时频域有色谱校正

Correction of colored spectrum in time frequency domain

江汉油田物探处计算中心, 湖北潜江 433100

Computation Center of Geophysical Prospecting Company, jianghan Oilfield, Qianjiang 433100, China

振幅谱校正是消除地震资料中非一致性的一种方法。实际生产中的几种振幅谱校正技术在应用中都存在着局限性,以致使校正过的记录不能恢复到最理想的形态。时频域有色谱校正技术可以很好地解决这一问题。其数学原理为:采用以直代曲的办法,将窄频带中振幅谱取为一常数,这样,在时域振幅谱为一冲激函数,频域的振幅谱校正可以在时域中简单实现。利用模型道法、互相关法及已知波形法给出期望的有色谱,为校正提供依据;利用小波变换的正交性来克服傅氏变换引起的频泄现象。实际资料处理表明,该方法能很好地消除地震记录中振幅非一致性问题。

Correction of amplitude spectrum is a method used to eliminate the inconsistency in seismic data. Due to limitations of methods available for correction of amplitude spectrum, the corrected records are not in their ideal wave shape. A method for correction of colored spectrum in time frequency domain is presented in the paper, provided that amplitude spectrum is constant in a narrow band and the time response of the amplitude spectrum is a spike pulse. In this case amplitude spectrum of frequency domain can be corrected easily in time domain. Colored spectrum is calculated with model method, cross correlation method, or known wave shape method. The so-called frequencyleak associated with Fourier transform is overcome with wavelet transform. Processing on real data shows that this method is able to eliminate the inconsistency in seismic data effectively.