is at the same time progressively unloaded.
- the jaws 23b, 24b of the nearest lower belt are then moved into gripping position without waiting" that the jaws 21b, 22b have reached their maximum load of 50 tons.
- This method of gripping wherein a belt is placed into gripping position without waiting that the previously actuated belt has reached its maximum load, results in an elongation of the pipe between these two belts, with respect to its position at the instant of the beginning of the gripping action by the lower belt, such an elongation occurring during the above-defined overlapping period (for example when the load of the upper belt of the gripping device continues to increase from the value 40 tons, corresponding to the beginning of the gripping action of the next belt, up to its maximum value 50 tons).
- the arrangement, according to the invention, of the gripping belts inside each of the gripping devices 6 and 8, such as illustrated in FIG. 3, permits a relative displacement of the belts, corresponding to the elongation of the flexible pipe between these belts in there gripping position.
- both gripping devices may be movable along the axis of the pipe over a stroke C, so that the displacement of one of the gripping devices in its released position is effected during the displacement of the other gripping device in its gripping position.
- a surface apparatus for handling an elastic column provided with at least two devices for gripping the elastic column, including a lower gripping device and an upper gripping device, each of said gripping devices being associated with means for placing said devices into and out of gripping position, means for displacing at least one of said gripping devices along the axis of the column, means for sequentially actuating said displacing means, adapted to always maintain at least one of said gripping devices in its gripping position and to perform the displacement of said gripping device successively in a first direction corresponding to the gripping position of this device and in the opposite direction corresponding to the released position of said gripping device, each of said gripping devices being constituted by a plurality of separate gripping elements arranged in series and means for suspending each of said gripping elements from one and the same support member permitting the relative displacement of said gripping elements with respect to one another along the axis of the elastic column under the action of the load to which each of said gripping elements is subjected.
- suspension means is constituted by an assembly of rigid rods so articulated as to form a system of rocking levers permitting the relative displacement of said gripping elements through the inclination of said rocking levers.
- each of said gripping devices includes a housing wherein are located said gripping elements, said housing being adapted for guiding said gripping elements during their displacement along the axis of the elastic column.
- said gripping element includes a housing provided with means for gripping the elastic column, said gripping means including at least two gripping jaws having a gripping surface substantially parallel to the axis of the column, each of said jaws being slidable along'a guide path integral with said housing and inclined with respect to the column axis so as to downwardly come closer to this axis, thereby being adapted to perform an automatic clamping action on the elastic column, when the latter is subjected to a vertical downwardly directed tension, each of said jaw being actuated by jack means articulated to said housing and to said jaw, said jack means being adapted to move the jaw closer to the axis of the elastic column in its gripping position and to move the jaw away from this axis in its released position.
- each of said jaws is provided with at least one roller which can roll along said inclined guide path.
- said jack means is adapted to move said jaw away from the axis of the elastic column against the action of an elastic device adapted to automatically move said jaw toward this axis in the absence of any action of said jack means on said jaw.
- said first element being that for which the displacement relative to its initial position, as a result of the applied load, is the smallest, then is actuated the gripping element adjacent to said first gripping element when said first element is substantially in its gripping position, and so on for the different gripping elements of said gripping device.
Landscapes
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Load-Engaging Elements For Cranes (AREA)
- Earth Drilling (AREA)
- Surgical Instruments (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR166283 | 1968-09-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3602413A true US3602413A (en) | 1971-08-31 |
Family
ID=8654559
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US856338A Expired - Lifetime US3602413A (en) | 1968-09-10 | 1969-09-09 | Surface apparatus for handling an elastic column |
Country Status (9)
Country | Link |
---|---|
US (1) | US3602413A (xx) |
JP (1) | JPS4821681B1 (xx) |
CA (1) | CA921459A (xx) |
DE (1) | DE1945590C3 (xx) |
ES (1) | ES371357A1 (xx) |
FR (1) | FR1602113A (xx) |
GB (1) | GB1265338A (xx) |
NL (1) | NL162454C (xx) |
SE (1) | SE356787B (xx) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3999610A (en) * | 1974-11-21 | 1976-12-28 | Otis Engineering Corporation | Pipe snubbing method and apparatus |
US4448393A (en) * | 1981-03-28 | 1984-05-15 | Willy Habegger Ag | Apparatus for pulling in and letting out a cable |
WO1989010892A1 (en) * | 1988-04-28 | 1989-11-16 | Amca International Corporation | Deepwater extended hook travel attachment |
US6450385B1 (en) * | 1998-05-13 | 2002-09-17 | Coflexip | Clamping ring in particular for oil duct |
EP1331191A1 (en) * | 2002-01-25 | 2003-07-30 | IHC Gusto Engineering B.V. | Floating lifting device |
CN105239948A (zh) * | 2015-10-28 | 2016-01-13 | 新奥气化采煤有限公司 | 解卡装置及具有该解卡装置的连续管注入装置 |
US20170015522A1 (en) * | 2014-12-11 | 2017-01-19 | China University Of Mining And Technology | Tensioning device and tensioning method for steel wire rope of cage guide of ultra-deep vertical shaft |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2430385A1 (fr) * | 1978-07-04 | 1980-02-01 | Coflexip | Dispositif de manutention a pinces de cables ou conduites tubulaires notamment pour installations sur les puits |
GB2242728B (en) * | 1990-04-04 | 1994-04-20 | Stc Plc | Cable stopper |
US6116345A (en) * | 1995-03-10 | 2000-09-12 | Baker Hughes Incorporated | Tubing injection systems for oilfield operations |
US5850874A (en) * | 1995-03-10 | 1998-12-22 | Burge; Philip | Drilling system with electrically controlled tubing injection system |
AU730344B2 (en) * | 1996-04-19 | 2001-03-08 | Baker Hughes Incorporated | Tubing injection systems for land and under water use |
WO1998014686A1 (en) * | 1996-10-02 | 1998-04-09 | Baker Hughes Incorporated | Tubing injection system for oilfield operations |
US7281588B2 (en) | 2003-12-19 | 2007-10-16 | Schlumberger Technology Corporation | Tubular injector apparatus and method of use |
US7810555B2 (en) | 2004-12-16 | 2010-10-12 | Schlumberger Technology Corporation | Injector apparatus and method of use |
CN109665293A (zh) * | 2019-02-27 | 2019-04-23 | 岳西十行机械设备有限公司 | 一种纤维连续化卸料方法 |
-
1968
- 1968-09-10 FR FR166283A patent/FR1602113A/fr not_active Expired
-
1969
- 1969-09-04 NL NL6913491.A patent/NL162454C/xx not_active IP Right Cessation
- 1969-09-04 GB GB1265338D patent/GB1265338A/en not_active Expired
- 1969-09-04 SE SE12247/69A patent/SE356787B/xx unknown
- 1969-09-05 CA CA061323A patent/CA921459A/en not_active Expired
- 1969-09-09 DE DE1945590A patent/DE1945590C3/de not_active Expired
- 1969-09-09 US US856338A patent/US3602413A/en not_active Expired - Lifetime
- 1969-09-09 ES ES371357A patent/ES371357A1/es not_active Expired
- 1969-09-10 JP JP44071303A patent/JPS4821681B1/ja active Pending
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3999610A (en) * | 1974-11-21 | 1976-12-28 | Otis Engineering Corporation | Pipe snubbing method and apparatus |
US4448393A (en) * | 1981-03-28 | 1984-05-15 | Willy Habegger Ag | Apparatus for pulling in and letting out a cable |
WO1989010892A1 (en) * | 1988-04-28 | 1989-11-16 | Amca International Corporation | Deepwater extended hook travel attachment |
US4892202A (en) * | 1988-04-28 | 1990-01-09 | Amca International Corporation | Deepwater extended hook travel attachment |
US6450385B1 (en) * | 1998-05-13 | 2002-09-17 | Coflexip | Clamping ring in particular for oil duct |
WO2003062112A2 (en) * | 2002-01-25 | 2003-07-31 | Ihc Gusto Engineering B.V. | Floating lifting device |
EP1331191A1 (en) * | 2002-01-25 | 2003-07-30 | IHC Gusto Engineering B.V. | Floating lifting device |
WO2003062112A3 (en) * | 2002-01-25 | 2004-08-05 | Ihc Gusto Engineering B V | Floating lifting device |
US20050109724A1 (en) * | 2002-01-25 | 2005-05-26 | Nederlandsch Octrooibureau | Floating lifting device |
US7182212B2 (en) | 2002-01-25 | 2007-02-27 | Ihc Gusto Engineering B.V. | Floating lifting device |
US20170015522A1 (en) * | 2014-12-11 | 2017-01-19 | China University Of Mining And Technology | Tensioning device and tensioning method for steel wire rope of cage guide of ultra-deep vertical shaft |
US9708160B2 (en) * | 2014-12-11 | 2017-07-18 | China University Of Mining And Technology | Tensioning device and tensioning method for steel wire rope of cage guide of ultra-deep vertical shaft |
CN105239948A (zh) * | 2015-10-28 | 2016-01-13 | 新奥气化采煤有限公司 | 解卡装置及具有该解卡装置的连续管注入装置 |
CN105239948B (zh) * | 2015-10-28 | 2018-08-10 | 新奥科技发展有限公司 | 解卡装置及具有该解卡装置的连续管注入装置 |
Also Published As
Publication number | Publication date |
---|---|
SE356787B (xx) | 1973-06-04 |
NL162454B (nl) | 1979-12-17 |
ES371357A1 (es) | 1972-03-01 |
JPS4821681B1 (xx) | 1973-06-30 |
FR1602113A (xx) | 1970-10-12 |
NL6913491A (xx) | 1970-03-12 |
DE1945590A1 (de) | 1970-03-26 |
DE1945590B2 (de) | 1978-08-31 |
CA921459A (en) | 1973-02-20 |
NL162454C (nl) | 1980-05-16 |
DE1945590C3 (de) | 1979-04-26 |
GB1265338A (xx) | 1972-03-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3602413A (en) | Surface apparatus for handling an elastic column | |
US3840128A (en) | Racking arm for pipe sections, drill collars, riser pipe, and the like used in well drilling operations | |
US3503460A (en) | Pipe handling and centering apparatus for well drilling rigs | |
US3421581A (en) | Method and apparatus for carrying out operations on a well under water | |
US1972635A (en) | Drilling apparatus | |
US3681928A (en) | Method and apparatus for carrying out underwater well operations | |
NO151757B (no) | Anordning for kompensering av avstandsvariasjoner mellom en gjenstand opphengt fra en flytende baerer og havbunnen | |
US2885096A (en) | Pipe-handling apparatus for oil wells | |
US4099630A (en) | Pipe handling apparatus | |
EP0365672B1 (en) | Deepwater extended hook travel attachment | |
US2730246A (en) | Apparatus for handling pipe in a derrick | |
US3711000A (en) | Surface apparatus for handling an elastic column | |
US3837592A (en) | Device for automatically positioning the windings formed by a flexible elongated member stored in an annular basket rotatable about a vertical axis | |
WO2018145327A1 (zh) | 一种垂直提升装置及方法 | |
US2808166A (en) | Clamshell bucket closure attachment | |
US660477A (en) | Soaking-pit crane. | |
US2743823A (en) | Automatic racking device | |
KR840003578A (ko) | 화물 취급 장치 | |
US4341270A (en) | Drill string suspension tower | |
GB1340190A (en) | Stage scenery moving apparatus | |
US2747751A (en) | Apparatus for handling pipe in a derrick | |
US1904765A (en) | Means for torque control and automatic drill control | |
US20190360282A1 (en) | Drilling Unit Comprising an Electric Heave-Compensation System | |
PL66753B1 (xx) | ||
US3021918A (en) | Safety devices for lifting appliances |