Air-gun bubble damping by a screen
- IKU Petroleum Research, Trondheim (Norway)
- Statoil Research, Trondheim (Norway)
A method for damping unwanted bubble oscillations from a seismic air gun is presented. The method exploits the fact that the primary pressure peak generated by an air gun is produced during the first 5--10 ms after firing. The air bubble is destroyed by mounting a perforated screen with an optimal radius about the gun. Once the primary pressure peak has been generated by the bubble, the bubble is destroyed by the screen, leading to a corresponding decrease in the measured pressure amplitude of the secondary bubble oscillations. Controlled near-field measurements of 40-cubic inch and 120-cubic inch air guns with and without damping screens are used. The primary to bubble ratio improves from 1.4 without a screen to 4.4 with a screen in the near-field. The corresponding values for estimated far-field signatures are 1.8 to 9.0 when the signatures are filtered with an out-128 Hz (72 dB/Oct) DFS V filter.
- OSTI ID:
- 175958
- Journal Information:
- Geophysics, Vol. 60, Issue 6; Other Information: PBD: Nov-Dec 1995
- Country of Publication:
- United States
- Language:
- English
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