1887
Volume 67 Number 6
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Marine seismic vibrators are generally considered to be less intrusive than airguns from an environmental perspective. This is because they emit their energy spread out in time, rather than in a single, high‐intensity pulse. There are also significant geophysical benefits associated with marine vibrators, and they stem from the ability to specify in detail the output acoustic waveform. The phase can be specified independently at each frequency. Such detailed control cannot be achieved with conventional airgun sources, where the phase can only be modified using simple overall time delays. The vibrator phase can be employed in several different ways: it can be applied to the overall source phase in a sequence so that it varies from one source point to the next; it can be applied to the individual vibrators within the source array so the source directivity is changed; it can be applied to the overall source phase of each source in a simultaneous source acquisition. Carefully designed phase sequences can attenuate the residual source noise, and this in turn allows extra source points to be interleaved between the conventional ones. For these extra source points, the relative phase of the vibrators within the array can be chosen to create a transverse gradient source, which illuminates the earth predominantly in directions out of the plane of the sail line without left/right ambiguity. If seismic vibrator data are acquired using interleaved conventional and transverse gradient sweeps, more information is collected per kilometre of vessel travel than is the case in conventional acquisition. This richer data acquisition leads to the possibility of acquiring all the necessary seismic data in a shorter time. Three‐dimensional reconstruction techniques are used to recover the same image quality that would have been obtained using the conventional, more time‐consuming acquisition. For a marine vibrator to be suitable for these techniques it must, in general terms, have ‘high fidelity’. The precise device specifications are defined through realistic end‐to‐end simulations of the physical systems and the processing. The specifications are somewhat more onerous than for a conventional vibrator, but they are achievable. A prototype vibrator that satisfies these requirements has been built. In a simulated case study of a three‐dimensional deep‐water ocean bottom node survey, the seismic data could have been acquired using marine vibrators in one third of the time that it would have taken using airguns.

Loading

Article metrics loading...

/content/journals/10.1111/1365-2478.12708
2018-11-14
2020-05-26
Loading full text...

Full text loading...

References

  1. BagainiC.2008. Low‐frequency vibroseis data with maximum displacement sweeps. The Leading Edge27, 582–591.
    [Google Scholar]
  2. BeckA. and TeboulleM.2009. A fast iterative shrinkage‐thresholding algorithm for linear inverse problems. SIAM Journal on Imaging Sciences2, 183–202.
    [Google Scholar]
  3. BirdJ.M., PeacockJ.H. and WalkerL.J.1984. Development of a hydraulic transducer for marine seismic. 54th SEG annual international meeting, Atlanta, Expanded Abstracts, 825–826.
  4. ChouT.G., HicksD., SydoraL., IyiolaS., NworahN. and ArowoloI.2010. OBN (ocean bottom nodes) acquisition for reservoir management and surveillance at Agbami Field, Nigeria. 80th SEG annual international meeting, Houston, TX, Expanded Abstracts, 3756–3758.
  5. FelthamA., GirardM., JenkersonM., NechayukV., GriswoldS., HendersonN.et al. 2017. The Marine Vibrator Joint Industry Project: four years on. Exploration Geophysics49, 675–687.
    [Google Scholar]
  6. HaldorsenJ., DeslerJ.F. and ChuD.1985. Use of vibrators in a marine seismic source. 55th SEG annual international meeting, Expanded Abstracts, 509–511.
  7. HallidayD.F., LawsR.M. and GardenM.2015a. Signal and noise in a shallow‐water ocean‐bottom cable survey. 85th SEG annual international meeting, New Orleans, Expanded Abstracts, 120–124.
  8. HallidayD.F., LawsR.M., HopperstadJ.‐F., MuyzertE. and CosteE.2015b. Frequency‐sparse seismic data acquisition and processing. US patent US20140278116A1.
  9. HallidayD.F., LawsR.M., ÖzbekA. and HopperstadJ.‐F.2017. Separating simultaneous sources using phase‐sequencing and reconstruction in marine seismic vibrators. 79th EAGE meeting, Paris, Expanded Abstracts, We‐P3‐15.
  10. HallidayD.F. and MooreI.2018. A comparison of random and periodic marine simultaneous‐source encoding. The Leading Edge37, 471a1–471a11.
    [Google Scholar]
  11. HampsonG. and JakubowiczH.1995. The effect of source and receiver motion on seismic data. Geophysical Prospecting43, 221–244.
    [Google Scholar]
  12. HerrmannF.J., WangD., HennenfentG. and MoghaddamP.P.2008. Curvelet‐based seismic data processing: a multiscale and nonlinear approach. Geophysics73, A1–A5.
    [Google Scholar]
  13. HopperstadJ.‐F., LawsR. and KraghE.2008. Where is the center of a multi‐depth marine source array? 78th SEG annual international meeting, Las Vegas, Expanded Abstracts, 40–44.
  14. JohnsonG.R., ThompsonI. and WalkerL.J.1988. The GECO marine vibrator system. 58th SEG annual international meeting, Las Vegas, Expanded Abstracts, 71–74.
  15. KraghE., LawsR.M., HopperstadJ.‐F., MorganG. and KireevA.2012. Reducing the size of the seismic source with a 4C towed marine streamer. 74th EAGE meeting, Copenhagen, Expanded Abstracts, Z014.
  16. KristiansenP., OgunsakinA., EsotuM., ZdravevaO., HootmanB. and QuadtE.2014. Deepwater OBN – exploiting data‐processing possibilities. 76th SEG annual international meeting, Denver, Expanded Abstracts, 4258–4262.
  17. LandrøM.2008. The effect of noise generated by previous shots on seismic reflection data. Geophysics73, Q9–Q17.
    [Google Scholar]
  18. LawsR.M.2012a. Simultaneous marine vibrators. United States Patent Application, Publication No. US 2014/0334257 A1.
  19. LawsR.M.2012b. Marine vibrator sweeps with reduced smearing and/or increased distortion tolerance, Publication No. US2013/0343153A1.
  20. LawsR.M.2013. Determining a seismic vibrator signature. United States Patent Application, Publication No. US20140283615A1.
  21. LawsR.M. and HallidayD.F.2013. Seismic data apparition from phase shifted sources. United States Patent Application, Publication No. US 2017/0269241 A1.
  22. LawsR.M., HallidayD.F., ÖzbekA. and HopperstadJ.‐F.2016. Exploiting the control of phase in marine vibrators. First Break34, 65–74.
    [Google Scholar]
  23. LawsR. and KraghE.2002. Rough seas and time‐lapse seismic. Geophysical Prospecting50, 195–208.
    [Google Scholar]
  24. LawsR.M., KraghE. and MorganG.2008. Are seismic sources too loud? 70th EAGE meeting, Rome, Expanded Abstracts, B026.
  25. LawsR.M. and MoriceS.P.1999. A method of seismic surveying, a marine vibrator arrangement, and a method of calculating the depths of seismic sources. European Patent Office EP1214610B8.
  26. LawsR.M., ParkesG.E. and HattonL.1988. Energy interaction: the long‐range interaction of seismic sources. Geophysical Prospecting36, 333–348.
    [Google Scholar]
  27. MoerigR., BarrF.R. and NylandL.2002. Simultaneous shooting using cascaded sweeps. 72nd SEG annual international meeting, Salt Lake City, Expanded Abstracts, 2002‐0074.
  28. MooreI., DragosetB., OmmundsenT., WilsonD., WardC. and EkeD.2008. Simultaneous source separation using dithered sources. 78th SEG annual international meeting, Las Vegas, Expanded Abstracts, 2806–2810.
  29. MosherC., LiC., MorleyL., JiY., JaniszewskiF., OlsonR.et al. 2014. Increasing the efficiency of seismic data acquisition via compressive sensing. The Leading Edge33, 386–391.
    [Google Scholar]
  30. NOAA
    NOAA2016. Technical guidance for assessing the effects of anthropogenic sound on marine mammal hearing, Underwater Acoustic Thresholds for Onset of Permanent and Temporary Threshold Shifts, NOAA Technical memorandum NMFS‐OPR‐55.
  31. ÖzbekA., VassalloM., ÖzdemirK., van ManenD.‐J. and EggenbergerK.2010. Crossline wavefield reconstruction from multicomponent streamer data: part 2 – joint interpolation and 3D up/down separation by generalized matching pursuit. Geophysics75, WB69–WB85.
    [Google Scholar]
  32. PopperA.N., HawkinsA.D., FayR.R., MannD.A., BartolS., CarlsonT.J.et al. 2014. Sound exposure guidelines for fishes and sea turtles. Technical report for ANSI‐ S3/SC1, ASA S3/SC1.4 TR‐2014, ASA Press.
  33. PotterG., MannA., JenkersonM. and RodriguezJ.M.1997. Comparison of marine vibrator, dynamite, and airgun sources in the transition zone. 59th EAGE meeting, Geneva, Expanded Abstracts, B018.
  34. RobertssonJ.O.A., AmundsenL. and PedersenA.S.2016. Signal apparition for simultaneous source wavefield separation. Geophysical Journal International206, 1301–1305.
    [Google Scholar]
  35. SchonewilleM., DishbergerD. and KapadiaD.2014. Comparison of 3D time‐domain radon and matching‐pursuit Fourier interpolation. 84th SEG annual international meeting, Denver, Expanded Abstracts, 3605–3609.
  36. SchonewilleM., KlaedtkeA. and VignerA.2009. Anti‐alias anti‐leakage Fourier transform. 79th SEG annual international meeting, Houston, Expanded Abstracts, 3249–3253.
  37. SouthallB.L., BowlesA.E., EllisonW.T., FinneranJ.J., GentryR.L., GreeneC.R.et al. 2007. Marine mammal noise exposure criteria: initial scientific recommendations. Aquatic Mammals33, 411–522.
    [Google Scholar]
  38. VassalloM., ÖzbekA., ÖzdemirK. and EggenbergerK.2010. Crossline wavefield reconstruction from multicomponent streamer data: part 1 – multichannel interpolation by matching pursuit (MIMAP) using pressure and its crossline gradient. Geophysics75, WB53–WB67.
    [Google Scholar]
  39. ZiolkowskiW.M., ParkesG.E., HattonL. and HauglandK.1982. The signature of an air gun array: computation from near‐field measurements including interactions. Geophysics47, 1413–1421.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1111/1365-2478.12708
Loading
/content/journals/10.1111/1365-2478.12708
Loading

Data & Media loading...

  • Article Type: Research Article
Keyword(s): Acquisition , Imaging and Seismics
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error