单道地震资料处理方法研究及其在平潭海域的应用-海洋地质专业论文.docxVIP

3）提取的地震子波与反射波的相关性强，而与其它干扰波的相关性弱，因 此可以利用提取的地震子波进行相关滤波，提高地震记录的信噪比。进行相关滤 波时，相关子波长度不宜超过地震子波的延时。而相关滤波前对地震记录先进行 带通滤波能够有效地克服低频水波干扰对相关处理的影响。 地震资料解释通常需要结合地质钻孔、地球物理测井等资料。利用测线附近 取得的钻孔沉积物样品的分析测试结果，对沉积层序进行划分，根据以往经验， 沉积物声速设为 1600m/s，将柱状样长度转换为地震波旅行时，与处理后的时间 剖面进行对比，并结合反射同相轴的接触关系，识别出 4 个主要反射界面。 关键词：单道地震；背景噪声；子波提取；相关滤波； Abstract High resolution single channel seismic exploration is one of the essential methods to detect shallow stratum structures, active faults and also the potential geohazards under seabed. It is widely used in marine geological surveys and offshore site investigations. During the data acquisition stage of marine single channel seismic exploration, the seismic source and hydrophones are placed underwater and towed by the research vessel, seismic waves are produced by the source at fixed time interval and each seismic trace is recorded while the vessel navigating with a constant speed. Many kinds of interference may exist in single channel seismic record, such as multiple, ghost reflection, ambient noise, etc., and these interference will influence seismic data interpretation. Hence, understanding the causes and propagation rules of the interference will be helpful in improving seismic data processing. This thesis first introduces several methods of marine seismic exploration, sparker sources and hydrophone array usually used in marine single channel seismic exploration and also the familiar interference in single channel seismic record. And then based on the survey data of Ping-tan sea, spectral filtering according to the analysis result of background noise and extracting seismic wavelet from direct wave and correlation filtering utilized the seismic wavelet. Last but not least, partition seismic sequence according to the analysis result of nearby core sediment. Following are three main cognitions from this thesis: First of all, marine seismic exploration is based on research vessel, noise produced by vessel machineries(include propulsion motor, propeller, electric