深水区直达波子波提取气泡效应压制技术

海洋地震勘探中最常用的空气枪震源激发时，将高压空气在瞬间注入水中，所形成气泡在水中发生膨胀与收缩，形成气泡效应，这种气泡效应会严重影响地震资料的分辨率和信噪比。实际海上勘探中是由多个不同容量气枪同步激发，其主脉冲因相干而增强，而气泡效应则因不同步而被抑制。但因地层的吸收作用，主脉冲迅速衰减，气泡效应逐渐凸显出来，尤其会严重影响深部地层成像。分析研究认为，深水地区直达波直接记录了采集施工的子波形态；利用从直达波提取的子波对数据进行确定性子波反褶积处理，可有效地压制气泡效应。经实际资料验证，气泡效应压制效果良好，且压制过程能“保真保幅”。

De-bubble based on wavelet extraction from direct wave in deep water

The air gun array is the main source in marine seismic exploration.When air gun is working, high pressure air is injected into the water in a very short moment.Air bubble will swell and shrinkage in water, which is called bubble oscillation effect.The bubble affects seismic data signal-to-noise ratio (SNR) and resolution.Usually a few air guns with different capacity (air gun array) are working at same time during acquisition, so the main pulse is enhanced due to coherence, and the bubble is inhibited due to asynchronization.However, the main pulse damps rapidly because of strata absorption, and the bubble effect is gradually highlighted, which brings serious problems to deep layer imaging.Therefore we propose a de-buble method based on wavelet extraction from direct wave in deep water.As the direct wave in deep water area includes source wavelet, we first extract wavelet from direct wave, then perform deterministic wavelet deconvolution to suppress bubble effects.Tests on real data show the proposed method can not only suppress bubble effects but also preserve the amplitude.