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利用可控震源进行地震勘探时,通常都需要进行相关滤波,相关滤波结果的好坏取决于所选取的子波与有效反射波的相关性.海洋地震勘探常用的电火花震源激发能量通常可以调控,理论上,同一激发能量产生的震源子波应当是一致的,因此可以仿效可控震源资料的处理手段,对单道地震资料进行相关处理.但在复杂多变的海洋环境下,震源参数也要随勘探条件的变化而改变,采用理论计算或实验环境下获得的子波模型进行相关滤波往往难以达到预期的效果,需要寻找与实际勘探中激发的地震波相似度更高的地震子波.单道地震记录中直达波的能量较强,波形畸变较小,与震源子波较为接近.本文建立了一种利用直达波提取地震子波的方法,并应用到实际资料.实际资料的地震子波提取和相关滤波处理结果显示,利用直达波提取地震子波进行相关滤波能够有效地压制干扰波、突出有效波,提高了地震记录的信噪比.需要注意的是:1)提取子波的过程中要降低环境因素的影响,可利用统计平均的方法来实现;2)相关滤波时要根据实际处理效果的改善程度选择相关子波长度.
When seismic exploration is carried out by vibroseis, the correlation filtering is usually required, and the result of the correlation filtering depends on the correlation between the selected wavelet and the effective reflected wave.Generally, the excitation energy of EDM source can be regulated , Theoretically, the source wavelet generated by the same excitation energy should be consistent, so that the processing of single-channel seismic data can be followed by the processing method of vibroseis data, but in the complex and ever-changing ocean environment, the source parameters It is often difficult to achieve the expected effect by using the wavelet model obtained in theoretical calculation or experimental environment and the seismic wavelet with higher similarity with the seismic waves excited in the actual exploration needs to be found. The direct wave energy of channel seismogram is strong, the waveform distortion is small, and it is close to the source wavelet. In this paper, a method of extracting seismic wavelet by direct wave is established and applied to actual data. The actual data of seismic wavelet Extraction and correlation filtering results show that the use of direct wave extraction seismic wavelet correlation filtering can effectively suppress the interference wave Highlighting the effective wave and improving the signal-to-noise ratio of the seismic record.It should be noted that: 1) the extraction of the wavelet process to reduce the impact of environmental factors, statistical averaging method can be used to achieve; 2) The degree of improvement of the treatment effect selects the relevant wavelet length.