地震异常波成像技术研究

发布时间：2018-05-23 07:04

本文选题：异常波 + 中值滤波　；参考：《西安石油大学》2017年硕士论文

【摘要】：当地下存在复杂构造的情况下,如存在尖灭点、断面、孔洞等,地震记录上会出现一类传统意义上的异常波(如断面波、绕射波等),它们是地下复杂地质构造引起的,是了解地下异常信息的有效波。然而,现有的成像技术都是将异常波与反射波同时进行成像处理,导致的结果就是地震成像分辨率降低,异常波携带的地质信息没有得到有效利用。因此,为了能充分利用这类异常波精细解决复杂地质问题,本文从异常波勘探理论出发,对地震异常波成像技术展开研究,其目的是通过异常波提取并单独成像,实现精细解决地质问题的目的。在深入分析异常波产生的原因、传播规律及地震响应特征的基础上,本文借助两组地质模型,着重开展了异常波提取、成像速度建模和偏移成像等研究工作。在异常波提取研究中,实现了中值滤波及均值滤波方法在共炮点道集、共偏移距道集及共中心点叠加剖面中提取异常波,并剖析了两种方法的可行性和有效性。在异常波偏移成像研究中,对叠前时间偏移重要参数(偏移孔径、偏移角度)进行了探究;重点开展了异常波成像速度建模研究,采用反射波速度扫描与成像速度分析相结合的方式获得初始速度模型,并进一步通过异常波同相轴拉平、精细拾取速度等手段建立异常波叠前时间偏移速度模型;建立了叠前异常波成像处理流程,通过数值模型的处理,验证了Kirchhoff叠前时间偏移成像处理的可行性。并进一步是处理了一套发育有异常波的2D实际地震资料,获得了比传统反射波法更加丰富的异常地质信息。通过反射成像与异常波成像结果联合使用,可充分利用地震波携带的信息,达到精细解决地质问题的目的。
[Abstract]:When there are complex structures in the ground, such as the existence of pinnacle, section, hole, etc., a kind of abnormal wave (such as cross-section wave, diffraction wave, etc.) appears on the seismic record, which is caused by the complicated geological structure. It is an effective wave to understand underground anomaly information. However, the existing imaging techniques are to image the abnormal wave and the reflected wave at the same time. The result is that the resolution of the seismic imaging is reduced, and the geological information carried by the abnormal wave is not used effectively. Therefore, in order to make full use of this kind of anomalous wave to solve complex geological problems, this paper, based on the theory of anomalous wave exploration, studies the seismic abnormal wave imaging technology, the purpose of which is to extract the anomalous wave and image it separately. The aim of solving geological problems in detail is realized. Based on the deep analysis of the causes, propagation rules and seismic response characteristics of abnormal waves, this paper focuses on the research work of abnormal wave extraction, imaging velocity modeling and migration imaging with the aid of two sets of geological models. In the research of anomaly wave extraction, median filter and mean filter are realized to extract abnormal wave in common shot point gather, common offset gather and common center point stack profile. The feasibility and effectiveness of the two methods are analyzed. In the study of anomalous wave migration, the important parameters of prestack time migration (migration aperture, migration angle) are explored, and the modeling of abnormal wave imaging velocity is emphasized. The initial velocity model is obtained by the combination of reflection wave velocity scanning and imaging velocity analysis, and the anomalous wave prestack time migration velocity model is further established by leveling the anomalous wave cophase axis and fine picking up velocity. The prestack anomalous wave imaging process is established, and the feasibility of Kirchhoff prestack time migration imaging processing is verified by numerical model processing. Furthermore, a set of 2D actual seismic data with abnormal waves is processed and more abundant abnormal geological information is obtained than the traditional reflection wave method. Through the combination of reflection imaging and abnormal wave imaging results, the information carried by seismic waves can be fully utilized, and the geological problems can be solved finely.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P631.4

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