Note: Descriptions are shown in the official language in which they were submitted.
CA 02925247 2016-03-23
,
1
Title: A DEVICE FOR CONTROLLING A BRAKE OF A DRUM
OF A DRAW-WORKS EQUIPPING A DRILLING RIG, AND A METHOD
OF CONTROLLING SUCH A DEVICE
(57) Abstract: A device (40) for controlling a
brake of a drum of a draw-works (2) equipping a
drilling rig operating a drill tool in a borehole,
which device comprises a brake lever (24) having a
first end (29) connected mechanically to brake bands
designed to act on the drum and a second end (30)
provided with a first brake control handle (31). The
device (40) further comprises actuation means (32)
configured to be controlled and arranged to act
mechanically on the brake lever, and a second brake
control handle (33) arranged to servo-control said
actuation means.
"A device for controlling a brake of a drum of a
draw-works equipping a drilling rig, and a method of
controlling such a device"
Field of the invention
The present invention relates to a device and a
method for controlling a brake for a drilling rig, and
to an automatic drilling system implementing such a
device.
The invention relates more particularly to the
field of petroleum drilling of the "rotary table" type
CA 02925247 2016-03-23
,
,
,
2
and/or of the "top drive" type. A "rotary table" system
usually includes an injection head, a pull rod or kelly
that passes through a rotary table and that is
connected to a string of drill-pipes or "drill string",
and, at the end of the string, a drill tool or "drill
bit" that cuts into the ground. The kelly, and
therefore the drill string and the drill tool at the
end of the string are all subjected to rotation via the
rotary table and via an angular section of the string
that is situated at the table, or, if the table does
flot constitute the means for rotating the drilling
machinery, via the injection head that also serves to
drive the string. The invention could also be applied
to the field of geothermal drilling.
State of the prior art
On a drilling rig, the drill string, which, at
its bottom end, is provided with the drill tool, is
hooked onto a drill hook, movement of which is
controlled by a drilling draw-works or winch. The
drilling draw-works includes a brake for preventing the
cable from unwinding from the draw-works in untimely
manner. The operator or "driller" uses a device
referred to as a "brake control" for controlling loads
or tools lowered into the borehole or "well". The brake
control thus makes it possible to control the speed and
deceleration of the drill hook, optionally to the
extent of stopping it from moving.
CA 02925247 2016-03-23
,
,
'
,
3
On a majority of drilling rigs, the brake is a
mechanical brake having bands. Such a brake is made up
of two metal bands equipped with internai linings
fastened by flush-head or "countersunk-head" copper or
aluminum bolts. Those bands are connected together by a
balancing bar that also distributes the braking force
between the two bands, thereby reducing the wear on the
brake shoes or "brake pads". Each band wraps around a
respective rim constrained to rotate with the drum. One
end of each band is stationary, while the other end is
connected via a set of cams and connection rods to a
hinged lever (the brake control), thereby making it
possible to gear down the force to be exerted on its
end.
On other drilling rigs, the brake is a disk
brake. In which case, the brake control is implemented
in the form of a joystick.
Whether it be via use of a brake control in the
form of a hinged lever or "brake lever", or in the form
of a disk brake, manual control of the brake control by
the driller can give rise to lack of accuracy in
actuation of the brake control, which can lead to
under-efficiency of the progress of the drilling and to
premature wear on the drill tool. An error by the
driller can lead to the drill tool being destroyed, or
to the well being lost.
Since the constitution of the ground varies over
any given drilling stage, manual control of a brake
CA 132925247 21316-03-23
4
control requires constant attention, which, for
example, constitutes a safety problem due to the human
factor. An object of the invention is thus to propose a
device and a system, as well as a method, for
automating the brake control.
Document US 4,187,546 discloses a drum brake
including a primary brake whose function is to control
the speed and the deceleration of a traveling block of
the draw-works, and to stop it from moving. That
primary brake is a drum brake that can be actuated
manually via a brake control. In addition, that
document discloses a return spring that urges the drum
brake back into the braking position. That document
teaches that the spring can be overridden manually so
as to release the brake. It discloses that the lever
may be connected to a brake actuator comprising a
cylinder provided with a piston. Injecting fluid into
the cylinder moves the piston, thereby causing the
brake control to move to modulate the force on the
brake. The force exerted by the piston on the brake
control must exceed the return force of the spring.
Emergency braking takes place by emptying the fluid
contained in the cylinder into the atmosphere, thereby
causing the piston to descend into the cylinder and
then the brake control to be urged back by the return
spring. It should be noted that such emptying of the
fluid contained in the cylinder can give rise to risks
of pollution and can be toxic.
CA 02925247 2016-03-23
,
,
Document EP 0 694 114 also discloses a primary
brake in the form of a band brake that is, a priori,
manually actuatable by a brake control. That document
discloses an additional return spring that urges the
5 band brake into the braking position and that can be
overridden manually for releasing the brake. The lever
may be connected to a brake actuator assembly. More
precisely that brake actuator assembly comprises a lift
unit connected to a lift une or cable for pulling on
the end of the brake control to modulate the force on
the brake. Thus, the function of the lift unit is to
oppose the return force of the spring and thus to allow
the drilling draw-works to descend. For this purpose,
the force exerted by the lift unit on the brake control
must exceed the return force exerted by the spring on
the brake control.
A first drawback with such brake devices is that
they have reactivity characteristics that are difficult
to make compatible with the numerous variations in the
ground that can require very quick reactions, such as
when drilling through an influx or encroachment of
fluid in the borehole requiring almost instantaneous
stopping. In addition, if the spring breaks, the drill
hook and its load descend unbraked, with disaster
ensuing.
Another drawback with such devices is that the
additional spring is dimensioned to exert a return
force that is sufficient to withstand the maximum
weight that is implemented when the drilling is at its
CA 02925247 2016-03-23
6
deepest possible. This implies that the largest force
for countering that return force and for allowing the
brake to descend is implemented at the start of
drilling. That implies forces that are very high in the
early stages of drilling. The deeper the borehole and
the drilling become, the lower the force necessary for
releasing the brake. That can give rise to safety
problems for very deep drilling.
Another drawback with such devices is that they
require the brake control to be equipped with more than
one instrument. Unfortunately, a control cabin for a
driller is often a very confined space. An object of
the invention is thus to propose a device that is more
compact than the prior art devices. Another object of
the invention is to propose a brake actuator device
that is faster, more accurate, and safer during braking
and more particularly during emergency braking.
Another problem-solving object of the invention
is to install a device that is transparent when used by
the site manager, i.e. that requires less learning by
the site manager about how the device operates. Another
problem-solving object of the invention is to propose a
device arranged to operate in co-operation with the
driller.
Summary of the invention
The invention makes it possible to achieve at
least one of the objects by providing a device for
CA 02925247 2016-03-23
7
controlling a brake of a drum of a draw-works equipping
a drilling rig operating a drill tool in a borehole,
which device comprises a brake lever having a first end
connected mechanically to brake bands designed to act
on the drum and a second end provided with a first
brake control handle. The brake lever may be
implemented in the form of a hinged lever.
In accordance with the invention, the device
further comprises actuation means configured to be
controlled and arranged to act mechanically on the
brake lever, and a second brake control handle arranged
to servo-control the actuation means.
The phrase "acting mechanically on the brake
lever" is used to mean acting actively rather than
passively on the brake lever, in the direction
corresponding to the brake bands being used to brake
the drum. Thus, the mechanical action on the brake
lever exerted by the brake control device is net of the
same nature as the mechanical action exerted by a
spring. The mechanical action of a spring on the brake
lever is passive, because it depends only on the
elongation and on the stiffness of the spring.
In accordance with the invention, the mechanical
action exerted by the brake control device is active.
Thus, the actuation means are arranged to act
actively on the brake lever at least se that the brake
bands partially prevent the drum from rotating.
CA 02925247 2016-03-23
8
Preferably, the actuation means are arranged to act
actively on the brake lever at least so that the brake
bands fully or partially prevent rotation of the drum.
Preferably, the actuation means are arranged to
act actively on the brake lever so that the brake bands
partially prevent and/or allow rotation of the drum.
Preferably, the actuation means are arranged to act
actively on the brake lever so that the brake bands
fully or partially prevent and/or allow rotation of the
drum.
The actuation means are configured to be
controlled to act on the brake lever at least in the
direction corresponding to the brake bands being used
to brake the drum. Thus, the mechanical action on the
brake lever exerted by the brake control device is not
of the same nature as the mechanical action exerted by
a spring. The mechanical action of a spring on the
brake lever is flot controlled, because it depends only
on the elongation and on the stiffness of the spring.
Thus, the actuation means are controlled to act
in accordance with a command on the brake lever at
least so that the brake bands partially prevent the
drum from rotating. Preferably, the actuation means are
arranged to act in accordance with a command on the
brake lever at least so that the brake bands fully or
partially prevent rotation of the drum.
CA 02925247 2016-03-23
9
Preferably, the actuation means are arranged to
act in accordance with a command on the brake lever so
that the brake bands fully or partially prevent and/or
allow rotation of the drum. Even more preferably, the
actuation means are arranged to act in accordance with
a command on the brake lever so that the brake bands
fully or partially prevent and/or allow rotation of the
drum.
Preferably, the actuation means are arranged to
act on the brake control lever in symmetrical manner,
i.e. they are suitable for delivering one action in the
braking direction in which the brake bands brake and a
symmetrical action in the releasing direction in which
the brake bands are released.
The actuation means thus procure automatic
control of the brake control device. The actuation
means thus procure automatic control of the brake
lever. The second control handle may be sensitive, i.e.
it may being provided with a sensitive sensor.
Alternatively or in addition, the control device may be
provided with a strain sensor for measuring strain on
the second control handle. Said strain sensor may, for
example, be implemented by a strain gauge.
Advantageously, the control device may further
comprise electronic means configured to control the
actuation means, on the basis of a control signal
emitted by the second brake control handle and/or of
information on weight conditions to which the drill
CA 02925247 2016-03-23
,
tool is subjected. The information on the weight
conditions to which the drill tool is subjected may be
replaced or supplemented with information on conditions
of differential mud pressure at the tool, and/or on
5 conditions of maximum torque in rotation withstood by
the drill tool, and/or on conditions of maximum speed
of penetration into the ground, and/or on operating
conditions of the draw-works. An operating condition of
the draw-works is, for example, the instantaneous speed
10 of rotation of the draw-works.
In other words, the second control handle is
configured to emit a signal referred to as the "handle
control signal".
In more advantageous manner, the second control
handle may be provided with and/or incorporate an
extensometer sensor arranged to generate a handle
control signal sensitive to the pressure exerted on the
second handle by the hand of an operator.
Alternatively or in addition, the second control
handle may be provided with a strain sensor arranged to
generate a handle control signal that is sensitive to a
force exerted on the second handle by the hand of the
operator.
The hand of an operator may advantageously be
replaced by any article arranged to exert a force
and/or a pressure on the second control handle. For
CA 02925247 2016-03-23
11
example, such an article may be a remotely controlled
actuator.
Preferably, the electronic control means are
arranged to servo-control the actuation means to a
setpoint thrust force in a braking mode. The braking
mode is naturally defined as an operating mode of the
device of the invention in which mode the brake bands
acting on the drum exert a braking force. In this
embodiment, the device of the invention partially
prevents rotation of the drum. The braking force may be
such that rotation of the drum is stopped.
Advantageously, the electronic control means may
also be arranged to servo-control the actuation means
to a setpoint position of the brake lever.
Advantageously, the electronic control means may
also be arranged to servo-control the actuation means
to a setpoint speed of movement of a predefined point
of the brake lever. Speed servo-control enables the
operator to feel sensations close to those felt under
manual drilling conditions.
Preferably, the actuation means are powered via
an uninterruptible power supply including power supply
interruption detection means, the electronic means
being configured to control the actuation means to
actuate them in the braking direction when a power
supply interruption is detected by the power supply
interruption detection means. The braking direction is
CA 02925247 2016-03-23
12
naturally the direction in which the device of the
invention partially prevents rotation of the drum.
Preferably, some or ail of the various means of
the invention are arranged to operate fully
electrically. Thus, for example and preferably, the
actuation means are controlled electrically rather than
pneumatically.
Preferably, the actuation means are arranged so
that, when the brake lever is in a given position, the
braking force applied by said actuation means increases
when the force exerted by the drill tool on the cable
wound on the draw-works increases.
Preferably, the actuation means comprise an
electric actuator.
Advantageously, the actuation means may comprise
a torque motor.
In another aspect of the invention, it provides a
method of controlling a brake control for controlling a
brake of a drum of a draw-works equipping a drilling
rig operating a drill tool in a borehole, which method
implements a brake control of the invention comprising
a brake lever having a first end connected mechanically
to brake bands designed to act on the drum and a second
end provided with a first brake control handle, said
method being characterized in that it comprises
applying a mechanical force to the brake lever, the
applied force being controlled to procure servo-control
CA 02925247 2016-03-23
=
13
of the position of the brake lever and/or of a thrust
force exerted on the brake lever.
Advantageously, the method of the invention
further comprises generating a control signal for
servo-controlling the position and/or the thrust force,
on the basis of a second control handle disposed
substantially at the second end of the brake lever. In
addition or alternatively, the servo-control of the
control lever may be implemented to servo-control the
speed of movement of a predefined point of the brake
lever. Speed servo-control enables the operator to feel
sensations close to those felt under manual drilling
conditions.
Preferably, the servo-control of the brake lever
is procured by an actuator controlled from an
electronic control unit arranged to process the control
signal generated on the basis of the second control
handle and/or of the information relating to the
operating conditions of the draw-works.
Advantageously, the information processed by the
electronic control unit may comprise information
relating to the weight applied to the drill tool.
Advantageously, the information processed by the
electronic control unit may comprise information on the
differential mud pressure at the drill tool.
CA 02925247 2016-03-23
=
=
14
Advantageously, the information processed by the
electronic control unit may comprise information on the
maximum torque in rotation withstood by the drill tool.
Advantageously, the information processed by the
electronic control unit may comprise information on the
maximum speed of penetration of the drill tool into the
ground.
Description of the figures and of embodiments
Other advantages and features of the invention
appear on reading the following detailed description of
embodiments and implementations that are in no way
limiting, and on observing the following accompanying
drawings:
¨ Figure 1 is a diagrammatic view of a drilling
rig of the "rotary table" type;
¨ Figure 2 is a diagrammatic view of a lever and
of a draw-works used on the drilling rig, seen looking
along a longitudinal axis;
¨ Figure 3 is a diagrammatic view of the draw-
works, seen looking along a vertical axis;
¨ Figure 4 is a diagrammatic view of a portion
of a brake control device of the invention; and
¨ Figure 5 is a diagrammatic view of a portion
of the brake control device of the invention.
CA 02925247 2016-03-23
,
Since these embodiments are in no way limiting,
it is possible, in particular, to consider variants of
the invention that have only a selection of
characteristics described below that are isolated from
5 the other characteristics described (even if the
selection is isolated within a sentence including said
other characteristics), if the selection of
characteristics is sufficient to impart a technical
advantage or to distinguish the invention from the
10 prior art. The selection includes at least one
preferably functional characteristic without structural
details, or with only a fraction of the structural
details if that faction is sufficient to impart a
technical advantage or to distinguish the invention
15 from the prior art.
In the figures, an element appearing in more than
one figure is given the same reference in every figure
in which it appears.
Figure 1 shows a drilling rig that is a metal
tower having a height of about thirty meters and that
serves to insert the drill bits.
This drilling rig 1 includes a derrick D making
it possible, via a block system and via a drilling
draw-works 2, to perform operations for replacing worn
borebits 3, for example, for replacing a string of
drillpipes or "drill string" 4 over a certain height,
and for storing the drill string element-by-element.
CA 02925247 2016-03-23
16
The block system is constituted by a crown block
that is mounted ta be stationary on the small base of
the derrick D, by a traveling block 6, and by a cable
C. The crown block 5, i.e. the stationary block, is
5 made up of a certain number of pulleys, ah l of which
are on the same axis. The traveling block 6, i.e. the
moving block, has one less pulley than the crown block
5. The traveling block 6 is balanced in such a manner
as ta make high descent speeds possible. A hoist hook 7
is suspended from the loop 6' of the traveling block 6.
The hoist hook 7 can swing freely about a horizontal
fixed pin ta which the arm of the suspension loop cames
ta fit.
The drilling rig 1 has a mud injection head 8,
and a pull rad or "kelly" 9. The kelly 9 passes through
a rotary table 10 and is connected ta the drill string
4.
At the end of the string, the drill tool 3 cuts
into the ground. The drill tool 3 may also be referred
ta as the "bit" or as the "borebit". It is the drill
collars, screwed on above the drill tool, that bear
down on it; these drill collars, extended ta the
surface by pipes, constitute the drill string or string
of drill-pipes 4. The drill collars are pipes that are
heavy and that are stronger than the pipes making up
the remainder of the drill string 4. They are placed
directly above the borebit 3. Their purpose is ta press
the drill tool 3 against the bottom of the borehole or
well P, and ta prevent the ordinary pipes from being
CA 02925247 2016-03-23
=
17
subjected to compression during the drilling work,
because they are much weaker and therefore much less
capable of withstanding massive flexion and traction
forces, thereby limiting the risks of breakage and
reducing the friction on the walls of the borehole P.
The pull rod or kelly 9, and therefore the drill
string 4 and the tool 3 at the end of the string, are
subjected to rotation via the rotary table 10 and via
an angular section of the string that is situated at
the rotary table 10.
In another embodiment, if the rotary table 10 is
flot the means for rotating the drilling machinery, the
kelly 9, and therefore the drill string 4 and the drill
tool 3 at the end of the string, are subjected to
rotation via the injection head 8 that also serves to
drive the string 4.
The drill string 4, which, at its bottom end, is
provided with the drill tool 3, is hooked onto the
hoist hook 7, movement of which is controlled by the
drilling draw-works 2.
The drill tool 3 is provided with teeth that cut
into the rock of the ground S by turning at high speed,
thereby grinding it into small pieces.
To prevent the borehole from collapsing, a casing
11 is laid. The casing 11 is made up of tubular
elements or pipes that retain the inside wall of the
borehole P. The casing elements line said wall and are
CA 02925247 2016-03-23
=
18
fastened by cementing. The casing elements descend
under their own weight and their diameters decrease
with increasing depth. A first casing pipe is laid as
soon as the drill tool 3 has drilled through the
surface sou, and it is cemented into the hole by
cernent. A base casing element is fastened ta the end
that is flush with the surface. Ail of the following
casing pipes are also cemented at their bases and their
upper ends are suspended from the base casing element.
After casing the first drilling phase, drilling
is continued with a tool 3 of diameter smaller than the
inside diameter of the casing string.
Mud is taken from a mud pit or mud tank 12,
pumped by a mud pump 13, and sent via a mud une or mud
hases 14 ta the mud injection head 8. The mud injection
head 8 injects mud into the drill string 4.
The mud lubricates and cleans the drill tool 3.
The mud pressure aise helps ta cut into the rock of the
ground S. It prevents the borehole P from collapsing by
filling the space between the drill string 4 and the
casing 11, and also makes it possible ta bring the
cuttings generated by the drill tool 3 back up. The mud
and the cuttings are brought back up the borehole P,
through vibrating screens that separate the mud from
the cuttings. The separated mud returns to the mud pit
12. The mud is generally made up of water and of clay,
and its composition varies as a function of the ground
through which the borehole is cut.
CA 02925247 2016-03-23
19
Figures 2 and 3 show the drilling draw-works 2 of
the drilling rig 1 in more detail. The drilling draw-
works 2 comprise a drum 21 on which the draw-works
cable C is wound. The drilling draw-works 2 further
comprises a brake 23 for preventing the cable C from
unwinding from the draw-works. It further comprises a
brake control 24 or "brake lever" 24, for controlling
loads or tools lowered into the borehole P. The brake
control 24 thus makes it possible to control the speed
and deceleration of the hoist hook 7, optionally to the
extent of stopping it from moving. The brake 23 is a
mechanical brake having brake bands 25a, 25b. This
brake 23 is made up of two metal bands (not shown)
equipped with internai linings 26a, 26b. Each band
wraps around a respective rim 27a, 27b constrained to
rotate with the drum 21. One end of each band is
stationary, while the other end is connected via a set
of cams and connection rods 28 to one end 29 of the
hinged lever 24 (the brake control 24), thereby making
it possible to gear down the force to be exerted on the
other end 30 of the brake control 24.
Figure 4 shows an embodiment of a device 40 of
the invention. The brake control or brake lever 24 is
shown as above.
The brake lever 24 has its first end 29 connected
mechanically to the brake bands 25a, 25b, which are
designed to act on the drum 2, and has its second end
provided with a first control handle 31 for
controlling the brake 23. The brake lever 24 is
CA 02925247 2016-03-23
implemented in the form of a hinged lever. The first
contrai handle 31 is used by an operator ta control
loads and tools lowered down the borehole P during
drilling.
5 The contrai
device 40 also includes actuation
means 32. The actuation means 32 are configured ta be
controlled and arranged ta act mechanically on the
brake lever 24. The actuation means are implemented in
the form of an electric actuator or "jack", or in the
10 form of a torque motor.
The contrai device 40 also includes a second
brake contrai handle 33 arranged ta servo-control the
actuation means 32. The actuation means 32 thus procure
automatic contrai of the brake contrai device 40 for
15 controlling the brake 23.
The actuation means 32 thus procure automatic
contrai of the brake lever 24. The second contrai
handle 33 is sensitive, i.e. it includes a sensitive
sensor 34.
20 Figure 4
also shows a metal chain 35 enabling
the operator ta leave the work station. When said metal
chain is disposed between the brake lever 24 and the
floor on which the draw-works 2 stands, the brake 23
prevents any unwinding of the cable C from the draw-
works 2. The mounting of the additional or second brake
contrai handle 33 does flot prevent the metal chain 35
. CA 02925247 2016-03-23
21
from being put in place to lock the brake 23
mechanically.
A major advantage of this device is that the
actuation means 32 are arranged so that, when the brake
lever 24 is in a given position, the braking force
applied by the actuation means 32 increases when the
force exerted by the tool 3 on the cable C wound on the
draw-works 2 increases.
With reference to Figure 5, other aspects of the
control device 40 are described below. Ail of the
elements shown in Figure 4 are also shown in Figure 5.
The second control handle 33 includes and
incorporates the extensometer sensor 34. This sensor is
arranged to generate a handle control signal Si
relating to the pressure exerted on the second handle
33 by an operator's hand.
The control device 40 includes electronic means
41. The electronic means 41 are implemented in the form
of a central processing unit. These electronic means 41
are configured to control the actuation means 32 on the
basis of:
¨ the control signal Si emitted by the second
brake control handle 33, and referred to as the "handle
signal"; and/or
¨ information on the weight conditions to which
the tool 3 is subjected and which are measured by
= CA 02925247 2016-03-23
22
signais S2 and/or S3 emitted by a hydraulic indicator
or gauge 36; and/or
¨ a differential mud pressure at the tool 3, as
measured by a signal S4; and/or
¨ a signal S5 indicating the maximum torque
withstood by the tool 3 in rotation; and/or
¨ the maximum speed of penetration of the tool 3
into the ground S, as measured by a signal S6 by means
of a digital sensor 42 mounted on the axle of the drum
of the draw-works 2.
The electronic control means 41 control the
actuation means 32 by using a control signal S7.
In accordance with the invention, the mechanical
action exerted by the brake control device is active.
The actuation means 32 are arranged to act
actively on the brake lever 24 so that the brake bands
25a, 25b fully or partially prevent and/or allow
rotation of the drum.
The actuation means 32 are arranged to act in
accordance with a command on the brake lever 24 so that
the brake bands 25a, 25b fully or partially prevent
and/or allow rotation of the drum.
The actuation means are arranged to act on the
brake control lever 24 symmetrically, i.e. they are
suitable for delivering an action in the braking
= CA 02925247 2016-03-23
23
direction for braking the drum 21 and a symmetrical
action in the releasing direction for releasing the
drum.
The second control handle 33 thus makes it
possible to measure the force of the hand of the
operator and its direction so as to servo-control the
movements and the thrust force of the actuation means
32 on the brake lever 24.
A major advantage of this device is that it can
be readily installed on ail manual drilling rigs
designed with draw-works having a brake associated with
a manual control lever, with a minimum of mechanical
mounting and assembly, and without affecting the
structural integrity of the initial component elements
of the draw-works.
The hydraulic indicator 36 is instrumented to
deliver two electrical signais S2 and S3 for indicating
respectively the weight suspended on the hoist hook 7
and the weight applied to the tool 3. In a variant of
this embodiment, the weight suspended on the hoist hook
7 and the weight applied to the tool 3 are known by
placing a pressure sensor on the hydraulic portion of
the indicator 36 and an extensometer on the cable known
as the "deadline" of the drilling draw-works 2.
The electronic central processing unit 41 thus
sends, reads, and processes the following signais by
performing the following operations:
= CA 02925247 2016-03-23
'
24
¨ sending a management signal S8 to a graphic
display 43;
¨ receiving a return signal from the graphic
display 43 for displaying a return signal S9;
¨ computing the instantaneous speed of
penetration of the tool 3 on the basis of the signal
S6;
¨ calculating the instantaneous weight on the
tool 3 via the signals S2 and S3;
¨ managing safety systems and values flot to be
exceeded for the various drilling parameters;
¨ computing and controlling the servo-control of
the actuation means 32 via the signal S7; and
¨ determining the angular position of the kelly
relative to the vertical.
The limits not to be exceeded are transmitted by
the return signal S9 and may include:
¨ the maximum speed of penetration of the tool 3
into the ground S; and/or
¨ the maximum torque withstood by the tool 3 in
rotation; and/or
¨ the maximum weight supported by the tool 3.
CA 02925247 2016-03-23
,
. .
The graphic display 43 makes it possible to view
in digital, bar chart, or galvanometer form, ail or
some of the various signais Si, S2, S3, S4, S5, S6, S7,
S8, S9 in real time.
5 Potentiometer settings Bi, B2, B3, B4 are
accessible on the bottom of the color display 43 for
the limits of certain parameters and auxiliary
controls. These potentiometer settings make it possible
to define the various limits flot to be exceeded. These
10 settings also make it possible to define the targets
for weights on the tool and/or the target for
differential mud pressure on the tool.
In automatic drilling, the central processing
unit 41 takes control of the actuation means 32 in
15 association with the second brake control handle 33.
Thus, the device 40 is designed to control
borehole drilling such a manner as to obtain:
¨ greater efficiency and less wear on the drill
tool 3;
20 ¨ greater quality for the walls of the borehole
so as to reduce the risk of jamming while the casing 11
is descending;
¨ monitoring of the maximum rotation torque and
of the speed of penetration so as to avoid drilling
25 incidents such as destruction of the drill tool.
= CA 02925247 2016-03-23
26
The electronic contrai means 41 are arranged ta
servo-control the actuation means 32 ta a setpoint
speed of movement of the end 30 of the brake lever 24.
Speed servo-control enables the operator ta feel
sensations close ta the ones the operator feels with
manual drilling. This applies in a braking mode for
braking the cable C, and in an unwinding mode for
unwinding said cable C. The braking mode is defined as
an operating mode of the device 40 of the invention, in
which operating mode the brake bands 25a, 25b act on
the drum 21 ta exert a braking force. In this mode, the
device 40 of the invention partially prevents rotation
of the drum 21. The braking force may be such that the
rotation of the drum 21 is stopped.
The device 40 further includes an emergency stop
device of the kill switch or panic button type having
the function of interrupting any servo-control of the
contrai lever 40, and of thereby enabling operation of
the contrai lever 40 ta go over ta purely manual
operation.
In a variant of this first servo-control variant,
the electronic contrai means 41 are arranged ta servo-
control the actuation means 32 ta a setpoint thrust
force in a braking mode.
In yet another variant of the servo-control, the
electronic contrai means 41 are arranged ta servo-
control the actuation means 32 ta a setpoint position
of the contrai lever 24.
CA 02925247 2016-03-23
27
The actuation means 32 are powered via an
uninterruptible power supply 44 including means for
detecting any interruption in the electrical power
supply. The electronic means 41 are configured to
control the actuation means 32 so as to actuate them in
the braking direction whenever power supply
interruption is detected by the power supply
interruption detection means. Naturally, the braking
direction is the direction in which the device 40 of
the invention partially prevents rotation of the drum
21.
In a second embodiment (not shown and described
only insofar as it differs from the first embodiment of
the control device 40) may alternatively or also
include a strain sensor for measuring strain on the
second control handle 33. This strain sensor may, for
example, be implemented by a strain gauge.
A method is also proposed for controlling a brake
control for controlling the brake 23 of a drum 21 of a
draw-works 2 equipping a drilling rig 1 operating a
drill tool 3 in a borehole P, which method implements a
brake control 40 as described above. The brake control
40 includes a brake lever 24 having a first end 29
connected mechanically to brake bands 25a, 25b designed
to act on the drum 21, and a second end 30 provided
with a first brake control handle 31.
The method comprises:
CA 02925247 2016-03-23
28
¨ applying a mechanical force on said brake
lever 24, the force applied being controlled to procure
servo-control of the position of the brake lever 24
and/or of a thrust force exerted on the brake lever 24;
¨ generating a control signal S7 for servo-
controlling the position and/or the thrust force, on
the basis of a second control handle 33 disposed
substantially at the second end 30 of the brake lever
24; and
¨ servo-controlling the brake lever 24 procured
by an actuator 32 controlled from an electronic control
unit 41 arranged to process the control signal Si
generated on the basis of the second control handle
and/or of the information relating to the operating
conditions of the draw-works 2;
¨ the information processed by the electronic
control unit 41 comprising information relating to the
weight applied to the drill tool 3 and/or to the
differential mud pressure at the drill tool 3 and/or to
the maximum torque in rotation withstood by the drill
tool 3 and/or to the maximum speed of penetration of
the tool into the ground.
Naturally, the invention is not limited to the
above-described examples and numerous changes can be
made to these examples without going beyond the ambit
of the invention.
, CA 02925247 2016-03-23
29
For example, in various variants that may
optionally be mutually combined:
1) some and/or ail of the information collected
by the central processing unit 41 may be transferred to
a control centre that is remote from the rig 1. The
signal relating to the information collected may, for
example, by transported via the Internet to an
expertise center via a cable or satellite link.
2) an added control signal for controlling the
actuation means 32 via the central processing unit 41
may corne from a control center remote from the rig 1.
The added signal may, for example, be transported via
the Internet.
3) the hand of an operator may advantageously be
replaced by any article arranged to exert a force
and/or a pressure on the second control handle 33. For
example, such an article may be an actuator on the
control handle and that is controlled remotely.
4) the signais S2 and S3 may advantageously be
used respectively to read the instantaneous weight on
the drill tool 3 and to read the parameter for the
desired weight on the drill tool, i.e. the target
weight on the drill tool that will have been set by the
operator via a knurled wheel included in the indicator
36. In which case, the operator sets the target weight
via the knurled wheel of the indicator 36 and flot via
CA 02925247 2016-03-23
the potentiometer settings. The same change may be made
to a device indicating the differential mud pressure.
