NO20005441L - System and method for seismic exploration in a borehole using a group of fiber-optic sensors - Google Patents
System and method for seismic exploration in a borehole using a group of fiber-optic sensorsInfo
- Publication number
- NO20005441L NO20005441L NO20005441A NO20005441A NO20005441L NO 20005441 L NO20005441 L NO 20005441L NO 20005441 A NO20005441 A NO 20005441A NO 20005441 A NO20005441 A NO 20005441A NO 20005441 L NO20005441 L NO 20005441L
- Authority
- NO
- Norway
- Prior art keywords
- frequencies
- modulation frequencies
- hydrophone
- electronics
- light
- Prior art date
Links
- 230000003287 optical effect Effects 0.000 abstract 5
- 230000002452 interceptive effect Effects 0.000 abstract 2
- 239000002775 capsule Substances 0.000 abstract 1
- 239000000543 intermediate Substances 0.000 abstract 1
- 239000013307 optical fiber Substances 0.000 abstract 1
- 230000000737 periodic effect Effects 0.000 abstract 1
Landscapes
- Geophysics And Detection Of Objects (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
Et system for måling av akustiske bølger i undergrunnen som er sendt ut fra en akustisk kilde omfatter et antall laserkilder, et antall optiske sensorer i undergrunnen, minst en optisk detektor og elektronikk. Hver av laserkildene sender ut lys med sin egen frekvens. De optiske sensorer i undergrunnen mottar lyset og endrer lyset som reaksjon på de akustiske bølger. Den optiske detektoren mottar det endrede lys og gir som utgang et elektrisk signal. Elektronikken mottar det elektriske signal og omformer dette til seismisk dataformat. Det lys som sendes ut fra de optiske kilder er fortrinnsvis modulert med et antall forskjellige modulasjonsfrekvenser. Elektronikken kan benyttes til å demodulere signalet. Elektronikken kan demodulere det elektriske signal å blande det med periodiske bølgeformer som har frekvenser svarende til modulasjonsfrekvensene og det dobbelte av modulasjonsfrekvensene. Modulasjonsfrekvensene er valgt slik at minst en av de andre harmoniske frekvensene som er knyttet til modulasjonsfrekvensene er innfelt på en ikke-interfererende måte med det tilsvarende sett av første harmoniske frekvenser. Fortrinnsvis er modulasjons-frekvensene valgt slik at minst en av de første harmoniske frekvenser blir innfelt på en ikke-interfererende måte med det korresponderende sett av modulasjonsfrekvenser. Hydrofonen for måling av de akustiske signaler er i stand til å arbeide under trykk på minst 350 kg/cmog temperaturer på minst 130'C. Hydrofonen kan være anbrakt i en kabel med en diameter på mindre enn 38 mm. Hydrofonens'sensor omfatter fortrinnsvis en referansepinol, to målepinoler og en telemetriboks som alle er rettet inn på en koaksial ende-mot-ende-måte for å redusere profilet på hydrofonen. Fleksible mellomledd med spor for opptakelse av optiske fibre forbinder pinolene med hverandre. Referansepinolen og måledørene kan med fordel ha halvkule-formede endekapsler slik at de blir i stand til å arbeide under høyt trykk.A system for measuring acoustic waves in the subsoil emitted from an acoustic source comprises a number of laser sources, a number of optical sensors in the subsoil, at least one optical detector and electronics. Each of the laser sources emits light at its own frequency. The optical sensors in the subsurface receive the light and change the light in response to the acoustic waves. The optical detector receives the changed light and outputs an electrical signal. The electronics receive the electrical signal and convert it to seismic data format. The light emitted from the optical sources is preferably modulated with a number of different modulation frequencies. The electronics can be used to demodulate the signal. The electronics can demodulate the electrical signal mixing it with periodic waveforms having frequencies corresponding to the modulation frequencies and twice the modulation frequencies. The modulation frequencies are selected so that at least one of the other harmonic frequencies associated with the modulation frequencies is in a non-interfering manner with the corresponding set of first harmonic frequencies. Preferably, the modulation frequencies are selected so that at least one of the first harmonic frequencies is tuned in a non-interfering manner with the corresponding set of modulation frequencies. The hydrophone for measuring the acoustic signals is capable of operating under pressures of at least 350 kg / cm and temperatures of at least 130 ° C. The hydrophone can be placed in a cable with a diameter of less than 38 mm. The hydrophone's sensor preferably comprises a reference pin, two measuring pins and a telemetry box, all of which are aligned in a coaxial end-to-end manner to reduce the profile of the hydrophone. Flexible intermediates with tracks for receiving optical fibers connect the pinols to each other. The reference pin and the measuring doors can advantageously have hemispherical end capsules so that they are able to work under high pressure.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US09/429,048 US6728165B1 (en) | 1999-10-29 | 1999-10-29 | Acoustic sensing system for downhole seismic applications utilizing an array of fiber optic sensors |
| US09/430,058 US6269198B1 (en) | 1999-10-29 | 1999-10-29 | Acoustic sensing system for downhole seismic applications utilizing an array of fiber optic sensors |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| NO20005441D0 NO20005441D0 (en) | 2000-10-27 |
| NO20005441L true NO20005441L (en) | 2001-04-30 |
| NO333489B1 NO333489B1 (en) | 2013-06-24 |
Family
ID=27028013
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NO20005441A NO333489B1 (en) | 1999-10-29 | 2000-10-27 | System and method for seismic exploration in a borehole using a group of fiber-optic sensors |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2315438C (en) |
| NO (1) | NO333489B1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114324345B (en) * | 2021-11-01 | 2024-01-12 | 清华大学深圳国际研究生院 | Material imaging method and device, terminal equipment and storage medium |
| CN116691784B (en) * | 2023-06-06 | 2025-01-28 | 武汉理工大学 | A train real-time continuous positioning system and method |
| WO2025191512A1 (en) * | 2024-03-14 | 2025-09-18 | MAX-PLANCK-Gesellschaft zur Förderung der Wissenschaften e.V. | Optically controlled phase shifter and phased array for ultrasound applications |
-
2000
- 2000-07-27 CA CA 2315438 patent/CA2315438C/en not_active Expired - Lifetime
- 2000-10-27 NO NO20005441A patent/NO333489B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| NO333489B1 (en) | 2013-06-24 |
| CA2315438A1 (en) | 2001-04-29 |
| NO20005441D0 (en) | 2000-10-27 |
| CA2315438C (en) | 2009-11-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| CHAD | Change of the owner's name or address (par. 44 patent law, par. patentforskriften) |
Owner name: NORTHROP GRUMMAN GUIDANCE AND ELECTRONICS CO, US |
|
| MM1K | Lapsed by not paying the annual fees |