U.S. patent application number 14/131449 was filed with the patent office on 2014-05-15 for telemetry system, a pipe and a method of transmitting information.
This patent application is currently assigned to Nederlandse Organisatie voor toegepast- natuurwetenschappelijk onderzoek TNO. The applicant listed for this patent is Gert Jan Heerens, Arno Willem Frederik Volker, Rik Vos. Invention is credited to Gert Jan Heerens, Arno Willem Frederik Volker, Rik Vos.
Application Number | 20140133276 14/131449 |
Document ID | / |
Family ID | 46582050 |
Filed Date | 2014-05-15 |
United States Patent
Application |
20140133276 |
Kind Code |
A1 |
Volker; Arno Willem Frederik ;
et al. |
May 15, 2014 |
Telemetry System, a Pipe and a Method of Transmitting
Information
Abstract
The invention relates to a telemetry system for use in a pipe
having a wall, comprising a transmitter adapted to generate at
least one acoustic wave in a frequency range of about 50-300 kHz
and to inject the acoustic wave in the wall of the pipe, wherein
the transmitter is further arranged to binary code information
conceived to be transmitted with the acoustic wave. The invention
further related to a pipe comprising the telemetry system and to a
method of transmitting information via a pipe.
Inventors: |
Volker; Arno Willem Frederik;
(Delft, NL) ; Vos; Rik; (Delft, NL) ;
Heerens; Gert Jan; (Delft, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Volker; Arno Willem Frederik
Vos; Rik
Heerens; Gert Jan |
Delft
Delft
Delft |
|
NL
NL
NL |
|
|
Assignee: |
Nederlandse Organisatie voor
toegepast- natuurwetenschappelijk onderzoek TNO
Delft
NL
|
Family ID: |
46582050 |
Appl. No.: |
14/131449 |
Filed: |
July 6, 2012 |
PCT Filed: |
July 6, 2012 |
PCT NO: |
PCT/NL2012/050486 |
371 Date: |
January 29, 2014 |
Current U.S.
Class: |
367/82 |
Current CPC
Class: |
E21B 17/006 20130101;
G01V 11/002 20130101; E21B 47/16 20130101; H04L 25/4906
20130101 |
Class at
Publication: |
367/82 |
International
Class: |
E21B 47/16 20060101
E21B047/16 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 8, 2011 |
EP |
11173208.7 |
Claims
1. A telemetry system for use in a pipe having a wall, comprising a
transmitter adapted to generate at least one acoustic wave in a
frequency range of about 50-300 kHz and to inject the acoustic wave
in the wall of the pipe, wherein the transmitter is further
arranged to binary code information conceived to be transmitted
with the acoustic wave.
2. The system according to claim 1, wherein the acoustic wave is a
L(0, 2) or T(0, 1) wave.
3. The system according to claim 1, wherein the transmitter
comprises an array of elements.
4. The system according to claim 3, wherein the transmitter is
ring-shaped.
5. The system according to claim 1, wherein the pipe comprises
consecutive segments, the transmitter being adapted to be
positioned between the consecutive segments.
6. The system according to claim 1, wherein the transmitter is
adapted to generate a binary code using pre-defined frequencies of
a plurality of the acoustic waves.
7. The system according to claim 1, wherein the system further
comprises an amplifier for amplifying a signal generated by the
transmitter, the amplifier being arranged to implement a
consistency check of a received binary code.
8. The system according to claim 7, wherein the amplifier is
further arranged to generate an amplified frequency shifted
signal.
9. A pipe comprising the telemetry system according to claim 1.
10. The pipe according to claim 9, forming part of a drill
arrangement.
11. A method of transmitting information through a pipe comprising
the steps of: injecting at least one acoustic wave in a frequency
range of about 50-300 kHz in a wall of the pipe; wherein
information conceived to be transmitted with the acoustic wave is
binary coded.
12. The method according to claim 11, wherein for the at least one
acoustic wave a L(0, 2) or a T(0, 1) is selected.
13. The method according to claim 11, further comprising the steps
of: amplifying a signal generated by the transmitter; implementing
a consistency check of a received binary code.
14. The method according to claim 13, further comprising the step
of frequency shifting an amplified signal.
15. The method according to claim 11, wherein for the pipe a drill
pipe is used.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a telemetry system for use in a
pipe having a wall.
[0002] The invention further relates to a pipe.
[0003] The invention still further relates to a method of
transmitting information through a pipe.
BACKGROUND OF THE INVENTION
[0004] An embodiment of a pipe as is set forth in the opening
paragraph is known from EP 2 157 279. the known pipe comprises a
transmitter for generating an acoustic signal with a frequency of a
few kHz at a first location near a distal portion of the pipe, a
receiver located at a further position in the pipe for receiving
the acoustic signal and for attempting to synchronize the receiver
at the transmitter frequency and depending on a success of the
synchronization step either to carry on data transmission or to
adjust the transmission frequency.
[0005] It is a disadvantage of the known pipe that due to
reflections in the joints of the segmented pipe only a limited
frequency bands around about 2-3 kHz can be used. This has a
further disadvantage that low frequencies limit data transmission
rates considerably, which is not desirable.
SUMMARY OF THE INVENTION
[0006] It is an object of the invention to provide an improved pipe
and a telemetry system for use with the pipe enabling data
transmission with increased transmission rates, wherein such
transmission is reliable and substantially error-free.
[0007] To this end the telemetry system for use in a pipe having a
wall comprises a transmitter adapted to generate at least one
acoustic wave in a frequency range of 50-300 kHz and to inject the
acoustic wave in the wall of the pipe, wherein the transmitter is
further arranged to binary code information conceived to be
transmitted with the acoustic wave. It will be appreciated that for
the pipe a drill pipe may be selected. It is found that the
frequency range of 50-300 kHz is particularly suitable to
accommodate a wall thickness range which may be used for industrial
pipes.
[0008] It is found that for a transmission using ultrasound waves
propagating in a wall of a pipe, a characteristic parameter (P) for
ultrasonic information transfer depends on a wave number multiplied
by wall thickness of a pipe. This variable (P) should be minimized
because for such variables having a high value the attenuation of
the signal in the material of the pipe increases accordingly:
P = 2 .pi. f C s D 2 , ##EQU00001##
[0009] wherein
[0010] f is the frequency of the acoustic wave propagating in a
wall of the pipe;
[0011] Cs is the shear velocity of the acoustic wave;
[0012] D is a thickness of the wall.
[0013] However, it is noted that the phase velocity of the acoustic
wave decreases with increasing the parameter (P). In addition, for
high values of the parameter (P) higher ultrasound frequencies may
be used which enable use of higher data transmission rates.
[0014] The invention has an advantage that no carrier wave is used.
The information conceived to be transmitted using the ultrasound
waves is binary coded using a pre-determined rule for the multiple
frequencies of the generated ultrasound waves. It is further found
that using the frequency range of 50-300 kHz high information rate
may be achieved, especially with respect to the carrier frequencies
below 40 Hz. In addition, it is found that there is a substantial
reduction of parasitic noise in the frequency range of 50-300 kHz.
Still further, it is found that a smaller design of the apparatus
is feasible when the transducer is tined to the higher frequencies,
i.e. the frequencies above 50 kHz.
[0015] For example, separate frequencies may be switched on/off for
data encoding according to the following exemplary rule: 50kHz=1;
51 kHz=0; 52 kHz=1, etc., that is even frequencies are assigned the
logic 1 and odd frequencies are assigned the logic 0.
[0016] Alternatively, it is also possible to assign frequency
groups, such as pairs, for coding. For example pairs (50, 51) kHz,
(52, 53) kHz, etc. may be used for binary coding information
conceived to be transmitted so that only one frequency from the
pair is transmitted. According to a rule, when 50 kHz is received,
the bit equals to 0, when 51 is received, the bit equals to 1, etc.
When none of the frequencies from the assigned pairs (or larger
groups) is received the threshold can be adapted to receive either
of the two. This method can be used for overcoming false 0 and to
increase confidence in data transfer at a cost of data rate.
[0017] In a particular embodiment of the telemetry system according
to the invention the acoustic wave is a L(0, 2) or T(0, 1)
wave.
[0018] In particular, it is found that the L(0, 2) wave is
particularly useful because the particle motion in this wave is
mainly longitudinal which causes a low liquid coupling (i.e. low
attenuation) and a good coupling between the successive segments of
the pipe.
[0019] In a further embodiment of the telemetry system according to
the invention the transmitter comprises an array of elements.
Piezoelectric elements or elements operating using other
technology, such as electromagnetic acoustic transducers may be
used. Preferably, the transmitter is ring-shaped.
[0020] It is found that an array-shaped or ring-shaped embodiment
of the transmitted is useful, as it may be easily integrated
between the segments of the pipe. Usually, the segments are about
10 meter long. A transmitter operated according to the invention is
capable of transmitting the acoustic waves carrying information
through several segments. Three to five segments may be transmitted
through without a need for amplification.
[0021] Because the pipes are much longer than 30 meters, it may be
necessary to built-in an amplifier on a path of the ultrasonic
waves emanated from the transmitter. For example, the amplifiers
may be provided every 3-5 segments.
[0022] In a further embodiment of the telemetry system according to
the invention, the amplifier is adapted to implement a consistency
check of a received binary code.
[0023] Those skilled in the art will readily appreciate which per
se known consistency check algorithms may be used for this purpose.
It will be further appreciated that such smart logic may form part
of the amplifier, or, alternatively, the signal received by the
amplifier may be processed by a dedicated smart logic unit and
returned to the amplifier for amplification. For the simplicity
reasons, the latter arrangement is referred to as an amplifier.
[0024] In a still further embodiment of the telemetry system
according to the invention the amplifier is further arranged to
generate an amplified frequency shifted signal.
[0025] It is found to be particularly useful to allow a frequency
shift of the amplified signal with respect to the signal feeding
the amplifier. For example, for a first amplifier, receiving the
in-frequencies of 50, 51, 52, 53, 54 . . . x, kHz, the amplified
signal may have the following frequencies: 50.1, 51.1, 52.1, 53.1,
54.1, . . . x' kHz. This feature is found to be advantageous as
interference between the amplified and the incoming signal is
substantially avoided.
[0026] The pipe according to the invention comprises the telemetry
system as is set forth with respect to the foregoing.
[0027] The method of transmitting information through a pipe,
according to the invention, comprises the steps of injecting at
least one acoustic wave in a frequency range of 50-300 kHz in a
wall of the pipe; wherein information conceived to be transmitted
with the acoustic wave is binary coded. The method is found to be
particularly suitable to transmit information from a drill location
through a drill pipe.
[0028] In the preferable embodiments of the method according to the
invention, for the at least one acoustic wave a L(0, 2) or a T(0,
1) is selected. The method may further comprise the steps of
amplifying a signal generated by the transmitter; implementing a
consistency check of a received binary code.
[0029] In a still further advantageous embodiment of the method
according to the invention it further comprises the step of
frequency shifting an amplified signal with respect to the incoming
signal.
[0030] These and other aspects of the invention will be discussed
with reference to drawings wherein like reference signs correspond
to like elements. It will be appreciated that the drawings are
presented for illustrative purposes only and may not be used for
limiting the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 presents in a schematic way an embodiment of an
overview of a drill set-up.
[0032] FIG. 2 presents in a schematic way an embodiment of a
telemetry system according to an aspect of the invention.
[0033] FIG. 3 presents in a schematic way an embodiment of a
ring-shaped transmitter provided in a joint of a pipe.
DETAILED DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 presents in a schematic way an embodiment of an
overview of a drill set-up. A drilling installation 10 may be
provided for implementing suitable underground exploration works.
For example, drilling for investigating oil bearing strata may be
envisaged.
[0035] A pipe D, notably a drill pipe, may be used for conducting
control signals Sin from the control unit to the drill bit 6 and
for conducting information at least about the drill environment
Sout from the drill bit 6 up to the control system 3. In according
to an embodiment of the telemetry system according to the invention
a pipe D may be provided comprising a suitable number of pipe
segments 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h interconnecting a control
system 2 located above the ground with a drill bit 6 located
distally. The pipe segments are interconnected by suitable joints
5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h. Preferably, the pipe is
manufactured from metal. However, other materials, such as metal
may be used.
[0036] In accordance with the invention a telemetry system 7 is
provided comprising a transmitter (not shown) adapted to generate
at least one acoustic wave in a wall of the pipe D, wherein the
frequency of the at least one acoustic wave is in the range of
50-300 kHz and wherein the transmitter is further arranged to
binary code information conceived to be transmitted using the said
at least one wave. It will be appreciated that it is found that a
single wave mode is sufficient for transmitting the information
using two or more frequencies.
[0037] For example, when a single frequency is used the amplitude
of the acoustic signal may be used for coding the information into
the binary code. For example, when the amplitude is set above a
pre-defined threshold the value of the byte is 1, otherwise it is
0. Alternatively, a number of frequencies may be used for binary
coding the information. As has been explained earlier, a rule can
be used for assigning a particular frequency or frequencies to the
value 1 and assigning other frequency or frequencies to the value
1.
[0038] In accordance with an aspect of the invention, the signal
generated by the transmitter may be amplified by an amplifier
provided in one or more joints of the pipe segments. For example,
an amplifier 8 may be installed in the joint 5f to receive the
acoustic signal propagating in the wall of the pipe D, to carry out
a consistency check and to generate an amplified signal, which is
preferably frequency shifted with respect to the incoming signal.
This measure is found to be particularly advantageous for
preventing undesirable signal interference post amplification.
[0039] It will be appreciated that information suitable for
transmitting from the drill bite towards the control system may be
collected by a suitable sensor or sensors arranged on or within the
drill bite. This method of data collecting regarding particular
characteristics of the drill environments is known per se and will
not be explained here in details. For example, known systems
arranged in the drill bite may comprise sensor or sensors adapted
to provide information about the drilling process and the direction
in which the drill bit is propagating. It will be further
appreciated that particularly for exploration of oil bearing layers
in strata drill strings may be quite long, up to several
kilometers, for example.
[0040] FIG. 2 presents in a schematic way an embodiment of a
telemetry system according to an aspect of the invention. As has
been explained earlier, the pipe 20 may comprise a plurality of
pipe segments 21a, 21b, . . . , 21n, 21n+1, joined together. In
accordance with the invention the drill bite 26 comprises a
transmit/receive unit 24 arranged to collect control data from the
control system for controlling or adjusting the drill bite and to
transmit information data collected by suitable sensor or sensors
provided on the drill bite 26 upstream towards the control system.
The control system is usually located above the ground. The
transmitter is adapted to generate at least one acoustic wave in a
frequency range of about 50-300 kHz and to inject the acoustic wave
in the wall of the pipe, wherein the transmitter is further
arranged to binary code information conceived to be transmitted
with the acoustic wave. The acoustic wave or waves will propagate
in the direction P upstream the pipe D towards the control system
(not shown). In accordance with a further aspect of the invention a
suitable plurality of amplifiers 22a, 22b, 22c is built-in the
joints connecting the segments of the pipe D for amplifying the
incoming signal. Preferably such amplifiers are arranged with a
distance between them of about 3-5 meters and are further adapted
to carry out a consistency check of the incoming binary word. In
addition, for improving the signal transmission quality, the
amplifiers 22a, 22b, 22c may be adapted to frequency shift the
output amplified signal with respect to the input signal.
[0041] FIG. 3 presents in a schematic way an embodiment of a
ring-shaped transmitter provided in a joint of a pipe 30. The
ring-shaped transmitter 32 is preferably built-in the pipe segment
33 and is coaxially arranged with it. The collar 31 which may be
used for affixing the adjacent segments to each other may be used
for firmly holding the transmitter 32. The collar may be provided
with a suitable plurality of affixing elements 31a. The ring-shaped
transmitter 32 is preferably manufactured from a piezoelectric
material and may be implemented either as a continuous material, or
as a suitable array of individual piezoelectric elements. The
latter embodiment is advantageous in case the transmitter 32 is
operable for generating a plurality of acoustic waves in the wall
of the pipe 33.
[0042] While specific embodiments have been described above, it
will be appreciated that the invention may be practiced otherwise
than as described. Moreover, specific items discussed with
reference to any of the isolated drawings may freely be
inter-changed supplementing each outer in any particular way. The
descriptions above are intended to be illustrative, not limiting.
Thus, it will be apparent to one skilled in the art that
modifications may be made to the invention as described in the
foregoing without departing from the scope of the claims set out
below.
* * * * *