Efficient design of air-gun arrays
M. H. Safar
Journal name: Geophysical Prospecting
Issue: Vol 24, No 4, December 1976 pp. 773 - 787
Info: Article, PDF ( 817.7Kb )
A new technique is developed for shaping the pressure bubble pulse radiated by an array of air-guns. It involves the proper spacing of identical units. It is shown that considerable shortening of the pressure bubble pulse can be achieved provided there is sufficient mutual coupling between all the air-guns.
The existing air-gun array technique for reducing the bubble pulse involves the redistribution of the energy of the bubble pulses which are produced by an array of variable sized air-guns such that no energy of the bubble pulses is radiated along the perpendicular to the array axis and only the sum of the initial pulses produced by the air-guns forming the array is radiated along that direction. However, the new air-guns array technique involves the damping of the bubble pulses which are produced by an array of identical air-guns by means of mutual interaction and the effective pressure pulse radiated by the array is given by the sum of the damped bubble pulses produced by the mutually coupled identical air-guns.
Preliminary field trials gave results consistent with the theoretical predictions. A comparison between the waveforms of the pressure bubble pulses radiated by a single air-gun and by an array of four identical air-guns shows that, due to the presence of mutual coupling between the four air-guns, effective damping of the bubble pulse radiated by the array is about 50% greater than that of the bubble pulse radiated by the single air-gun.