Note: Descriptions are shown in the official language in which they were submitted.
CA 02329398 2000-12-21
r
~ ' 2580DE
Pusher apparatus for pipes and pipe strings
Description
The invention relates to a pusher apparatus~for drill
strings and pipes (tubes, joints, casings) in drilling
installations with top drives which are used for bores
which are normally sunk during crude-oil and natural-gas
exploration and production.
In particular, such pusher apparatuses of the generic
type are used in so-called snubbing units (units for
running drill strings and pipes in and out) or are
combined with conventional drilling installations and
serve as a running-in aid for the well casing.
In principle, pusher apparatuses (e. g. casing push
tools) may be used wherever pipes and drill strings have
to be pushed into a well. This takes place wherever a high
resistance in the well is to be overcome. For example, in
side-tracked bores, the weight of the pipes or drill rods
which are run into the well via the side tracking is often
insufficient in order to overcome the sliding resistance
of the pipes or drill string at the well wall in
horizontal or side-tracked sections of the bore.
Furthermore, a pusher apparatus is always required when
the mud or formation pressure is greater than the weight
of the string or the pipes.
US specification 1,972,635 discloses a drilling
outfit with which the control for the sucker rods in oil
- CA 02329398 2000-12-21
- 2 - 2580DE
and gas bores can be improved, in particular if the bore
isun-der~.pressure during the drilling and if running-in and .
running-out work is to be carried out.
In order to be able to achieve this obj.ect,.- a
snubbing apparatus is firmly connected to-the drill rod to
be run into the well, this apparatus consisting of a
frame, in the center of which an opening is provided,
through which opening the drill rod is guided. The drill
rod is firmly connected to the frame by means of clamping
and gripping devices.
A rope end is fastened in each case to two outer
sides of the frame, this rope end being suspended in the
drilling hook of a pulley block via deflection pulleys
firmly connected to the working platform of the drilling
installation.
If the drill rod is to be pushed into the well, the
drilling hook is pulled upward by means of the pulley
block, so that the force via the deflection pulleys pushes
the frame of the snubbing apparatus and thus the drill rod
downward.
A disadvantage of this drilling outfit is that each
individual drill rod has to be firmly connected to the
frame in an elaborate manner, in which case the risk of
the drill rod slipping through is very high if the
clamping or gripping pressure of the clamping or gripping
device is inadequate. In addition, the effective force of
the snubbing apparatus is limited by the winch-rope
pulling force of the winch driving the pulley block.
CA 02329398 2000-12-21
- 3 - 2580DE
'Furthermore, only drill rods of limited. length can be.
pushed in. .
The object of the present invention is ~to specify a
pusher apparatus for drilling installations with top
.drive, with which pusher apparatus additional forces can
be~ provided in order to push drill strings or pipes or
stands of drill pipes into the well.
The object is achieved by the features of claim 1.
Further advantageous refinements of the invention are
specified in the subclaims.
The pusher apparatus according to the invention for
drilling installations with top drive consists of a force-
transmission arm which is displaceable on a guide, is
connected to a pulling device and is provided with a
guide, the guide being arranged axially relative to the
top-drive guide.
The pusher apparatus according to the invention has
the advantage that a pressure force can be applied to the
drill strings or pipes which have to be run into wells if
the dead weight of the drill strings or pipes, such as the
well casing for example, and the pressure force or the
weight of the top drive are no longer sufficient in order
to enable said drill strings or pipes to be run into the
well. It is also possik~le by means of the arrangement
according to the invention to run entire stands of drill
pipe (double or triple stands) into the well, since the
force-transmission arm can also be moved well to the top
on the guide of the top drive. As a result, the time-
CA 02329398 2000-12-21
- 4 - ~ 2580DE
consuming addition of individual drill rods to the drill
string is dispensed with. ~ ~ . ..
In'an advantageous refinement of the invention, the
pusher apparatus according to the invention is
distinguished by the fact that a transition element is
arranged between top drive and force-transmission arm.
This transition element, which is preferably between 20
and 250 centimeters in length, forms a parallelogram of
forces with the top-drive guide in order to absorb the
buckling forces.
The pulling device of the pusher apparatus preferably
consists of a drum winch, a deflection pulley, a rope, a
drive and a control. This advantageous pulling device is
cost-effective and simple to manipulate.
In a preferred variant of the pusher apparatus, the
deflection pulley is arranged on a base frame, so that the
rotary table can be bridged and at the same time it is
ensured that the forces which occur are introduced
uniformly into the foundation of the steel structure.
A pusher apparatus which is connected by means of a
supporting device to a working platform or a base frame of
the pulling device is especially advantageous. Thus high
loads which the top-drive guide and the extension piece
are exposed to due to the resulting pulling forces and
torques during operation of the push-in aid can be
directed into the foundation of the steel structure.
Buckling or twisting of the guide rails is prevented.
CA 02329398 2000-12-21
- 5 - 2580DE
The push-in head preferably. arranged on the .force-
transmission arm is interchangeable,. so that the 'push-in
aid can be used for, different pipe arid drill-string sizes
or diameters. A design variant provides for the push-in
head to have a conical profihe on its side facing the
drill string or pipe, so that the pipe or drill string can
be caught and a push-in head for several pipe diameters
can be utilized. If required, a circulation head may also
be used in order to be able to introduce the mud into the
well at the same time.
The guide for the force-transmission arm preferably
consists of a guide shoe which is vertically movable on at
least one guide rail arranged on the inside or outside on
the top-drive guide or an extension piece extending the
top-drive guide. This advantageous refinement is cost-
effective and is not prone to breakdowns.
A further refinement of the invention provides for
the guide shoe to be connected to the guide of the top
drive preferably by means of a rope or a pipe in order to
reduce those loads, in particular, on the top-drive guide
and on the extension piece which occur due to the pulling
forces.
The drum winch of the pulling device is preferably
driven hydraulically or electrically and has a rope
pulling force up to 25 tonnes.
An exemplary embodiment is explained in more detail
with reference to figures 1 to 3.
Fig. 1 shows the pusher apparatus in side view,
CA 02329398 2000-12-21
6.- 2580DE
Fig. 2 shows the pusher apparatus i1~ front view .in
. combination with part of a drilling installation
and a .top drive,
Fig. 3 shows a plan view of a drilling installation.
The pusher apparatus is shown inside view in fig, l,
in which case the existing guide 3 of the top. drive 2 has
been extended by an extension piece 12 of the guide . This
ensures in a special manner that the tubes 8 or stands of
drill pipe or drill rods to be run in can be pushed into
the well until just above the working platform by means of
the winch 23 arranged on the working platform 5. The winch
may be driven both electrically and hydraulically. As on
the top-drive guide 3, guide or sliding rails 11, on which
the guide shoe 10 is moved and guided, are arranged in the
extension piece 12. However, in a special design which is
not shown, the guide shoe 10 may also be guided in the
guide rail 11 by means of rollers which may be arranged so
as to point both inward (for example for monorails) and
outward (e. g. for double rails).
The guide shoe 10 may be moved up and down on these
rails 11 like a slide. It may also be guided in an
especially advantageous manner on the guide rails 11 of
the top-drive guide, so that not only individual rods or
pipes can be run into the well, but stands of two or three
pipes or drill rods can be run into the well in one
operation.
Arranged on the guide shoe 10 is a force-transmission
arm 14, which is advantageously connected in this
CA 02329398 2000-12-21
- ~ - 2580DE
exemplary embodiment to the guide shoe 10 by bolts 13. As
a result, it is advantageously possible. to remove the
force-transmission arm from the guide shoe ~.0 in a very
easy and simple operation. Instead of a screwed
connection, the connection between guide shoe 10 and
force-transmission arm 14 may also be produced by a
clamping or push-in connection. If removal should not be
desired, the guide shoe 10 and force-transmission arm 14
could also be designed as a unit. A connection (not shown)
between guide shoe 10 and top-drive-guide slide 7 has also
proved to be advantageous. The connection may be made by
means of a rope or pipe.
The force-transmission arm 14 serves to accommodate a
push-in head 18, which can be exchanged by simply being
lifted out or pushed out in order to be able to run in
different pipe sizes by means of the push-in head 18
matched to the pipe diameter. The push-in heads 18 used
are preferably those with a conical plastic insert, or
circulation heads through which the mud can be introduced
into the well in order to be able to reduce the requisite
push-in force. The push-in heads 18 may be connected to
the force-transmission arm 14 in a frictional manner, for
example with bolts, screws, push-in connections or other
releasable connections.
A pulling lug 19 for a wire rope 22 is welded to the
force-transmission arm 14 in order to transmit the
pressure force to the pipe (not shown) to be run in by
means of the pulling force in the wire rope, this pulling
CA 02329398 2000-12-21
- 8 - 2580DE
force being produced by the winch (not shown here). The
. connection between the wire rope 22 and the force-
transmission arm 14 may also be made in another manner.
However, the wire rope 22 preferably starts as 'close to
the guide shoe 10 as possible.
The pulling lug 19 may also be mounted on the force-
transmission arm 14 in another form of connection, such
as, for example, by positive locking (screwed connections)
or friction grip (clamping connections).
Also shown is the deflection pulley 21, which is
connected to a deflection-pulley base frame 20. The
deflection pulley 21 may be screwed, pinned or welded to
the frame.
A transition element 17 serves as connecting piece
between the bottom region of the top drive 2 (not shown)
and the force-transmission arm 14. The transition element
17 is preferably made of steel and has a thread at its top
end, so that the transition element 17 can be screwed to
the top drive 2. At its bottom end, the transition element
17, when circulation heads are used, has a thread whose
diameter corresponds to that of the pipe to be pushed in.
When normal push-in heads are used, no thread is provided.
In a special manner, this arrangement has the advantage
that the length of the guide shoe 10 can be kept short,
since the buckling behavior in the extension piece 12,
which in this case extends the top-drive-guide rails, is
reduced to a minimum by this transition element 17. The
CA 02329398 2000-12-21
- 9 - . 2580DE
transition element 17 preferably has a length of between
20 and 250 cm.
In this exemplary embodiment, a support- 16 is
advantageously arranged between the extensiori~ piece 12 and
the deflection-pulley base frame 20, in this.case by means
of a bolt connection via a connecting element 15. The base
frame 20 is firmly connected to a working platform 5. The
torques which result from the pulling force can be
introduced into the working platform via this support 16.
In a special design, the connections between guide shoe
10, support 16 and deflection-pulley base frame 21 may
also be made by means of frictional or integral
connection.
The push-in apparatus is shown in front view in fig.
2 in combination with an existing steel structure 1 (a
mast or a derrick) . The steel structure 1 in this case is
a drilling rig. Shown in this figure is a top drive 2,
which is guided in a top-drive guide 3, which is firmly
connected to the drilling rig 1. Located below the top-
drive guide 3 is the extension piece 12 (not shown) which
extends the guide rails of the top drive. The extension
piece 12 is coupled to the top-drive guide 3 by means of a
releasable connection (not shown). This makes it possible
to install the pusher apparatus only when it is required.
The tubular transition element 17 is located between the
top drive 2 and the push-in head 18, which is pushed into
place in the force-transmission arm 14. Located below the
push-in head 18 is a pipe 8 which is to be pushed in. The
CA 02329398 2000-12-21
- 10 - 2584DE
pipe 8 is held by the holding apparatuses of the elevator
6, which is arranged under the top drive 2, during the
transfer from or delivery to the drill-string handling
device (not shown) . The strap of the elevator 6 spans .the
length of the- transition element 17 and. of the push-in
head 18.
Fig. 3 shows a possible arrangement of the push-in
apparatus on a working platform 5 and the arrangement of
the drum winch 23 standing slightly to one side and also
the hydraulic unit 24 connected to the drum winch via the
hydraulic line 25. In this representation, the drum winch
23 is arranged in a 45° position relative to the axis of
the well/top-drive guide (AA'). However, any other
position of the winch 23 both above and below the working
platform 5 is also conceivable . The winch 23 is used as a
pulling device in order to exert the requisite force on
the pipes or drill rods to be run in via the force-
transmission arm 14 (not shown). However, other pulling
devices are also conceivable.
It is also possible to install a winch 23 on the
steel structure, in this case the drilling rig 1, in order
to keep the region of the working platform clear. The
deflection pulley 21, which is likewise shown in this
figure, is located on the working platform 5 at
approximately the same angle as the winch 23 approximately
below the top-drive guide 3 or the extension piece 12.
The winding rope 22 is arranged on the drum of the
winch 23 in an underwinding configuration and runs
CA 02329398 2000-12-21
-.11 - 2580DE
horizontally from there in the direction of the deflection
pulley 21, which is located in front of. the draww works
directly next to the rotary .table.- The deflection pulley
21 may be arranged above or below. the working platform,
but it may. always be arranged in ~an .appropriate manner
below the top-drive guide.
In this exemplary embodiment, the deflection pulley
21 is fastened to a base frame 20. The latter primarily
serves to introduce the forces which act on the deflection
pulley 21 into the foundation of the steel structure 1. At
the deflection pulley 21, the rope is deflected by about
90° from the horizontal into the vertical and is fastened
to the force-transmission arm 14. With a remote control
26, the crew are able to run, control and monitor the drum
winch 23, which in this case is hydraulic.
In its top region, the guide shoe 10 is guided in the
top position on the top-drive-guide rails 3. The guide
shoe 10 serves as a guide and abutment for the force-
transmission arm 14. The extension 12 is arranged on the
top-drive guide 3 in particular when the pipes are to be
pushed into the well down to a few centimeters above the
working platform 5.
A connection between the top-drive guide 3 or the
extension piece 12 and the base frame 20 or the working
platform 5 is created by the fitting of the support 16, so
that the buckling of the guide rail under load, in
particular when lateral pressures or lateral pull occurs,
can be prevented.
CA 02329398 2000-12-21
- 12 - 2580DE
Pipes having diameters. of 5~.to 7".and drill rods
having a diameter of 5" can preferably be gushed in.
CA 02329398 2000-12-21
- 13 - 2580DE
List of reference numerals used
1 Steel s.tructure/drilling rig
~2 Top drive
3 Top-drive guide
4 Connection between top-drive guide (3) and extension
piece ( 12 )
S Working platform
6 Elevator
7 Top-drive-guide slide
8 Drill string/pipe
9 Stanchions of the steel structure (1)
Guide shoe
11 Sliding rails = guide rails
12 Extension piece, removable
13 Fastening
14 Force-transmission arm
Connecting element
16 Support
17 Transition element
18 Push-in head
19 Pulling lug
Base frame for deflection pulley (21)
21 Deflection pulley
22 Winch rope
23 Drum winch
24 Hydraulic unit
Lines
CA 02329398 2000-12-21
- 14 - 2580DE
26 Remote control
27 Foundation of drum winch (23)
