CA2455186A1 - Filters for canceling multiple noise sources in borehole electromagnetic telemetry system - Google Patents
Filters for canceling multiple noise sources in borehole electromagnetic telemetry system Download PDFInfo
- Publication number
- CA2455186A1 CA2455186A1 CA002455186A CA2455186A CA2455186A1 CA 2455186 A1 CA2455186 A1 CA 2455186A1 CA 002455186 A CA002455186 A CA 002455186A CA 2455186 A CA2455186 A CA 2455186A CA 2455186 A1 CA2455186 A1 CA 2455186A1
- Authority
- CA
- Canada
- Prior art keywords
- noise
- channel
- signal
- coupled
- adaptive filter
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
- E21B47/13—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 by electromagnetic energy, e.g. radio frequency
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V11/00—Prospecting or detecting by methods combining techniques covered by two or more of main groups G01V1/00 - G01V9/00
- G01V11/002—Details, e.g. power supply systems for logging instruments, transmitting or recording data, specially adapted for well logging, also if the prospecting method is irrelevant
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/04—Adaptation for subterranean or subaqueous use
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
- H01Q3/2605—Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
- H01Q3/2611—Means for null steering; Adaptive interference nulling
Abstract
An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters (74) use noise channels (68) as references to remove noise from the signal channel (66). Multiple noise channels are coupled to series connected adaptive filters (74) for removing each noise source from the signal channel. The order of noise removal is selected to remove the most significant first.
Claims (17)
1. Apparatus for removing noise generated by multiple sources from a received signal in a borehole electromagnetic telemetry system comprising;
first and second noise sensors detecting first and second noise sources and providing first and second noise channels representative of said noise sources, and first and second adaptive filters, having reference inputs coupled to said first and second noise channels respectively, said first adaptive filter having a primary input coupled to said received signal, and an output coupled to the primary input of said second adaptive filter.
first and second noise sensors detecting first and second noise sources and providing first and second noise channels representative of said noise sources, and first and second adaptive filters, having reference inputs coupled to said first and second noise channels respectively, said first adaptive filter having a primary input coupled to said received signal, and an output coupled to the primary input of said second adaptive filter.
2. Apparatus according to Claim 1 further comprising:
a first time delay unit coupling said second noise channel to said second adaptive filter reference input.
a first time delay unit coupling said second noise channel to said second adaptive filter reference input.
3. Apparatus according to Claim 2 wherein:
said first time delay unit delays said second noise channel by about the time required for the received signal to propagate through said first adaptive filter.
said first time delay unit delays said second noise channel by about the time required for the received signal to propagate through said first adaptive filter.
4. Apparatus according to Claim 3 further comprising:
a third noise sensor detecting a third noise source and providing a third noise channel representative of said third noise source, a third adaptive filter, having a reference input coupled to said third noise channel, said third adaptive filter having a primary input coupled to the output of said second adaptive filter.
a third noise sensor detecting a third noise source and providing a third noise channel representative of said third noise source, a third adaptive filter, having a reference input coupled to said third noise channel, said third adaptive filter having a primary input coupled to the output of said second adaptive filter.
5. Apparatus according to Claim 4 further comprising:
a second time delay unit coupling said third noise channel to said third adaptive filter reference input.
a second time delay unit coupling said third noise channel to said third adaptive filter reference input.
6. Apparatus according to Claim 5 wherein:
said second time delay unit delays said third noise channel by about the time required for the received signal to propagate through said first and second adaptive filters.
said second time delay unit delays said third noise channel by about the time required for the received signal to propagate through said first and second adaptive filters.
7. Apparatus for removing noise generated by a plurality of noise sources from a received signal in a borehole electromagnetic telemetry system comprising;
a plurality of noise sensors detecting a plurality of noise sources, a plurality of adaptive filters, each having a reference input coupled to one of said noise sensors, said adaptive filters coupled in series, with the first filter having a primary input coupled to said received signal and the last filter providing an improved signal from which noise from said noise sources has been substantially cancelled.
a plurality of noise sensors detecting a plurality of noise sources, a plurality of adaptive filters, each having a reference input coupled to one of said noise sensors, said adaptive filters coupled in series, with the first filter having a primary input coupled to said received signal and the last filter providing an improved signal from which noise from said noise sources has been substantially cancelled.
8. Apparatus according to Claim 7, further comprising:
time delay units coupled to the reference inputs of the second and subsequent adaptive filters delaying said signals from the noise sources to maintain synchronization between said noise sources and said received signal.
time delay units coupled to the reference inputs of the second and subsequent adaptive filters delaying said signals from the noise sources to maintain synchronization between said noise sources and said received signal.
9. The apparatus of Claim 7 wherein:
said noise sources are ranked in order of significance, with the most significant coupled to the first adaptive filter and the least significant coupled to the last adaptive filter.
said noise sources are ranked in order of significance, with the most significant coupled to the first adaptive filter and the least significant coupled to the last adaptive filter.
10. The apparatus of Claim 9 wherein the order of significance is based on the amplitude of noise channels produced by said noise sensors.
11. The apparatus of Claim 10 wherein the noise channel having the greatest amplitude is considered the most significant.
12. The apparatus of Claim 9 wherein the order of significance is based on the magnitude of each noise source which is contained in the received signal.
13. The apparatus of Claim 12 wherein the noise channel generating the greatest noise amplitude in the signal is considered the most significant.
14. The apparatus of Claim 9 wherein the order of significance is based on the magnitude of signal which is contained in each noise channel.
15. The apparatus of Claim 14 wherein:
the noise channel containing the least signal is considered the most significant.
the noise channel containing the least signal is considered the most significant.
16. Apparatus for improving the signal to noise ratio of a signal channel in a borehole electromagnetic telemetry system operating in the presence of a plurality of noise sources comprising:
a plurality of noise sensors, each providing a noise channel; and a plurality of noise cancellers, each having a noise channel input receiving one of said noise channels, a signal channel input, and an output providing a signal with improved signal to noise ratio;
a first of said cancellers having its signal channel input coupled to a telemetry system signal channel and the remaining cancellers each having its signal channel input coupled to the output of another canceller to provide a series connection of noise cancellers.
a plurality of noise sensors, each providing a noise channel; and a plurality of noise cancellers, each having a noise channel input receiving one of said noise channels, a signal channel input, and an output providing a signal with improved signal to noise ratio;
a first of said cancellers having its signal channel input coupled to a telemetry system signal channel and the remaining cancellers each having its signal channel input coupled to the output of another canceller to provide a series connection of noise cancellers.
17. The apparatus of Claim 16 wherein:
each noise canceller comprises an adaptive filter.
each noise canceller comprises an adaptive filter.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US09/923,205 | 2001-08-06 | ||
| US09/923,205 US6657597B2 (en) | 2001-08-06 | 2001-08-06 | Directional signal and noise sensors for borehole electromagnetic telemetry system |
| PCT/US2002/025074 WO2003013215A2 (en) | 2001-08-06 | 2002-08-06 | Filters for canceling multiple noise sources in borehole electromagnetic telemetry system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2455186A1 true CA2455186A1 (en) | 2003-02-20 |
| CA2455186C CA2455186C (en) | 2010-02-16 |
Family
ID=25448305
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002456637A Expired - Lifetime CA2456637C (en) | 2001-08-06 | 2002-07-03 | Directional signal and noise sensors for borehole electromagnetic telemetry system |
| CA2455186A Expired - Lifetime CA2455186C (en) | 2001-08-06 | 2002-08-06 | Filters for canceling multiple noise sources in borehole electromagnetic telemetry system |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002456637A Expired - Lifetime CA2456637C (en) | 2001-08-06 | 2002-07-03 | Directional signal and noise sensors for borehole electromagnetic telemetry system |
Country Status (7)
| Country | Link |
|---|---|
| US (2) | US6657597B2 (en) |
| AU (2) | AU2002355522B2 (en) |
| BR (2) | BRPI0211731B1 (en) |
| CA (2) | CA2456637C (en) |
| GB (1) | GB2398315B (en) |
| NO (2) | NO20040518L (en) |
| WO (2) | WO2003014769A1 (en) |
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-
2001
- 2001-08-06 US US09/923,205 patent/US6657597B2/en not_active Expired - Lifetime
-
2002
- 2002-07-03 BR BRPI0211731-2A patent/BRPI0211731B1/en unknown
- 2002-07-03 AU AU2002355522A patent/AU2002355522B2/en not_active Expired
- 2002-07-03 CA CA002456637A patent/CA2456637C/en not_active Expired - Lifetime
- 2002-07-03 GB GB0403157A patent/GB2398315B/en not_active Expired - Lifetime
- 2002-07-03 BR BR0211731-2A patent/BR0211731A/en active IP Right Grant
- 2002-07-03 WO PCT/US2002/021891 patent/WO2003014769A1/en not_active Application Discontinuation
- 2002-08-06 AU AU2002331010A patent/AU2002331010B2/en not_active Expired
- 2002-08-06 CA CA2455186A patent/CA2455186C/en not_active Expired - Lifetime
- 2002-08-06 WO PCT/US2002/025074 patent/WO2003013215A2/en not_active Application Discontinuation
-
2003
- 2003-09-29 US US10/673,971 patent/US7268696B2/en not_active Expired - Lifetime
-
2004
- 2004-02-04 NO NO20040518A patent/NO20040518L/en not_active Application Discontinuation
- 2004-02-04 NO NO20040494A patent/NO338862B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| GB2398315B (en) | 2005-06-29 |
| NO338862B1 (en) | 2016-10-24 |
| GB0403157D0 (en) | 2004-03-17 |
| WO2003014769A1 (en) | 2003-02-20 |
| NO20040518L (en) | 2004-04-01 |
| CA2456637A1 (en) | 2003-02-20 |
| NO20040494L (en) | 2004-04-01 |
| AU2002331010B2 (en) | 2006-04-13 |
| AU2002355522B2 (en) | 2008-02-07 |
| WO2003013215A2 (en) | 2003-02-20 |
| BR0211731A (en) | 2004-09-21 |
| US6657597B2 (en) | 2003-12-02 |
| GB2398315A (en) | 2004-08-18 |
| US20030025639A1 (en) | 2003-02-06 |
| BRPI0211731B1 (en) | 2020-11-10 |
| CA2455186C (en) | 2010-02-16 |
| US20040069514A1 (en) | 2004-04-15 |
| CA2456637C (en) | 2009-04-14 |
| US7268696B2 (en) | 2007-09-11 |
| WO2003013215A3 (en) | 2003-07-24 |
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Effective date: 20220808 |