A Technique for Suppressing Bubble Oscillations from an Air Gun during Shallow-Water Marine Seismic Surveying

Abstract

Non-explosive sources have become widespread. Along with electric spark and electrodynamic sources, which are used mainly in works on the upper part of a section, these include pneumatic sources. This type of source meets all the requirements for geophysical equipment. The main problem of such sources is the presence of intense pulsations and the long duration of the emitted signals, as well as the poor reliability of some clusters. The problem of pulsations during shallow water acquisitions is especially topical. The depth of shallow water does not allow one to extract a signature that is acceptable for the construction of an effective operator from the data due to the interference of pulsations from the direct wave with the bottom, while the suppression operator that is extracted from the theoretical signature often gives an unacceptable result. To solve bubble oscillation problems in shallow-water acquisition it is proposed to use combined information from bubble oscillations extracted from a direct wave, extracted from bottom reflections, waveform predicting deconvolution, and adaptive subtraction algorithms.