地表一致性表层相对Q计算及补偿方法研究与应用

摘要

地表介质疏松，地层品质因子Q小，地震波的高频成分经地表传播后衰减严重。常规处理方法通过地表一致性反褶积和地表一致性振幅校正补偿地震数据频率和振幅，对地震子波相位变化不能正确校正。新方法通过使用表层旅行时和地表一致性相对振幅系数计算表层相对Q值，结合带增益控制的稳健Q补偿方法补偿表层地震波的衰减，可同时补偿表层引起的地震子波振幅、相位和频率变化。理论模型试验表明，表层Q补偿后的数据较常规反褶积数据的时域数据特征与原始反射系数特征更吻合，证明其振幅保真性更好。实际数据应用表明地震数据分辨率得到提高。%Near-surface is featured with porous medium, and formation quality factor Q is small, so the high-frequency components of seismic wave attenuate seriously after transmission via the earth's surface. Conventional method can com-pensate amplitude and frequency of seismic data by surface-consistent deconvolution and surface-consistent amplitude correction, but can't correct wavelet phase rightly. New method with near-surface travel time and surface consistent rela-tive amplitude coefficient to calculate Q to surface, and combine with steady Q compensation technology by gain con-trolling to compensate seismic wave attenuation of near-surface. This method can compensate the change of amplitude, phase and frequency caused by near-surface for seismic wavelet. Theoretical model proved that the features of seismic data in time domain after near-surface Q compensation correlate better with raw reflection coefficient than deconvolu-tion data, so its amplitude fidelity is better. The application of real data proved that its resolution improved.