双检波器保幅偏移成像影响因素分析研究

发布时间：2018-02-26 13:12

本文关键词： 双检真振幅偏移算法检波器不一致性构造速度模型误差　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：基于反射波的地震勘探技术以研究地下地质构造、反演地层岩性参数为主要目标。地震偏移技术是反射地震数据处理中的核心技术之一,其中波动方程叠前深度偏移为复杂地质构造成像提供精确的成像手段。而随着目前油气勘探的需求量越来越大,油气勘探的难度加深,传统的偏移方式难以满足日益提高的要求。勘探的精确性在地震勘探技术中占据越来越重要的地位。偏移处理曾经只关注于构造形态偏移的精确性,而近来发展到偏移后能否反映构造界面处的真实振幅。也就是说,人们开始不仅关注地下构造形态及位置,也关注地下构造岩性是如何变化的;人们开始不仅只利用反射地震资料中的运动学信息,也开始利用动力学信息进行地震资料处理。对于叠前深度偏移处理来说,大部分深度外推偏移算法都是基于单程波方程,单程波方程对于反射界面的真振幅估计具有先天不足,而真振幅对于AVO反演具有重要意义。因此,本文使用的一种基于上下检波器的全声波方程深度偏移方法,该算法可以准确求解波动方程,从而提供更加准确的反射界面动力学信息。本文就是基于该套全新的双检波器地震数据采集系统及其双检谱投影真振幅偏移算法(JiachunYou,2015),提出并测试在非理想的实际情况下,该算法的稳定性与可靠性,即“鲁棒性”。实际生产中地震数据的误差不可避免且来源有很多。在采集过程有检波器之间固有的不一致性误差,各种随机噪声误差;在地震资料处理过程中,有速度模型不精确带来的误差;更有构造本身对地震波能量的具有不同的反射作用,从而不能完全通过偏移达到绕射点归位的效果。同时,不同的地质构造对于偏移中速度误差容忍度和敏感度也是不相同的。通过对这些可能出现的误差进行模拟分析,其目的是为双检波器谱投影算法的实际应用提供可靠的理论基础,并为后续深入研究提供思路。
[Abstract]:Seismic exploration technology based on reflection wave is aimed at the study of underground geological structure and inversion of strata lithologic parameters. Seismic migration is one of the core techniques in seismic reflection data processing. The wave equation prestack depth migration provides an accurate imaging method for the imaging of complex geological structures. However, with the increasing demand for oil and gas exploration, the difficulty of oil and gas exploration becomes more and more serious. The accuracy of exploration plays an increasingly important role in seismic exploration technology. Migration processing only focused on the accuracy of structural migration. Whether the true amplitude of the tectonic interface can be reflected after the recent migration, that is, people begin to pay attention not only to the shape and location of the underground structure, but also to how the lithology of the underground structure changes; For prestack depth migration, most depth extrapolation migration algorithms are based on one-way wave equation. One-way wave equation is inherently deficient for true amplitude estimation of reflection interface, and true amplitude is of great significance for AVO inversion. Therefore, this paper uses a full acoustic equation depth migration method based on upper and lower geophone. This algorithm can solve the wave equation accurately. Based on the new seismic data acquisition system of double geophone and its true amplitude migration algorithm JiachunYou2015, this paper presents and tests the dynamic information of reflection interface. The stability and reliability of the algorithm, that is, "robustness", is inevitable and there are many sources of seismic data errors in actual production. There are inherent inconsistency errors between geophone and random noise errors in the acquisition process. In the process of seismic data processing, there are errors caused by imprecise velocity models, and the structures themselves have different reflection effects on seismic wave energy, so they can not completely achieve the effect of diffraction point homing through migration. At the same time, Different geological structures have different tolerance and sensitivity to velocity error in migration. Its purpose is to provide a reliable theoretical basis for the practical application of the spectral projection algorithm of the double geophone and to provide a train of thought for further research.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P631.4

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