【作者】 勾丽敏；

【导师】 刘学伟；

【作者基本信息】 中国地质大学（北京） ， 地球探测与信息技术， 2007， 博士

【摘要】 散射波地震方法是针对隐伏金属矿、构造或岩性复杂区油气勘探等复杂勘探对象提出的,是基于地震波散射理论使用更广义的散射波描述多种尺度非均匀地质体形成的复杂地震波场的勘探方法,其理论与应用技术研究是目前地震勘探领域内的一项前沿课题。其中,散射波成像处理技术是关系到散射波地震方法能否由理论步入实际生产的关键应用技术之一,系统地研究这项技术具有重要的现实意义和广泛的实用价值。论文主要研究内容与结论如下:1.从分析散射波和反射波的区别入手,指出散射波地震资料处理中存在静校正、提高信噪比和分辨率、准确速度估计和偏移成像等处理难点,而散射波成像处理技术是目前散射波勘探最迫切的应用技术需求。2.根据散射波的运动学特征,提出散射波速度分析方法,并利用一系列典型地质模型的正演数值模拟数据系统地研究了散射波速度分析方法的适用条件。研究表明某一点的散射波速度就是将其上的散射波传播介质空间看作均匀介质,用双曲线来描述散射波时距关系时的速度。常速均匀介质中散射点源的散射波速度即为介质速度;当地下为水平层状地层时,散射波速度就是均方根速度,也等价于叠加速度;当地下为倾斜地层时,散射波速度就是消除倾角效应的介质速度,也是DMO处理所需要的初始速度。相对于反射波速度分析方法,散射波速度分析方法在含有突变点、陡倾角界面、小尺度地质体等复杂构造地质条件下更具优势,有利于得到更精确的散射波速度,改善偏移成像效果。3.提出了基于共散射点道集的偏移方法,并对Kirchhoff叠前时间偏移等生产中常用偏移方法对散射波的适用性进行研究。在使用散射波速度场的前提下,反射波叠前时间偏移成像方法可直接用于散射波成像,反射波叠后偏移方法用于散射波成像的前提条件是通过DMO或者共散射点道集叠加来获得自激自收叠加剖面。4.结合物理模拟和实际地震资料,对振幅补偿、静校正、噪声衰减和反褶积等常规反射波方法在散射波成像处理中的应用策略进行了研究。研究表明静校正、噪声衰减、反褶积等反射波方法可直接用于散射波资料处理。5.通过实际处理效果分析,讨论了利用反射波成像技术进行散射波成像处理的利弊、散射波成像处理技术的优势,并初步总结出散射波成像处理技术与流程。更多还原

【Abstract】 Scattering seismic exploration method is brought forward for complex targets, such as buried metal mine and energy sources trapped in complex structural or lithologic area. It is a new approach which uses generalized scattered wave to describe complex seismic wavefield generated by heterogeneous bodies with a variety of sizes based on seismic wave scattering theory. The theoretical and applied technique investigations of scattering seismic exploration method are one of the leading edge problems in the field of seismic prospecting. Scattered imaging technique is one of the most important applied technique for the method to step into practice. Thus, to study such imaging technique systemically has wide and practicable value in complicated heterogeneous bodies prospecting.The main contents and conclusions in the article are as follows:First, the article has analyzed the differences between reflected wave and scattered wave in detail, and pointed out that the static correction, signal-to-noise ratio and resolution enhancement, accurate velocity inversion and imaging are the main difficulties for scattered data processing, and that associated imaging technique is the exigencies of scattering seismic exploration method.Second, the article has studied the scattered velocity analysis method based on kinematical features of scattered wave, and studied systematically the range of application of the method using a series of typical models and their numerical modeling data. The results have shown that scattered velocity from a scattered point source is equal to the velocity when it is assumed that the medium above is homogeneous and scattered wave travel-time curve is hyperbola. Therefore, the scattered velocity of a scattered point source in homogeneous medium with constant velocity is the medium velocity; that of the horizontal layers is root-mean-square velocity or stacking velocity, and that of the tilted layers is medium velocity with the dip effect having been removed, which is also the input velocity for dip moveout correction. Compared with reflection method, the scattered velocity analysis approach is well suited to handle complex geology in acquiring more accurate velocity to improve image, characterized by discontinuities, steep dipping beds, small scale geologic bodies.Third, the paper has presented a new migration method based on common scattered pointgathers, and studied other three widely used reflection imaging methods. With the scattered wave velocity field, the pre-stack time migration methods of reflection survey can be used in scattered seismic data processing directly, whereas the post-stack ones can be used on the precondition of using DMO or common scattered point gathers stack to get stacked sections.Fourth, the paper has studied the application strategy of common reflection processing methods in scattered data imaging processing, including amplitude correction, static correction, noise removing, and deconvolution, using physical modeling and field seismic data. The result has revealed that these methods can be used to process scattered data directly.Fifth, the article has also discussed the advantages and disadvantages of using reflection imaging technique to process scattered data and the advantages of scattered imaging technique. Moreover, the scattered imaging technique and processing flow have been summarized.更多还原