WO2002073004A1 - Systeme de telemetrie avec amcr synchrone utilisable dans un puits de forage - Google Patents

Systeme de telemetrie avec amcr synchrone utilisable dans un puits de forage Download PDF

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Publication number
WO2002073004A1
WO2002073004A1 PCT/US2001/007181 US0107181W WO02073004A1 WO 2002073004 A1 WO2002073004 A1 WO 2002073004A1 US 0107181 W US0107181 W US 0107181W WO 02073004 A1 WO02073004 A1 WO 02073004A1
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WO
WIPO (PCT)
Prior art keywords
outputs
encoded
sensor
data
data source
Prior art date
Application number
PCT/US2001/007181
Other languages
English (en)
Inventor
Wallace R. Gardner
Roger L. Schultz
Original Assignee
Halliburton Energy Services, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Halliburton Energy Services, Inc. filed Critical Halliburton Energy Services, Inc.
Priority to BRPI0116924A priority Critical patent/BRPI0116924B1/pt
Priority to GB0318327A priority patent/GB2392685B/en
Priority to PCT/US2001/007181 priority patent/WO2002073004A1/fr
Priority to US10/061,921 priority patent/US6819260B2/en
Publication of WO2002073004A1 publication Critical patent/WO2002073004A1/fr

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B47/00—Survey of boreholes or wells
    • E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
    • G01V1/22—Transmitting seismic signals to recording or processing apparatus
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
    • G01V1/40—Seismology; Seismic or acoustic prospecting or detecting specially adapted for well-logging

Definitions

  • the present invention relates generally to telemetry systems utilized in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides a synchronous CDMA telemetry system for use in a wellbore.
  • wireline logging telemetry systems are not designed to transmit data from widely distributed data sources. Instead, the data sources used with wireline logging tools are typically closely arranged in a well. Transmission of data from widely distributed data sources, on the other hand, can cause delays in relative transmission times between the respective data sources, thereby altering the relationships between the transmitted data.
  • the method includes the steps of installing multiple sensors in a wellbore, multiplying each data bit of each sensor's output by a digital code and simultaneously transmitting the encoded sensor outputs to a remote location via a transmission channel.
  • Each of the sensors is included in a sensor node and produces a respective digital output.
  • the sensors are geophones widely distributed in a wellbore, and the sensor nodes are all connected to a cable serving as the transmission channel.
  • the codes used to encode the sensor outputs are unique to each of the sensors and are orthogonal with respect to each other.
  • the codes are walesh codes. In this manner, the encoded outputs may be transmitted simultaneously on the same transmission channel without interference or cross-talk between the transmissions.
  • the encoded sensor outputs are modulated on a carrier frequency prior to being summed on the transmission channel.
  • the resulting signal is received at the remote location, it is demodulated.
  • the demodulated signal is then separately multiplied by each of the codes to produce respective decoded transmissions containing separate contributions to the signal.
  • These separate decoded transmissions are then integrated over the length of each data bit to produce an output from which the original data may be interpreted.
  • the transmissions from the various sensor nodes are synchronized.
  • a phase lock loop is used to phase lock the transmissions.
  • a sliding correlator is used to obtain synchronization by adjusting an offset timer of each sensor node.
  • An early-late correlator is used to maintain synchronization.
  • FIG. 1 is a schematic view of a method embodying principles of the present invention
  • FIG. 2 is a schematic view of data transmission in the method of FIG. 1;
  • FIG. 3 is a flow chart illustrating data transmission synchronization in the method of FIG. 1;
  • FIG. 4 is a schematic view of a data telemetry system used in the method of FIG. 1.
  • FIG. l Representatively illustrated in FIG. l is a method 10 which embodies principles of the present invention.
  • directional terms such as “above”, “below”, “upper”, “lower”, etc., are used only for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein maybe utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present invention.
  • the data source nodes include geophones 12.
  • the geophones 12 are biased outwardly from a tubing string 14 by bias members or springs 16.
  • the springs 16 bias the geophones 12 into contact with a wellbore 18, which may be cased as shown in FIG. 1, or which maybe uncased.
  • geophones 12 are illustrated in FIG. 1 as merely an example of the wide variety of data sources which ma be used in a method incorporating principles of the present invention. Other types of sensors and other types of data sources may be used in keeping with the principles of the invention.
  • FIG. 1 Only a small fraction of the total number of geophones 12 is depicted in FIG. 1. Preferred installations may include a hundred or more geophones 12 distributed along thousands of feet of the wellbore 18. However, it is to be clearly understood that any number of geophones 12 may be used in the method 10.
  • the geophones 12 communicate with a transceiver 20 located at the earth's surface or other remote location via a coaxial cable 22 extending into the well.
  • the cable 22 serves as a transmission channel for communication between the transceiver 20 and each of the geophones 16.
  • other types of transmission channels may be used in the method 10.
  • communication between the geophones 12 and the transceiver 20 may be via electromagnetic waves, acoustic pulses transmitted via fluid in the well, acoustic pulses transmitted via the tubing string 14, or any other type of transmission channel.
  • the method 10 includes provisions for synchronizing the transmissions from each of the nodes, so that data transmissions from all of the nodes are received at the transceiver 20 as if they simultaneously originated at a single location along the cable 22. Referring additionally now to FIG. 2, data transmission in the method 10 is schematically represented.
  • data sources 24, 26 are depicted in FIG. 2 for clarity of illustration and description, but it is to be clearly understood that any number of data sources maybe used.
  • the data sources 24, 26 are two of the geophones 12 shown in FIG. 1, but it is to be understood that any other type of data source may be used instead of, or in addition to, geophones.
  • Data output from the data sources 24, 26 is preferably in the form of a stream of digital bits, and so the output of an otherwise analog-type sensor would, for example, preferably be converted into digital form.
  • Each bit of data from data source 24 is multiplied by a unique code Ci by a multiplier 28 downhole, thereby encoding the data.
  • each bit of data from data source 26 is multiplied by another unique code C2 by a multiplier 30 downhole, thereby encoding that data.
  • the output of each additional data source would likewise be multiplied by another respective unique code.
  • the codes Ci, C2 are preferably of the type known to those skilled in the art as orthogonal codes, for purposes described more fully below.
  • orthogonal codes prevents interference and cross-talk between the transmissions.
  • the codes Ci, C2 are of the type known to those skilled in the art as walesh codes.
  • the data is modulated with a carrier frequency fc by respective modulators 32, 34. Note that the same carrier frequency fc is used in modulating the encoded output of each of the data sources 24, 26.
  • each of the data sources 24, 26 are then summed on a transmission channel 36.
  • This step is represented in FIG. 2 by a summing device 38, which may be a part of a transmitter of each data source node including, for example, a directional coupler.
  • each data source node may include a separate device for performing this function.
  • the transmission channel 36 is the cable 22.
  • any other type of transmission channel maybe used in place of the cable 22.
  • each of the above-described steps is performed downhole.
  • the data source 24, multiplier 28 and modulator 32 are part of one data source node 40
  • the data source 26, multiplier 30 and modulator 34 are part of another data source node 42, each of which is positioned downhole.
  • Each data source node 40, 42 may also include a summing device 38, as described above.
  • An alternative method of modulating and summing the encoded outputs of the data sources 24, 26 would be to first sum the encoded data and then modulate the summed and encoded data in a central downhole transmitter.
  • the transmission channel 36 extends from the data source nodes 40, 42 to a remote location.
  • the remote location is the transceiver 20 at the earth's surface.
  • any other remote location may be used, without departing from the principles of the present invention.
  • the encoded and modulated data is received at the remote location, where it is demodulated and decoded.
  • the carrier frequency fc is extracted from the signal using demodulators 44, 46. Note that, as depicted in FIG. 2, separate demodulators 44, 46 are utilized, but it will be readily appreciated that a single demodulator could alternatively be used.
  • the demodulated signal is then separately multiplied by each of the codes Ci, C2 using multipliers 48, 50, respectively. Due to the fact that the codes Ci, C2 are orthogonal to each other, this multiplying step decodes the signal, in that the output of multiplier 48 includes contributions to the signal from the data source 24 but no contributions to the signal from the data source 26, and the output of multiplier 50 includes contributions to the signal from the data source 26 but no contributions to the signal from the data source 24. Note that, with some types of orthogonal codes, the codes should be transposed prior to this multiplying step.
  • the method 10 permits the data outputs of the data sources 24, 26 to be simultaneously transmitted to a remote location via a single transmission channel 36 and using a single carrier frequency fc, and then to be separated from each other at the remote location, without interference and cross-talk between the signals.
  • demodulators 44, 46, the multipliers 48, 50 and integrators 52, 54 in the method 10 are preferably included in the transceiver 20 at the earth's surface as shown in FIG. 1. However, it is to be clearly understood that any or all of these elements may be otherwise positioned, without departing from the principles of the invention.
  • the method 10 includes provisions for synchronizing transmissions of the encoded data bits from the respective data nodes 40, 42.
  • synchronization of the transmissions from the data nodes 40, 42 in the method 10 is schematically represented.
  • the separate data transmissions are locked in phase by means of a phase lock loop 56 using techniques well known to those skilled in the art.
  • a sine wave or "tone" is broadcast continuously from the transceiver 20 to all of the downhole nodes 40, 42.
  • Clocks in each of the nodes 40, 42 are locked in phase with the tone.
  • the tone is broadcast via the transmission channel 36.
  • a sliding correlator 58 is then used to synchronize the timing of each node to a reference node by adjusting an offset timer in each node 24, 26.
  • Such sliding correlators are well known to those skilled in the art.
  • the reference node is chosen as the node farthest from the transceiver 20, but this is not necessary in keeping with the principles of the invention.
  • the synchronization is maintained by means of an early-late correlator 60 of the type well known to those skilled in the art.
  • the early-late correlator 60 maintains synchronization by subtracting an early correlation (for example, 1 bit early) from a late correlation to maintain synchronization.
  • step 62 representing a synchronization check
  • the sliding correlator 58 is used to again obtain synchronization. If the result of step 62 is "YES”, then the early-late correlator 60 continues to maintain the synchronization.
  • the transceiver 20 includes elements of the phase lock loop 56 (for example, conventional means for broadcasting the timing tone), the sliding correlator 58 and the early-late correlator 60.
  • the phase lock loop 56 for example, conventional means for broadcasting the timing tone
  • the sliding correlator 58 for example, conventional means for broadcasting the timing tone
  • the early-late correlator 60 for example, conventional means for broadcasting the timing tone
  • the 40, 42 include additional elements 64, 66 of the phase lock loop 56 and offset timers 68, 70.
  • the outputs of each of these are input to transmitters 72, 74, which then transmit the encoded data to the transceiver 20 via the cable 22.
  • the transmitter 72 may include the multiplier 28, modulator 32 and a summing device 38
  • the transmitter 74 may include the multiplier 30, modulator 34 and a summing device 38.
  • each of the above elements may be otherwise positioned, without departing from the principles of the invention.
  • the cable 22 is represented in FIG. 4 by three lines 76, 78, 80.
  • Line 76 represents the broadcast of the timing tone as part of the phase lock loop 56. As described above, the tone is broadcast to each of the nodes 40, 42.
  • the separate downhole elements 64, 66 of the phase lock loop 56 receive the tone and lock the clocks in the transmitters 72, 74 in phase.
  • Line 78 represents the transmission of the encoded, modulated and summed data from the nodes 40, 42 to the transceiver 20.
  • Line 80 represents transmissions from the transceiver 20 to the offset timers 68, 70 of the nodes 40, 42 as a result of the sliding correlation described above.
  • the offset timers 68, 70 delay transmissions from the transmitters 72, 74 as needed to obtain synchronization of the transmissions, as described above.
  • the phase lock loop tone represented by line 76 may be broadcast at one frequency
  • the transmissions from the nodes 40, 42 to the transceiver 20 may use another carrier frequency fc
  • the transmissions from the transceiver 20 to the offset timers 68, 70 of the nodes 40, 42 may use yet another frequency.
  • multiple frequency sub-bands are used for transmissions between downhole data source nodes 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108 and multiple transceivers 110, 112, 114 positioned at a remote location.
  • the data source nodes 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108 may be similar to the data source nodes 40, 42 described above, and the transceivers 110, 112, 114 may be similar to the transceiver 20 described above.
  • transceivers and data source nodes may be used in keeping with the principles of the invention.
  • the illustrated data source nodes 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108 are installed in a well, such as the geophones 12 shown in FIG. 1, and the transceivers 110, 112, 114 are located at the earth's surface, but other positionings of these elements may be used without departing from the principles of the invention.
  • the frequency sub-bands are obtained by dividing a total usable system bandwidth by a desired number of sub-bands. For example, if the total usable system bandwidth is 80 MHz and the desired number of sub-bands is four, then each sub-band will have a bandwidth of 20 MHz.
  • a separate sub-band is used for transmissions between respective sets of data source nodes and transceivers. For example, transmissions between the data source nodes 86, 88, 90, 92 and the transceiver 110 would use a first sub- band, transmissions between data source nodes 94, 96, 98, 100 and the transceiver 112 would use a second sub-band and transmissions between the data source nodes 102, 104, 106, 108 and the transceiver 114 would use a third sub- band. These transmissions are represented in FIG. 5 by separate lines 116, 118, 120, but it is to be understood that the transmissions are preferably via a single transmission channel, such as the cable 22 described above.
  • Transmissions from each set of data source nodes to its respective transceiver would be modulated on a carrier frequency within its respective sub-band.
  • the total usable system bandwidth is 80 MHz and the total number of data source nodes is 200, with a data transmission rate from each data source node of 150 kbps.
  • a desired number of sub-bands for this example ma be 20.
  • each sub- band has a bandwidth of 4 MHz (80 MHz / 20)
  • the number of data source nodes per sub-band is 10 (200 / 20)
  • the data rate per sub-band is 1.5 Mbps (150 kbps 10).
  • the total system data rate is, thus, 30 Mbps (1.5 Mbps X 20).

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Remote Sensing (AREA)
  • Mining & Mineral Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Geophysics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Fluid Mechanics (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Acoustics & Sound (AREA)
  • General Physics & Mathematics (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)

Abstract

L'invention concerne un système de télémétrie avec AMCR synchrone (10) destiné à être utilisé dans un puits de forage. Dans une forme de réalisation, chaque bit d'information des sorties numériques (24, 26) de multiples sources de données du puits de forage est multiplié par un code orthogonal (28, 30) unique à chaque source de données. Les sorties codées obtenues sont modulées sur une fréquence porteuse (32, 34) et additionnées (38) dans une voie de transmission (36). Le signal résultant est démodulé (44, 46) à un emplacement distant et multiplié séparément par chacun des codes (48, 50) afin de séparer les apports au signal provenant de chaque source de données. Les sorties individuelles démodulées et décodées sont ensuite intégrées (52, 54) sur toute la longueur de chaque bit d'information.
PCT/US2001/007181 2001-03-07 2001-03-07 Systeme de telemetrie avec amcr synchrone utilisable dans un puits de forage WO2002073004A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BRPI0116924A BRPI0116924B1 (pt) 2001-03-07 2001-03-07 método de comunicar dados em um furo de poço
GB0318327A GB2392685B (en) 2001-03-07 2001-03-07 Synchronous CDMA telemetry system for use in a wellbore
PCT/US2001/007181 WO2002073004A1 (fr) 2001-03-07 2001-03-07 Systeme de telemetrie avec amcr synchrone utilisable dans un puits de forage
US10/061,921 US6819260B2 (en) 2001-03-07 2002-02-01 Synchronous CDMA telemetry system for use in a wellbore

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2001/007181 WO2002073004A1 (fr) 2001-03-07 2001-03-07 Systeme de telemetrie avec amcr synchrone utilisable dans un puits de forage

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WO2002073004A1 true WO2002073004A1 (fr) 2002-09-19

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BR (1) BRPI0116924B1 (fr)
GB (1) GB2392685B (fr)
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0859472A1 (fr) * 1997-02-13 1998-08-19 Alcatel Emetteur à accès multiple par répartition de code
US5905721A (en) * 1996-09-26 1999-05-18 Cwill Telecommunications, Inc. Methods for channel estimation and signal detection of CDMA signals
US5933454A (en) * 1994-06-02 1999-08-03 Amati Communications Corporation Multi-carrier data transmissions system using an overhead bus for synchronizing multiple remote units
WO2000029717A2 (fr) * 1998-11-17 2000-05-25 Schlumberger Technology Corporation Systeme de communications comportant des canaux redondants
WO2001008326A1 (fr) * 1999-07-23 2001-02-01 Itt Manufacturing Enterprises, Inc. Multiplexeur et procede amrc a synchronisation d'elements pour obtenir des signaux a enveloppe constante

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6144859A (en) * 1993-08-27 2000-11-07 Aeris Communications, Inc. Wireless cellular communicator system and apparatus
US6046685A (en) * 1996-09-23 2000-04-04 Baker Hughes Incorporated Redundant downhole production well control system and method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5933454A (en) * 1994-06-02 1999-08-03 Amati Communications Corporation Multi-carrier data transmissions system using an overhead bus for synchronizing multiple remote units
US5905721A (en) * 1996-09-26 1999-05-18 Cwill Telecommunications, Inc. Methods for channel estimation and signal detection of CDMA signals
EP0859472A1 (fr) * 1997-02-13 1998-08-19 Alcatel Emetteur à accès multiple par répartition de code
WO2000029717A2 (fr) * 1998-11-17 2000-05-25 Schlumberger Technology Corporation Systeme de communications comportant des canaux redondants
WO2001008326A1 (fr) * 1999-07-23 2001-02-01 Itt Manufacturing Enterprises, Inc. Multiplexeur et procede amrc a synchronisation d'elements pour obtenir des signaux a enveloppe constante

Also Published As

Publication number Publication date
GB2392685A (en) 2004-03-10
BRPI0116924B1 (pt) 2015-10-13
BR0116924A (pt) 2004-10-13
GB0318327D0 (en) 2003-09-10
GB2392685B (en) 2005-01-19

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