U.S. patent application number 13/159820 was filed with the patent office on 2011-12-22 for pipeline instrumentation and control system.
Invention is credited to Brendan Peter Hyland, Andrew Jaffrey, Mark Rhodes, Mark Volanthen.
Application Number | 20110308796 13/159820 |
Document ID | / |
Family ID | 42471749 |
Filed Date | 2011-12-22 |
United States Patent
Application |
20110308796 |
Kind Code |
A1 |
Hyland; Brendan Peter ; et
al. |
December 22, 2011 |
Pipeline instrumentation and control system
Abstract
A pipeline instrumentation and control system comprising a first
electrically insulated radiating cable for controlled radiation and
reception of electromagnetic signaling carried to a second
electrically insulated radiating cable wherein first and second
electrically insulated radiating cables are axially disposed along
a production well pipe and wherein first axially radiating cable
comprises a section configured to substantially overlap second
radiating cable section and further wherein electrical signals
present in first radiating cable section is configured to induce a
corresponding signal in said second radiating cable section to
facilitate the transfer of electromagnetic radiation therebetween.
The present invention provides reliable data communication from any
location within the production system and improves reservoir
management, well planning and resource exploitation.
Inventors: |
Hyland; Brendan Peter;
(Edinburgh, GB) ; Volanthen; Mark; (Hampshire,
GB) ; Jaffrey; Andrew; (Inverurie, GB) ;
Rhodes; Mark; (West Lothian, GB) |
Family ID: |
42471749 |
Appl. No.: |
13/159820 |
Filed: |
June 14, 2011 |
Current U.S.
Class: |
166/255.1 ;
166/66 |
Current CPC
Class: |
E21B 17/028 20130101;
E21B 47/13 20200501; H04B 5/0031 20130101; H04B 5/0093 20130101;
H04B 5/0037 20130101 |
Class at
Publication: |
166/255.1 ;
166/66 |
International
Class: |
E21B 47/09 20060101
E21B047/09; E21B 47/00 20060101 E21B047/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 16, 2010 |
GB |
1010095.6 |
Claims
1. A pipeline instrumentation and control system for the transfer
of data in tubing, comprising; first and second radiating cables
being electrically insulated radiating cables for controlled
radiation and reception of electromagnetic signals; said radiating
cables being disposed in said tubing and arranged parallel to a
longitudinal axis of said tubing; a first end section of said first
radiating cable being arranged in parallel to a second end section
of said second radiating cable so that said first and second end
sections overlap along said longitudinal axis of said tubing to
facilitate the transfer of electromagnetic radiation
therebetween.
2. A pipeline instrumentation and control system according to claim
1 wherein said first and second end sections are aligned in close
proximity.
3. A pipeline instrumentation and control system according to claim
1 wherein said first radiating cable is connected to a first
transceiver and said second radiating cable is connected to a
second transceiver to facilitate bi-directional signaling between
said first and second end sections.
4. A pipeline instrumentation and control system according to claim
1 wherein said first and second end sections overlap over a length
of approximately 5 m.
5. A pipeline instrumentation and control system according to claim
1 wherein said first and second ends are separated by a distance in
the range 1 to 30 mm.
6. A pipeline instrumentation and control system according to claim
1, wherein said first radiating cable is connected to a command
control center and said second radiating cable is connected to one
of group of devices comprising: a sensor, gauge, data logger,
electrical device and electro-mechanical device.
7. A pipeline instrumentation and control system according to claim
6 wherein said device is located in a wellbore.
8. A pipeline instrumentation and control system according to claim
1 wherein said tubing is production tubing located in a
wellbore.
9. A method of data transfer in a wellbore, comprising the steps
of: (a) locating a device in said wellbore; (b) providing a
pipeline instrumentation and control system in tubing of said
wellbore, comprising first and second radiating cables being
electrically insulated radiating cables for controlled radiation
and reception of electromagnetic signals; (c) connecting said
second radiating cable to said device; (d) running said first
radiating cable into the wellbore; (e) overlapping first and second
end sections of said first and second cables, respectively, in the
wellbore and thereby providing electromagnetic coupling; (f)
transmitting data from the sensor between said radiating cables and
up said first radiating cable to a control command centre.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of GB 1010095.6 filed
Jun. 16, 2010, which application is fully incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a radiating cable for the
transfer of data signals in a confined space. More particularly,
the present invention relates to a leaky radiating cable for the
transfer of signals within a pipe structure. Further, the invention
relates to a method for providing signal coupling between a first
transmission line and a second transmission line e.g. for a
hydrocarbon extraction facility.
BACKGROUND OF THE INVENTION
[0003] In some industrial applications communications may be
required between two pieces of equipment deployed inside a pipe
structure. One example of such an application is found in the oil
and gas industry. The extraction of hydrocarbons from a well system
is a very challenging task with such systems typically comprising a
complex network of metallic pipes through which oil or gas is
supplied from an underground reservoir to a production platform. In
the most complex installations the reservoir may be located within
the ground beneath the sea where a production pipe system is
utilized to carry extracted hydrocarbon from the seabed through a
riser to a production platform located at the surface of the
sea.
[0004] Typically, production operations require a great quantity of
command and control information relating to parameters and
conditions `downhole`. Such information typically includes
characteristics of pressure, temperature, flow rate, flow
composition, flow direction and so on, along with data relating to
the size and configuration of the borehole itself. The requirement
to provide such information is extremely challenging due to the
very constrained nature of the pipe structure. The pipe structure
is the most accessible route for any data signaling mechanism.
Generally, such command and control of production activities are
performed from a surface based control station on the surface
production platform. In general, valves and drilling mechanisms are
remotely controlled from the surface based control stations which
rely on analysis of sensor data often from critical locations
within the borehole pipe structure. Remote data gathering sensors
and control devices also require electrical power and this must
also be supplied from the surface based control stations.
[0005] Methods for remote signaling from downhole locations in a
well production system are well known in the art. For example `mud
pulsing` is a widely used telemetry system generating
characteristic data whilst drilling, and this is commonly referred
to as `measurement whilst drilling`. In general, the mud pulse
system uses variations in pressure in the mud fluid used in
production to transfer data to a control station. Pressure
variations are used to represent modulated data. However, these
systems suffer from interference from the acoustic noise generated
by drilling operations. Acoustic signaling within the pipe walls
and through the fluid carried by production pipes suffers from
similar limitations. Alternative techniques have been proposed such
as hard wired conductive cable systems which provide data and power
to remote locations within the pipe structure. This technique has
also been found to be unreliable in an extreme environment such as
in a well system. Furthermore, the production tubing and casing are
assembled in sections and this complicates deployment of a wired
system which has to be threaded through the centre of the pipe as
each section is deployed. The fluids which flow in the production
tubing and casing contain abrasive materials, are often chemically
reactive, and at high temperature and pressure. In this environment
electrically conductive cables and electrically conductive
connectors provide very low reliability. Moreover, hard wired
cables are permanently interfaced to control devices and sensors
and should one part of the system fail then this often results in
failure of the whole command and control network. Such single point
failure is highly undesirable in a well based production
facility.
[0006] In summary, the communication systems described above are
disadvantageous in that they are complicated in use, unreliable due
to the harsh environment in which they are exposed, and expensive
to install.
[0007] There is a need for a flexible system for reliably providing
data communications to remote equipment within a pipe structure,
for example within the casing of a sub-surface hydrocarbon
production system.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a
radiating cable system for the transfer of signals, for example
data signals, in a hostile environment such as a well system in
which signals are transferred in a simple manner.
[0009] In this description the term "radiating cable" is used to
describe a cable arrangement which electromagnetically couples part
of the electrical signal it carries into the surrounding media.
This coupling will, in practice, be bi-directional and a cable that
couples its signal with the surrounding media not only radiates
signals into the surrounding media but also couples external
electromagnetic signals that are present in the surrounding media
to generate a signal carried by the radiating cable. In this
description the term radiating cable is used as a concise
description of a general elongate insulated electrical conductor
system which provides radiation of electromagnetic signals into its
surrounding media and also generates an internal electrical signal
in response to external electromagnetic signals that are present in
the surrounding media.
[0010] It is another object of the present invention to provide a
radiating cable system for a hydrocarbon extraction well that
recognizes the constraints of production tubing arrangement and
provides an efficient communication link.
[0011] It is another object of the present invention to provide a
radiating cable system for the transfer of signals in which such
signals are transferred in a well system in a reliable manner.
[0012] It is a further object of the present invention to provide a
radiating cable system in which fluids and solids within pipes of a
well system do not adversely affect the system of the present
invention, thus providing the possibility of a continuous
communication link between data gathering sensors of a production
well pipe and a control station.
[0013] According to a first aspect of the present invention there
is provided a
[0014] pipeline instrumentation and control system for the transfer
of data in tubing, comprising;
[0015] first and second radiating cables being electrically
insulated radiating cables for controlled radiation and reception
of electromagnetic signals;
[0016] said radiating cables being disposed in said tubing and
arranged parallel to a longitudinal axis of said tubing;
[0017] a first end section of said first radiating cable being
arranged in parallel to a second end section of said second
radiating cable so that said first and second end sections overlap
along said longitudinal axis of said tubing to facilitate the
transfer of electromagnetic radiation therebetween.
[0018] In this way, by overlapping two cables the transfer of
signals, for example data signals, in a hostile environment such as
a well system is achieved in a simple and reliable manner. Further
as the cables do not require a physical connection, the system is
suitable for a hydrocarbon extraction well that recognizes the
constraints of production tubing arrangements and provides an
efficient communication link. As the cables are radiating cables,
fluids and solids within pipes of a well system do not adversely
affect the system, thus providing the possibility of a continuous
communication link between data gathering sensors of a production
well pipe and a control station.
[0019] Preferably, said first and second end sections are aligned
in close proximity. In this way, the cables require only to be near
each other to transfer the data.
[0020] Preferably, said first radiating cable is connected to a
first transceiver and said second radiating cable is connected to a
second transceiver to facilitate bi-directional signaling between
said first and second end sections. In this way, a bi-directional
communication link is provided.
[0021] Preferably, said first and second end sections overlap over
a length of approximately 5 m. In this way, a relatively short
overlapping distance is all that is required to provide reliable
data transfer.
[0022] Preferably, said first and second ends are separated by a
distance in the range 1 to 30 mm. In this way, data is reliably
transferred inside tubing as the ends are confined within the
tubing.
[0023] Preferably, said first radiating cable is connected to a
command control center and said second radiating cable is connected
to one of group of devices comprising: a sensor, gauge, data
logger, electrical device and electro-mechanical device. In this
way, a downhole data communication system is provided to transfer
data to devices located in the pipeline.
[0024] Preferably, said device is located in a wellbore. More
preferably, said tubing is production tubing located in a wellbore.
In this way, downhole gauges in a producing well can be operated
with the system of the present invention.
[0025] According to a second aspect of the present invention there
is provided a method of data transfer in a wellbore, comprising the
steps of:
[0026] (a) locating a device in said wellbore;
[0027] (b) providing a pipeline instrumentation and control system
according to the first aspect in tubing of said wellbore;
[0028] (c) connecting said second radiating cable to said
device;
[0029] (d) running said first radiating cable into the
wellbore;
[0030] (e) overlapping said first and second end sections in the
wellbore and thereby providing electromagnetic coupling;
[0031] (f) transmitting data from the sensor between said radiating
cables and up said first radiating cable to a control command
centre.
[0032] In this way, downhole permanent devices can be accessed by
intervention of a single cable into the production tubing. A
downhole connection is not required and the overlap will be known
to have been achieved by the reception of transferred data at a
surface of the tubing.
BRIEF DESCRIPTION OF DRAWINGS
[0033] A better understanding of the features and advantages of the
present invention will be obtained by reference to the following
detailed description that sets forth illustrative embodiments by
way of example only, in which the principles of the invention are
utilized, and the accompanying drawings of which:
[0034] FIG. 1 shows a simplified view of a radiating cable system
of present invention arranged within a production tubing of a
hydrocarbon extraction well according to an embodiment of the
present invention;
[0035] FIG. 2 shows a simplified view of a conventional co-axial
cable having a continuous outer shield to minimize transmission
line loss.
[0036] FIG. 3 shows a simplified view of a radiating co-axial cable
showing a shield formed by winding a conductive tape in a helical
arrangement with slots between turns to allow controlled leakage of
a signal (not shown) as it propagates along the cable according to
an embodiment of the present invention;
[0037] FIG. 4a shows a simplified view of a hydrocarbon production
pipe comprising first and second transceivers for communicating
with command center according to an embodiment of the present
invention;
[0038] FIG. 4b shows a simplified block diagram of the transceivers
and associated circuitry in block diagram for communicating between
command center and sensor and/or data logger and/or electrical
device and/or electro-mechanical device arranged within production
well tubing according to an embodiment of the present
invention;
[0039] FIG. 5 shows a simplified view of the radiating cable system
of the present invention comprising a first radiating cable
arranged in close proximity to a second radiating cable for
facilitating the transfer of signals between according to an
embodiment of the present invention;
[0040] FIG. 6 shows a simplified production tube within a casing of
a well production system;
[0041] FIG. 7 shows a simplified view of the radiating cable system
of the present invention comprising a first radiating cable
arranged in close proximity to a second radiating cable for
facilitating the transfer of signals between and arranged in a
production tube within a casing of a well production system
according to an embodiment of the present invention;
[0042] FIG. 8 shows a simplified overview of an example hydrocarbon
well production system incorporating the radiating cable system of
the present invention and depicting the advantages of the
cylindrical shape of the first radiating cable and second radiating
cable complementing the general design of production tubing or
annular space of a production tubing of a hydrocarbon extraction
well.
DETAILED DESCRIPTION OF THE INVENTION
[0043] FIG. 1 shows a simplified view of a radiating cable system
of the present invention arranged within a production tubing of a
hydrocarbon extraction facility. The radiating cable system 2
comprises a first radiating cable 4 and a second radiating cable 6
made generally of a first and second elongated radiating co-axial
axially extending cable. First and second radiating cables 4, 6 are
generally flexible in nature and as will described later for
allowing general manipulation during insertion and removal into and
out of hydrocarbon production tubing. In the current application, a
radiating cable is defined as controlled radiation of a signal
passed along the length of a cable. In one example embodiment a
first elongated radiating cable for coupling signals to a second
radiating cable has its shield formed by winding a conductive tape
in a helical arrangement with slots between turns to allow
controlled leakage of signals as it propagates along the cable.
[0044] Similarly, second radiating cable for the coupling signals
to first radiating cable has its shield formed by winding a
conductive tape in a helical arrangement. Slots between turns are
formed to allow controlled leakage of signals as they propagate
along the cable. Typically, coupling signals between first and
second co-axial cable is for the bi-directional signaling to/from
at least one sensor (e.g. for sensing characteristics pressure,
temperature, flow rate, flow composition, flow direction and so on)
to first or second transceiver. First and second radiating cable
have a continuous electrically protective shielding such as a
resilient material best suited to protect the cables from the
deleterious effects of production well environment. As will be
described later in detail, first and second radiating cables are
aligned in closed proximity to create a radiating cable system and
substantially aligned (as will be described later) with the axis of
the production tubing.
[0045] FIG. 2 shows a simplified view of a conventional co-axial
cable 10 having a continuous outer shield 12 which is provided to
minimize transmission line loss. Conventional co-axial cable is
generally shown having an electrical cable with an inner conductor
14 surrounded by a flexible, tubular insulating layer 16,
surrounded by a tubular conducting shield 12. Co-axial cables
provide protection of the transmission signal from external
electromagnetic interference. Co-axial cables are widely known in
the art and a full description is not disclosed herein.
[0046] Twisted pair transmission lines are often used to reduce
radiation and pick-up of transmitted data compared to single
unbalanced wire line. The twisted wires are held in close contact
and a balanced signal is carried by the wires. The magnetic field
generated by the outgoing current is almost exactly cancelled by
the field generated by the return current flowing in the opposite
direction. However, if a twisted pair of wires is terminated in a
reactive circuit it may be designed to be imbalanced. In this mode
the outgoing current is designed to be out of phase with the return
current in the twisted pair to a controlled degree so that the
magnetic fields generated by the currents flowing in opposite
directions do not completely cancel and a field is generated in the
surrounding media which can be used to stimulate an electric
current in a similar near-by radiating cable.
[0047] FIG. 3 shows a simplified view of a first radiating co-axial
cable which is adapted for the transmission of signals such as data
signals to a second transceiver (not shown) according to an
embodiment of the present invention. First radiating cable or is
constructed by means of a central conductor 24 separated from a
conducting shield 28 by an insulating dielectric 26. A shield 30 is
formed by winding a conductive tape in a helical arrangement. Slots
32 which are provided between turns allow controlled leakage of a
signal (not shown) as it propagates along the cable according to an
embodiment of the present invention. Partly removed for the purpose
of clarity is the electrically insulating protective shielding 30
which protects inner cable from the deleterious effects of the
production well environment.
[0048] The dielectric permittivity and diameter of an insulating
dielectric are designed to form a controlled impedance waveguide
between the conductor and shield. Shielding is covered by a
protective electrically insulating sleeve. Further, shield 30 is
formed by winding a conductive tape in a helical arrangement with
slots 32 between turns to allow controlled leakage of a signal as
it propagates along the cable. In one embodiment of the present
invention, slots 32 are formed along the entire length of first and
second radiating cable. In an alternative embodiment, slots are
formed at predetermined distances along first and second radiating
cable to aid in control of leakage of signal at predetermined
distance from surface based control station. As will be described
later, the radiating cable is terminated in its characteristic
impedance to prevent signal reflections. In an alternative
embodiment, the far end of the radiating cable could be connected
to a second impedance matched receive terminal. Preferably, the
radiating cable is driven by an amplifier matched to its
characteristic impedance. Although not depicted in the current
figure, radiating cables 4, 6 are connected to a transceiver that
is operable to transmit and receive electromagnetic signal to and
from a surface based control station 34.
[0049] In an example embodiment and as shown in FIG. 4a a
hydrocarbon production pipe is 1000 m long. A temperature sensing
instrument 67 is provided 950 m from the top side of the pipe.
Communications interface 60 is provided in a top side control
centre to provide an interface with pipe command and control system
68. Transmission line 61 is used to carry a data signal that
requests a measurement from temperature sensor 67. Transmission
line 61 is around 930 m long. This signal travels to transceiver 62
which generates a signal in radiating cable 63.
[0050] Radiating cable 63 is 20 m long and is positioned within the
pipe so that it overlaps radiating cable 64 over a 5 m section.
Transceiver 65 receives the coupled signal and generates a signal
on transmission line 66 suitable for interfacing with sensor 67. In
response sensor 67 generates a modulated signal in transmission
line 66 that represents the measured temperature. This modulated
signal is received by transceiver 65 which generates a conditioned
signal in radiating cable 64. Radiating cable 63 receives the
signal generated in radiating cable 64 and this signal is received
by transceiver 62. Transceiver 62 receives the coupled signal and
generates a signal on transmission line 66 suitable for
transmission over 930 m transmission line 61 back to communications
interface 60.
[0051] In another example embodiment of the present invention, the
pipeline instrumentation and control system of the present
invention may be used to control a valve inside the hydrocarbon
production pipe. Such a valve may be utilized to release pressure
within the drilled bore hole or may be used to seal a flow channel.
In any case, such a valve would rely on data communications for
operation. In such an example embodiment the valve is positioned a
great distance from a communications interface 60 such that the
control signal needs to be repeated prior to arriving at a top side
control centre 68. Transmission line 61 carries a data signal
containing a command signal for opening and/or closing a valve that
travels to transceiver 62. Transceiver 62 generates a corresponding
signal in radiating cable 63. As can be seen in the current figure,
first radiating cable is positioned within hydrocarbon production
pipe such that it overlaps second radiating cable over a
predetermined length. Due to the general conditions within such a
pipe, the length may be in the order of 5 m thus ensuring even
during fluid flow within the pipe that communication signal between
first and second radiating cable occurs. Transceiver 65 receives
the coupled signal and generates a control signal on transmission
line 66 suitable for interfacing to valve interface 67. Valve
interface may be one part of a general valve module that may
contain for example a processor, transceiver, data logger and
optionally a power supply. Consequently, valve is operationally
manipulated by received control signal. Such operational
manipulation may be one of opening and/or closing of said valve
with such manipulation being dependent on the requirements of the
command centre. Optionally and preferably, transmitter part of
transceiver forming part of general valve module sends a periodical
acknowledgment signal to the command centre such that command
centre personnel are aware of the current operational status of the
valve. In such a scenario, the transmitter part of the transceiver
generates a modulated signal being representative of the
acknowledgement signal. As previously discussed, the valve module
generates a modulated signal in transmission line 66 that
represents the acknowledged signal. This modulated signal is
received by transceiver 65 which generates a conditioned signal in
radiating cable 64. Radiating cable 63 receives the signal
generated in radiating cable 64 and this signal is received by
transceiver 62. Transceiver 62 receives the coupled signal and
generates a signal on transmission line 66 suitable for
transmission to communications interface 60.
[0052] Equally, the configuration of the pipeline instrumentation
and control system of the present invention may be used for
transmission of captured data from for example a data logger such
that the control system allows captured data in bore well within a
production pipe to be transmitted to a control centre. In such a
scenario, data from a valve unit, a drilling unit, a senor unit
e.g. for monitoring stability of pipe, and/or other device
generating data required by a command centre may be stored on a
data logger and transmitted periodically or constantly to the
command center.
[0053] As shown in FIG. 4b, container within a single housing are
first and second transceivers 62, 65. In practice, containment of
first and second transceivers held within a single housing affords
several advantages not least power supply considerations. Clearly,
and as depicted in the current figure, both transmitter and
receiver circuitry are powered from a single source 142 thus
ensuring easier power budget considerations. Circuitry 143 ensures
that power supply output is regulated prior to powering subsequent
circuitry.
[0054] As further shown in the current figure is a processor module
132 which runs specialized software under the command of control
center 68. Further, processor module is connected to timing circuit
141 such to provide a timing clock cycle and further interacted to
data interface 131.
[0055] Modulator 133 is connected to line interface 147 and
controlled by processor module 132. Modulator modulates incoming
signal from line interface 133 with its digital output converted to
an output signal by means of converter 134. To correct for signal
amplitude variations, analogue signal is amplifies by means of
amplifier 135 and then sent to radiating cable 146 as an outgoing
signal to sensor and/or data logger and/or electrical device and/or
electro-mechanical device within production well tubing by means of
transceiver switch 51.
[0056] Similarly, incoming signal (that is, incoming towards
control center 68) from sensor and/or data logger and/or electrical
device and/or electro-mechanical device arranged within production
well tubing is routed via switch S1 to receive amplifier. Output of
receive amplifier is connected to analogue to digital converter 139
such that digital signal is demodulated at demodulator 140 and
processed at module 132.
[0057] As can be seen in the current figure, modulator 133, digital
to analogue converter 134, amplifier 135, receive amplifier 138,
analogue to digital converter 139, demodulator 140 are all
connected to module 132 for signal processing.
[0058] FIG. 5 shows a simplified view of the radiating cable system
of the present invention comprising a first radiating cable 4
arranged in close proximity to a second radiating cable 6 for
facilitating the transfer of signals between according to an
embodiment of the present invention. Generally, length of radiating
cable system 2 of the present invention extends from surface based
control station 34 containing a transceiver 36 to sensors and
transceiver located deep within production tubing (not shown).
Transceivers are operable to transmit and receive electromagnetic
signals travelling along length of radiating cable. In the current
figure, first radiating cable is aligned in close proximity to
second transmission thus facilitating the bi-directional coupling
of electromagnetic signals leaking from slots 32 formed between
turns of shield. As will be described later, first and second
radiating cables forming radiating cable system 2 of the present
invention, are arranged within the dimensionally limited production
tubing, thus allowing close coupling between for the transfer of
electromagnetic signals.
[0059] In some embodiments radiating cable can be used to carry the
signal from the control center to the cable coupling region. In
other applications, for example where the range is greater or the
data rate is higher, a conventional transmission line may be used
to carry the signals from the control center some way down the pipe
to a local transceiver which interfaces with a radiating cable
section.
[0060] FIG. 6 shows a simplified view of a production tube 40
within a casing 42 and shown in cross section. As illustrated,
production tubing is positioned generally concentric to casing 42.
An annular space 44 is defined outside production tubing 40 and
inside casing 42. As will be shown later, the radiating cable
system of the present invention may be deployed within production
tubing or within annular space.
[0061] FIG. 7 shows a simplified view of the radiating cable system
2 of the present invention comprising a first radiating cable 4 in
close proximity to a second radiating cable 6 for facilitating the
transfer of signals therebetween and arranged in a production tube
40 within a casing 42 of a well production system according to an
embodiment of the present invention. Generally, first radiating
cable 4 is aligned in an overlapping and close proximity formation
to a second radiating cable 6 for facilitating the transfer of
signals therebetween. Preferably, gap between first and second
radiating cables in the area of transfer of electromagnetic
transmission area is between 1 to 30 mm. However, if the flow of
extracted material disturbs such distance then transfer of
electromagnetic transmission will continue albeit degraded. In any
case, distance between first and second radiating cables 4, 6 are
limited by the inner diameter of the production tubing. Preferably,
first and second radiating cables 4, 6 are aligned axially within
production tubing 40 thus minimizing the necessary length of
radiating cable required to facilitate electromagnetic
coupling.
[0062] FIG. 8 shows a simplified overview of an example hydrocarbon
well production system incorporating the radiating cable system 2
of the present invention and depicting the advantages of the
cylindrical shape of the first radiating cable and second radiating
cable 4, 6 complementing the general design of production tubing or
annular space 44 of the production tubing 40 of a hydrocarbon
extraction well.
[0063] As is depicted in the current figure, riser 50 links lower
stack at the seabed with topside rig 48. Control station 34 for the
hydrocarbon production system is typically located within topside
rig or platform and wellhead penetrates into seabed. Downhole
sensors and downhole tools are located within the production string
remotely from the control station 34. First and second generally
flexible transmission line are distributed throughout the
production piping and provide the transfer of signals (e.g. data
signals) between sensors deployed within the production tubing 40
and control station 34. The cylindrical shape of the first
radiating cable and second radiating cables 4, 6 are generally
arranged along the axial axis within the production tubing 40 (or
annular space) and complement the cylindrical design of production
tubing of a hydrocarbon extraction well. Furthermore, first
radiating cable 4 of the radiating cable system is generally
aligned to second radiating cable 6 and which is adapted to locally
radiate a portion of the signal carried by the first transmission
line 4. Second radiating cable aligned with first radiating cable
and further generally aligned with axis of production tubing 40
receives radiated signal from first radiating cable for
facilitating the data communication therebetween. Typically, for an
effective communication link, gap between first and second
transmission lines is in the order of between 1 to 30 mm. In any
case, distance between first and second transmission line is
limited by the dimensions such as the inner diameter of the
production tubing. First radiating cable 4 is connected to a first
transceiver that is operable to transmit and receive
electromagnetic signals and electromagnetically coupled to a second
insulated radiating cable that is connected to a second transceiver
that is operable to transmit and/or receive electromagnetic
signals. When the first radiating 4 moves into close proximity to
any part of radiating cable 6, short range electromagnetic coupling
is provided. That is to say, the connection for transmission
between first and second radiating cable 4, 6 is entirely based on
electromagnetic coupling. The radiating cable system supports
bi-directional data communications between surface based control
station 34 and an array of sensors deployed in the production well
facility. Since first and second radiating cables 4, 6 complement
the general shape of production tubing, the flow of extracted
hydrocarbon material from the well is therefore not impeded during
extraction thus allowing control signals from a control station 34
to sensors arranged within the production tubing to continue
without interruption. Furthermore solid material flowing within the
production tubing does not impact the radiating cable system since
any material will flow upwards towards the topside rig by-passing
the aligned radiating cable system.
[0064] Operational Deployment Method
[0065] In an example embodiment, the deployment of the pipeline
instrumentation and control system maybe be deployed within a
production well tubing according to the following example
method:
[0066] In a first step, a second radiating cable having a proximal
end and a distal end is located. Next, a sensor and/or data logger
and/or electrical device and/or electro-mechanical device is
connected to a distal end of second radiating cable. Next, a sensor
and/or data logger and/or electrical device and/or
electro-mechanical device connected to distal end of second
radiating cable is inserted into production well tubing at a distal
end of production well tubing. Next, sensor and/or data logger
and/or electrical device and/or electro-mechanical device connected
to distal end of second radiating cable is positioned at a distal
end of production well tubing. Next, first radiating cable
comprising a proximal end and a distal end and being of length Y
which is greater than length of said second radiating cable is
inserted into production well tubing. Next, distal end of first
radiating cable is manipulated within production cable well tubing
over proximal end of second radiating cable such that section of
first radiating cable overlaps section of second radiating cable.
Finally, proximal end of first radiating cable is connected to
command control center.
[0067] The radiating cable system described in this application
could alternatively be applied to a Floating Production, Storage,
and Offloading (FPSO) based system or a land based subsurface
production system.
[0068] Whilst the present invention may have particular
applicability to hydrocarbon extraction wells, it is should be
noted that the present invention is also applicable to other types
of industries, for example where the transfer of signals between a
control station and sensors and/or mechanical actuators inside
piping is required.
[0069] Various embodiments of the invention have been described
above. The descriptions are intended to be illustrative, not
limitative. Thus, it will be apparent to one skilled in the art
that certain modifications may be made to the invention as
described without departing from the scope of the claims set out
below.
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