反射波地表一致性相位校正
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摘要
地震叠加技术能提高资料的信噪比，其假设条件是在NMO校正后的CMP道集内进行地 震道同相叠加。在叠加剖面上，地震子波的相位不是简单的数量相加，而是矢量求和，因此 在叠加前，不但要对所有地震道进行振幅、时间校正，而且还要进行相位校正，以使叠加 前CMP道集内所有地震道的振幅、时间和相位保持一致。只有这样才能得到最好的叠加效果 。根据该假设条件，通过炮集、检波点集之间的迭代计算得到最佳相位校正因子，以实现 相位校正。在地表一致性相位校正之后，尽可能地使得叠加前CMP道集上的地震波形对齐， 即相位一致，通过叠加可得到最佳叠加剖面。本文采用变相位校正方法实现相位校正。 通过实际数据试算，验证了本方法的正确性。
The stack can improve signal to noise ratio of seismic section,but hypothetic al condition is that the traces on the gather stack in phase after NMO.The phase of seismic wavelet is not simply quantitative add but vectorial add on stack se ction,so not only must make correction for amplitude and time on all seismic tra ces but also for phase before stack in order to that amplitude,time and phase of all seismic traces on a gather remain consistency before stack.Only doing so ca n get best stacking results. According to surface consistent hypothesis and th rough iterative calculation between shot set and receiver set,the optimal phase correcting factor can be determined which realized phase correction .After surface consistent phase correction,the seismic waveform can be align ed and phase can be consistence in maximum possibility on CMP gather and optimal stack section can be made after stack.We use variable phase correction to reali ze phase correction.The real data test showed the correctness of the method.
The stack can improve signal to noise ratio of seismic section,but hypothetic al condition is that the traces on the gather stack in phase after NMO.The phase of seismic wavelet is not simply quantitative add but vectorial add on stack se ction,so not only must make correction for amplitude and time on all seismic tra ces but also for phase before stack in order to that amplitude,time and phase of all seismic traces on a gather remain consistency before stack.Only doing so ca n get best stacking results. According to surface consistent hypothesis and th rough iterative calculation between shot set and receiver set,the optimal phase correcting factor can be determined which realized phase correction .After surface consistent phase correction,the seismic waveform can be align ed and phase can be consistence in maximum possibility on CMP gather and optimal stack section can be made after stack.We use variable phase correction to reali ze phase correction.The real data test showed the correctness of the method.
引文
[1]周兴元. 常相位校正. 石油地球物理勘探,1989,24(2):119～129
[2]李庆忠. 走向精确勘探的道路,石油工业出版社,1994
[3]Ibrahim Palaz. 碳酸盐岩地震学,中国石油学会物探专业委员会,1998
[2]李庆忠. 走向精确勘探的道路,石油工业出版社,1994
[3]Ibrahim Palaz. 碳酸盐岩地震学,中国石油学会物探专业委员会,1998
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