 |
Claims  |
|
|
Having described my invention, I claim:
1. A torque wrench for tightening and breaking-out a threaded joint between
an upper end of a lower, vertically oriented pipe section, and a lower end
of an upper, vertically oriented pipe section, while the lower pipe
section is being supported so as to permit the upper pipe section to be
rotated with respect thereto about coinciding longitudinal axes of the
upper and lower pipe sections,
said torque wrench comprising:
a radially inner annulus which is split into two angularly complementary
halves;
a radially intermediate annulus which is split into two angularly
complementary halves;
a radially outer casing which is split into two angularly complementary
halves;
said inner annulus being mounted to said intermediate annulus for limited
angular movement of said inner annulus relative to said intermediate
annulus, about coinciding, vertically oriented longitudinal axes thereof;
said intermediate annulus being mounted to said casing for angular rotation
of said intermediate annulus relative to said casing, about coinciding,
vertically oriented longitudinal axes thereof;
means hinging and removably connecting said halves of said casing to one
another so that, when corresponding halves of said inner annulus, said
intermediate annulus and said casing are arranged on opposite sides of a
rotational longitudinal plane of division containing said longitudinal
axes of said annuli and said casing, said casing halves may be
disconnected, swing apart to an open condition, swing together to a closed
condition and reconnected;
means defining a vertically oriented central opening through said inner
annulus, adopted to receive and circumferentially surround a lower end of
an upper, vertically oriented pipe section;
each half of said inner annulus being provided with at least one clamping
jaw mounted for movement towards and away from the longitudinal axis of
said inner annulus respectively for centralizing and frictionally
engaging, and releasing said lower end of said upper, vertically oriented
pipe when said lower end of said upper, vertically oriented pipe section
is received in said central opening of said inner annulus;
means associated with said casing, for selectively rotating said
intermediate annulus with respect to said casing, about the longitudinal
axis of the intermediate annulus, in a desired angular direction;
means operatively connecting said intermediate annulus with said inner
annulus for effecting a limited extent of angular rotation of said inner
annulus relative to said intermediate annulus, in a desired angular
direction, when said means associated with said casing is used for
selectively rotating said intermediate annulus in a desired angular
direction; and
said operatively connecting means also being operatively connected with
said clamping jaws for moving said clamping jaws towards the longitudinal
axis of said inner annulus as said inner annulus is rotated to a limited
extent in one angular direction about said longitudinal axis of said inner
annulus, and for permitting said clamping jaws to move away from the
longitudinal axis of said inner annulus as said inner annulus is rotated
to a limited extent in an opposite angular direction about said
longitudinal axis of said inner annulus.
2. A torque wrench of claim 1, further comprising:
selectively activatable friction-generating brake means provided between
said casing and said inner annulus, for preventing, when activated,
angular rotation of said inner annulus relative to said casing about said
longitudinal axis of said casing.
3. The torque wrench of claim 1, wherein:
said operatively connecting means comprises at least one tangentially
arranged pressurized fluid-powered extensible-retractable piston and
cylinder arrangement having opposite ends pivotally connected respectively
to said inner annulus and said intermediate annulus.
4. The torque wrench of claim 3, wherein:
each said fluid-powered piston and cylinder arrangement is hydraulic
fluid-powered;
said clamping jaws are hydraulic fluid-powered for movement towards said
longitudinal axis of said inner annulus; and
said operatively connecting means is operatively connected with said
clamping jaws by hydraulic fluid line means.
5. The torque wrench of claim 4, further including:
a respective radially oriented guiding cylinder receiving each clamping jaw
and being mounted on said inner annulus for guiding movement of said
clamping jaws radially towards said longitudinal axis of said inner
annulus, for facilitating frictional engagement by said clamping jaws of
pipe sections of a range of different outer diameters.
6. The torque wrench of claim 4, wherein:
each said hydraulic fluid powered piston cylinder arrangement is
double-acting, whereby said clamping jaws, in use, are also forcibly
released.
7. The torque wrench of claim 1, wherein:
said intermediate annulus is mounted to said casing for 360.degree. angular
rotation of said intermediate annulus relative to said casing, about said
coinciding, vertically oriented longitudinal axes thereof.
8. The torque wrench of claim 1, wherein said means associated with said
casing, comprises:
a motor mounted between said casing and said intermediate annulus for
power-rotating said intermediate annulus relative to said casing about
said coinciding, vertically oriented longitudinal axes of said casing and
said intermediate annulus.
9. A roughneck assembly for tightening and breaking-out a threaded joint
between an upper end of a lower, vertically oriented pipe section, and a
lower end of an upper, vertically oriented pipe section, comprising:
a vertically oriented guide means;
a torque wrench mounted to said guide means, and a back-up wrench mounted
to said guide means, with said back-up wrench disposed below said torque
wrench, for supporting a lower pipe section against rotation about the
longitudinal axis of such lower pipe section, as said torque wrench is
used on an upper pipe section for rotating the upper pipe section with
respect to the lower pipe section about coinciding longitudinal axes of
said upper and lower pipe sections;
said torque wrench comprising:
a radially inner annulus which is split into two angularly complementary
halves;
a radially intermediate annulus which is split into two angularly
complementary halves;
a radially outer casing which is split into two angularly complementary
halves;
said inner annulus being mounted to said intermediate annulus for limited
angular movement of said inner annulus relative to said intermediate
annulus, about coinciding, vertically oriented longitudinal axes thereof;
said intermediate annulus being mounted to said casing for angular rotation
of said intermediate annulus relative to said casing, about coinciding,
vertically oriented longitudinal axes thereof;
means hinging and removably connecting said halves of said casing to one
another so that, when corresponding halves of said inner annulus, said
intermediate annulus and said casing are arranged on opposite sides of a
rotational longitudinal plane of division containing said longitudinal
axes of said annuli and said casing, said casing halves may be
disconnected, swing apart to an open condition, swing together to a closed
condition and reconnected;
means defining a vertically oriented central opening through said inner
annulus, adopted to receive and circumferentially surround a lower end of
an upper, vertically oriented pipe section;
each half of said inner annulus being provided with at least one clamping
jaw mounted for movement towards and away from the longitudinal axis of
said inner annulus respectively for centralizing and frictionally
engaging, and releasing said lower end of said upper, vertically oriented
pipe when said lower end of said upper, vertically oriented pipe section
is received in said central opening of said inner annulus;
means associated with said casing, for selectively rotating said
intermediate annulus with respect to said casing, about the longitudinal
axis of the intermediate annulus, in a desired angular direction;
means operatively connecting said intermediate annulus with said inner
annulus for effecting a limited extent of angular rotation of said inner
annulus relative to said intermediate annulus, in a desired angular
direction, when said means associated with said casing is used for
selectively rotating said intermediate annulus in a desired angular
direction; and
said operatively connecting means also being operatively connected with
said clamping jaws for moving said clamping jaws towards the longitudinal
axis of said inner annulus as said inner annulus is rotated to a limited
extent in one angular direction about said longitudinal axis of said inner
annulus, and for permitting said clamping jaws to move away from the
longitudinal axis of said inner annulus as said inner annulus is rotated
to a limited extent in an opposite angular direction about said
longitudinal axis of said inner annulus;
at least one of said torque wrench and said back-up wrench being vertically
adjustably movable on said guide means.
10. The roughneck of claim 9, further including:
a horizontally mobile carriage;
said guide means being supported on said carriage for horizontal movement
therewith. |
|
 |
|
 |
Claims |
|
|
|
Description |
|
|
BACKGROUND OF THE INVENTION
The invention relates to a torque wrench for tightening and braking-out
threaded joints between drill pipe and drill collar sections forming parts
of a drill string.
The background of the present invention includes the problems and the
amount of work needed related to inserting and unscrewing drill pipes on
the drill floor during drilling operations, particularly with regard to
inserting and removing a drill string into/from a drilling well in a
tripping operation.
During the last 10 to 20 years, hydraulic/mechanical equipment was
available to facilitate such operations. Equipment of this kind is called
a roughneck, and one concept is shown in U.S. Pat. No. 4,348,920. In
short, such a roughneck comprises a two-piece lower unit the lowermost
member of which forms back-up wrenches, whereas the upper member acts as a
torque tong or wrench. Such a wrench encircling grips a drill pipe joint,
and, in a conventional drilling operation, the back-up wrenches will clasp
the sleeve portion of the joint, and the torque wrench will clasp the tap
portion of the joint. The wrench causes the final torque make-up, or
breaking-out, respectively, between pipe sections, whereas the upper
spinning means causes the pipe sections to be screwed in, or unscrewed,
respectively. A similar concept is shown in U.S. Pat. No. 4,603,464.
Existing equipment is, obviously, limited as regards flexibility in case of
changed diameters or dimensions. A drill string may comprise drill pipes
having a diameter of 3,5" with a joint diameter of 4.5", and drill collars
with diameters up to 9.5". With existing equipment, it is common practice
to replace jaws in the gripping jaws of tongs at least once, perhaps
twice, to accomodate diameter variations. Also, many tools lack capacity
for the largest diameters.
SUMMARY OF THE INVENTION
According to the invention, a torque wrench is achieved which is flexible
as regards various pipe dimensions or pipe diameters, and it is able to
accomodate, e.g. the range from 3.5" drill pipes to 9.5" drill collars.
Additionally, it contributes to autocentering the pipes in the wrench
means. As distinct from previous concepts, the present torque wrench
adapts the clamping moment to the pipe diameter. Thus, the pipe joints are
spared, resulting in a longer life of the drill pipes. The structural
design of the torque wrenches ensures a self-tightening effect of the
jaws, resulting in a good and reliable frictional engagement between jaws
and drill pipes over all of the range of pipe dimensions. The device
according to the invention also permits a combination of the torque wrench
with a spinning means into one unit. Combined with back-up wrenches, and
mounted on a carriage, this will provide a less complicated build-up with
fewer parts and a lower weight for the complete roughneck.
With conventional separate spinning and torque wrenches equipment, the
components or units must be operated with the aid of separate control
levers. Since each unit has several functions, e.g. clamping, spinning,
opening spinning means, and closing, clamping, twisting, and opening
torque wrenches, the operator will have to execute a large number of
functions in each operation.
In a combined spinning and torque wrench, the number of functions to be
carried out by the operator is minimized, torque tightening being a direct
continuation of the spinning movement, and it will, consequently, be
possible to operate with one lever.
According to the invention, the above advantages are achieved by a torque
wrench of the kind mentioned above, comprising a split casing which may be
separated to enclose pipes. Each casing half comprises jaws which are
synchronously movable for centering and frictional engagement with the
pipe sections. The device is characterized by the fact that the wrenches
comprises a split internal annulus which is mounted in and connected with
a split intermediate annulus, which is rotatably mounted in said split
casing. The inner annulus is provided with at least two activable and
displaceable clamping jaws and means are provided and temporary and
external transmission of a controlled angular movement to the internediate
annulus. The angular movement, in turn, is transmitted to the inner
annulus by the aid of the aforementioned connection, the latter at the
same time activating and tightening the displaceable clamping jaws with
necessary force.
Advantageously, friction generating means are provided temporarily to
restrain any relative movement between the inner annulus and the casing.
The connection between the inner annulus and the intermediate annulus may
be achieved by the aid of at least one tangentially arranged and
tangentially acting pump cylinder. Each pump cylinder is, preferably,
hydraulic and in hydraulic communication with hydraulic radially acting
clamping jaws. The clamping jaws may suitably be provided in elongated
guiding cylinders to provide control and a firm grip of the jaws over the
whole range of pipe diameters. Each pump cylinder may advantageously be
double-acting and in connection with one hydraulic and two-directional
clamping jaw via respective hydraulic circuits.
The intermediate annulus may advantageously comprise means for an operative
connection with a spinner motor for controlled rotation of intermediate
annulus and the connected inner annulus in order to form a combined
spinning and torque wrench.
The wrench may suitably comprise a separate back-up wrench provided below
and, correspondingly, being intended for gripping pipes of various
dimensions, with one or both wrenches being substantially movable
vertically along guides.
The spinning and torque wrench and the back-up wrench means are preferably
provided on a carriage, with one or both tongs means being substantially
movable in a vertical direction along common guides provided on the
carriage to form a complete roughneck.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features, and advantages will appear from the following
disclosure of an embodiment of the invention which is at present preferred
and is described with reference to the attached drawings to illustrate the
invention.
In the drawings:
FIG. 1 is a diagrammatic top view of the torque tongs or wrench device
according to the invention,
FIG. 2 is a perspective view of the front portion of the torque tongs
device according to the invention,
FIG. 3 is a diagrammatic view of the mode of operation of the tongs device,
FIG. 4 is a diagrammatic view of a back-up tongs means, commonly mounted
below the torque tongs device,
FIG. 5 is a diagrammatic side elevation of a complete roughneck comprising
the torque tongs device, the spinning means, and the back-up tongs means,
FIG. 6 is a diagrammatic front view of the roughneck according to FIG. 5.
DETAILED DESCRIPTION
FIGS. 5 and 6 show a complete roughneck 1, with torque tongs device 2
forming a first device control unit, and with a back-up tongs means 3
forming another device control unit. Both tongs are mounted on a carriage
4 provided with wheels for displacement, e.g. on a drill rig floor 7.
Carriage 4 may be provided with wheels intended for moment on rails which
are, in turn, mounted on drill rig floor 7. Vertically extending guides 5
are mounted on carriage 4 for controlled independent movement of torque
tongs means 2, and back-up tongs means 3, respectively. As mentioned,
complete roughneck 1 is intended for joining, tightening, breaking out,
and unscrewing operations on pipe sections 6 by gripping sleeve and tap
members 8, respectively.
In a top view, in FIG. 1, the torque tongs device is shown in more detail.
The shown torque tongs device comprises a motor 25 for rotation of a
portion of the tongs means to screw together pipe joints. When the torque
tongs device is provided with such a spinning motor, it consitutes a
spinning and torque tongs device 3. The tongs means comprises a casing 10
which is split into two halves 10a, and 10b, respectively. Casing halves
10a, 10b can be locked together by the aid of a locking means 26 which is
provided on the front edge of casing 10. Casing 10 can be split along its
axis of division 50 so as to receive pipe sections in the tongs means.
Each casing half 10a, 10b is swingable or pivoted about a common shaft 24.
A fluid power cylinder 31 operates an opening and closing mechanism 25.
The shown torque tongs means is also provided with sleeve guides 32 for
slidable cooperation with guides 5 on carriage 4.
The rotatable portion of the torque tongs device is shown in more detail in
FIG. 2. The stationary portion of the tongs consists of casing halves 10a,
10b. The rotatable portions of the tongs device comprise an inner annulus
12, and an intermediate annulus 11. Intermediate annulus 11 is composed of
two halves 11a and 11b. Correspondingly, inner annulus 12 is composed of
two halves 12a and 12b. Inner annulus 12 is mounted in intermediate
annulus 11 by the aid of a bearing. Intermediate annulus 11 is, in turn,
mounted in casing 10. The bearings may be of any suitable kind, e.g. ball
bearings, roller bearings, and slide bearings. The bearings may be
removable, or they may form part of components. The bearing material may,
e.g., be sprayed directly onto the portions that are movable relative to
each other. It should be mentioned in this connection that movement
between inner annulus 12 and intermediate annulus 11 will only occur along
a small curved angular segment and will hardly create much wear. Essential
rotation and relative movement will occur between intermediate annulus 11
and casing 10.
In the shown embodiment, intermediate annulus 11 is provided with bolts
forming a tooth structure 16 for operative engagement with a gear 17 which
is arranged on spinning motor 25. Spinning motor 25 may be of any desired
kind, e.g. a hydraulic motor. Besides being mounted in intermediate
annulus 11 the inner annulus 12 is connected with intermediate annulus 11
via pump cylinders 15. Pump cylinders 15 may be pneumatic, but are,
preferably, hydraulic. Pump cylinders 15 are at one end connected with
intermediate annulus 11 by the aid of, e.g. pivots (not shown). At the
other end pump cylinders 15 are rotatably attached to inner annulus 12.
The piston rod of pump cylinder 15 is preferably, but not necessarily,
attached to intermediate annulus 11, and the casing of pump cylinder 15 is
pivotally connected with inner annulus 12. Inner annulus 12 also comprises
clamping cylinders 13 which are secured to inner annulus 12. Each inner
annulus half 12a and 12b must have at least one such clamping cylinder 13.
Even though the shown embodiment is provided with four clamping cylinders
13 any number of clamping cylinders from two upwards may be used. Clamping
cylinders 13 control activable and displaceable clamping jaws intended for
engagement with pipe joints. Pump cylinders 15 are connected with clamping
cylinders 13 via pneumatic or hydraulic circuits 20, which constitute
hoses in the shown embodiment. Instead of using hoses 20, channels may be
drilled in the inner annulus 12. It should be observed that the pneumatic
or hydraulic circuits are closed circuits; thus, there is no transmission
of fluid between casing 10 and intermediate annulus 11 or inner annulus
12.
As shown, casing 10 as well as inner annulus 12 and intermediate annulus 11
are divided and may be split to receive a drill pipe. When the tongs
device is to be split, intermediate annulus 11 and inner annulus 12 must,
consequently, be in such a position relative to casing 10 that their
respective division lines coincide with the division line or axis 50 of
the casing. As shown in FIG. 1, a positioning valve 28 is provided to be
activated mechanically, e.g. by projections on the intermediate and inner
annulus. Whenever intermediate annulus and inner annulus are not within
this area, the tongs cannot be split. In which casing half the respective
annulus halves are present is of no consequence, so that the maximum
rotation of rings 11,12 before they split is 180.degree.. On the face of
division between intermediate annulus halves 11a, 11b guides are
preferably provided, e.g. pin and aperture (not shown). Corresponding
guide pins and apertures may advantageously be provided on the faces of
division of inner annulus halves 12a and 12b, respectively. As shown in
the Figure, inner annulus 12 is also provided with recesses 18 for the
pivot between intermediate annulus 11 and pump cylinder 15 to permit
relative angular turning between intermediate annulus 11 and inner annulus
12.
A working cylinder 21 is mounted on casing 10 and intended to transmit the
turning moment to intermediate annulus 11 to be transmitted to inner
annulus 12. This working cylinder may be hydraulic, pneumatic, or
mechanical and will act as a linear motor. Piston rod 33 of working
cylinder 21 is rotatably connected with a displaceable casing 22, which is
slidably mounted in casing 10. When working cylinder 21 is activated,
sliding casing 22 describes a circular arch and will normally span a
sector of 30.degree.. Inside sliding casing 22, a pawl 23 is journalled in
a pivot 34. When working cylinder 22 is in a retracted position, i.e. when
piston rod 33 is totally retracted into working cylinder 21, pawl 23 is in
a "resting position". When cylinder 21 is activated, a mechanism will
cause pawl 23 to turn about pivot 34 until a nose member on the pawl
contacts the inside of sliding casing 22. At the same time, a hook member
36 on pawl 23 engages the bolt tooth means and will cause rotation of
inner annulus 11 when piston rod 33 is further extended, so that a moment
of rotation is transmitted to inner annulus 11. As soon as the piston rod
is retracted into working cylinder 21, e.g. a spring mechanism will turn
pawl 23 back into its starting position. If necessary, working cylinder 21
can make a plurality of strokes to achieve the necessary moment. In the
shown embodiment, pawl 23 acts on the same bolt tooth arrangement as
spinning motor 25. These transfers, however, may be separate and could be
achieved in a different manner, e.g. by the aid of a conventional gear
rim.
As shown in FIG. 1, the torque tongs means can, advantageously, also be
provided with a friction-generating means 30, e.g. corresponding to the
conventional disk brake. In the shown embodiment, a caliper casing is
secured to casing 10 of the torque tongs device, where activable
frictional linings are intended to cooperate with a braking disk (not
shown) that is secured to inner annulus 12. The function of friction means
30 will be disclosed in more detail below.
FIG. 3 shows a diagrammatical view of the torque tongs device which will
illustrate more clearly how the tongs device operates as well as its
performance. Split inner annulus 12 is provided with four cylinders 13,
each receiving a clamping jaw. Clamping jaws 14 are movable in cylinders
13 and provide a tongs device which is flexible as regards the dimensions
of drill pipes. Normally, the tongs device may be used for pipe dimensions
from 3.5" drill pipe to 9.5" drill collar. However, this range may be
enlarged without special difficulties. Each cylinder 13 is connected with
a pump cylinder 15, via a hydraulic circuit. Between inner annulus 12 and
intermediate annulus 11, a slight relative angular movement is possible.
When a pipe section 6 is gripped by the torque tongs device, brake means
30 is activated to hold inner annulus 12 temporarily. Then, intermediate
annulus 11 is turned; the turning moment is, in turn, transmitted, via
piston rods in pump cylinders 15, to activate the inner and closed
hydraulic circuit. Thus, the pressure is transmitted to cylinders 13 and
clamping jaws 14. The clamping jaws are displaced radially towards drill
pipe 6 to center the pipe. In the Figure, four separate independent
hydraulic circuits are shown, but in other embodiments one single pump
cylinder 15 may activate two or all jaws in an inner annulus half 12a,
12b. Now, brake means 30 is released, and motor 25 spins intermediate
annulus 11, inner annulus 12 with jaws 14, and the pipe section 6 as one
single unit into a lower socket joint end 8 of a pipe section. When the
pin end of the joint is spun into the socket of sleeve portion of the
joint by the aid of spinning motor 25, which commonly contributes with a
tightening moment in the order of 7 kNm, the final moment is made up by
pressure in working cylinder 21 which is transmitted to inner annulus 11,
via pawl 23. The pressure applied to working cylinder 21 has to be
adjusted in accordance with the pipe diameter present in the tongs device.
The geometry of the connection between inner annulus 11 and intermediate
annulus 12 should be noted. The connection is provided by pump cylinders
15. The line of action of cylinders 15 is especially notable. In case of
large pipe, diameters, the lines of action of pump cylinders 15 will be
tangential with relative large circles about the centre of pipe. In case
of smaller pipe dimensions the line of action of cylinder 18 will be
tangential with circles about the centre of pipe of smaller diameters, or,
as shown in the Figure, pump cylinders 15 will move into a more radial
position. As known, various tighteningmoments are required for various
pipe dimensions, with the largest pipe dimensions requiring the largest
tightening moment. It is, e.g., common to tighten conventional 3.5" drill
pipes by 10 kNm, and large drill collars of 9.5" by 120-150 kNm. The shown
concept permits the operator to adjust the clamping force of jaws 14 in a
comparatively simple manner by the aid of the pressure applied to working
cylinder 21. The geometry of the structure, indeed, ensures that the
necessary force is achieved. In case of small pipe dimensions, the line of
action of pump cylinders 15 is more radial, which would, in case of a
constant turning moment of intermediate annulus 11, cause considerably
higher radial forces in clamping jaws 14 than in case of large pipe
dimensions. However, small pipe dimensions do in fact require a lower
tightening moment and, consequently, working cylinder 21 should apply a
lower turning moment to inner annulus 11. This lower turning moment, in
turn, will cause a lower pressure in the inner circuits 20.
Correspondingly, pressure in jaws 14 will decrease in case of increasing
pipe diameters since pump cylinders 15 move to a tangential position in
increasing circles about the pipe centre. This is compensated for by an
increased pressure applied to working cylinder 21 so as to provide for a
sufficient turning moment on intermediate annulus 11 and, consequently, an
tightening torque to pipe joint 8. According to the above described
process, the tightening moment may readily be adapted to various pipe
dimensions, and that goes for clamping forces applied by jaws 14 to pipe
joint 8 as well. Thus, the working surfaces of the pipe joints are spared
in a much better manner than was previously possible.
FIG. 4 is a diagrammatic view of a back-up tongs means which, indeed, can
be of any suitable known kind, but is, advantageously of a flexible
dimension kind. The shown tongs means is of a kind having a constant
opening and is, thus, not a split kind. Three cylinders with associated
clamping jaws are shown, but any suitable number of cylinders may be used.
The back-up tongs means is vertically movable in relation to the torque
tongs device, preferably along the same guides 5 as used by torque tongs
device 2.
Each cylinder 13 holding and guiding the clamping jaws 14 is of a kind
known per se and therefore is not disclosed in detail. It should, however,
be mentioned that they are of a certain length to be flexible in relation
to the intended range of dimensions, at the same time as they ensure good
lateral support and guidance within their entire operative range of
movement.
* * * * *
|
|
|
|
|
|
|
Description |
|
