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Volume 40 Number 7
  • E-ISSN: 1365-2478

Abstract

A

In 1989 a new type of marine seismic source was introduced. This new air‐gun, which consists of two air chambers instead of one, is called the GI gun. The main feature of this gun is that the bubble created by the gun is stabilized by an injection of extra air from the second chamber at a later time. This injection mechanism reduces the amplitude of the bubble oscillations, which also means that the acoustic signal from a GI gun shot is characterized by a very clean primary pulse followed by very small bubble oscillations. A method for calculating the acoustic signal generated by a GI gun is presented. Based on the solution of a damped Kirkwood–Bethe equation, the far‐field pressure of single GI guns and of arrays of GI guns is calculated.

It is shown that the optimal values for injection start time and injection period vary with injector volume and gun depth. It is also shown that the precision in the firing time for the injector should be of the order of 4 ms, while the precision of the injection period should be of the order of 8 ms. Modelled and measured far‐field signatures have been compared, and the relative error energy is found to be less than 3.5% for all examples.

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2006-04-27
2024-04-24

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References

  1. Bornhorst, W.J. and Hatsopoulos, G.N.1967. Bubble‐growth calculation without neglect of interfacial discontinuities. Journal of Appled Mechanics34, 847–853.
    [Google Scholar]
  2. Flynn, H.G.1965. Physics of acoustic cavitation in liquids. In: Physical Acoustics1B. W.E.Mason (ed.), 265–336, Academic Press, Inc.
    [Google Scholar]
  3. Gilmore, F.R.1952. Collapse of a spherical bubble. Report no. 26‐4, Hydrodynamics Laboratory, CALTEC, Pasadena, California .
    [Google Scholar]
  4. Herring, G.1941. Office of Scientific Research and Development Report No. 236.
  5. Keller, J.B. and Kolodner, I.I.1956. Damping of underwater explosion bubble oscillations. Journal of Applied Physics27, 1152–1162.
    [Google Scholar]
  6. Kirkwood, J.D. and Bethe, H.A.1942. Office of Scientific Research and Development Report No. 588.
  7. Laws, R. M., Hatton, L. and Haartsen, M.1990. Computer modelling of clustered airguns. First Break8, 331–338.
    [Google Scholar]
  8. Parkes, G.E., Ziolkowski, A., Hatton, L. and Haugland, T.1984. The signature of an air gun array: Computation from near‐field measurements including interactions ‐ Practical considerations. Geophysics48, 105–111.
    [Google Scholar]
  9. Pickavance, P.J.1991. G.I. gun sea trials. 53rd EAEG meeting, Florence, Italy, Expanded Abstracts.
  10. Rayleigh, O.M.1917. On the pressure developed in a liquid during the collapse of a spherical cavity. Philosophical Magazine34, 94–98.
    [Google Scholar]
  11. Ziolkowski, A.1970. A method for calculating the output pressure waveform from an air gun. Geophysical Journal of the Royal Astronomical Society21, 137–161.
    [Google Scholar]
  12. Ziolkowski, A., Parkes, G.E., Hatton, L. and Haugland, T.1982. The signature of an air gun array: Computation from near‐field measurements including interactions. Geophysics47, 1413–1421.
    [Google Scholar]
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  • Article Type: Research Article

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