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斜缆采集资料中鬼波的陷频特征限制了地震记录的频带宽度和分辨率,给地震资料反演、解释带来困难。通过压制鬼波,可获得高分辨率的宽频数据。基于拉东域的水平拖缆鬼波压制方法,结合斜缆鬼波随偏移距变化的特点,推导出一次波和鬼波在频率-拉东域的逆变换算子,建立检波器处总波场和海表面处上行波场之间新的关系式,利用最小二乘反演精确求解获得海表面处上行波场,并延拓得到拖缆处鬼波压制后的记录。通过考虑鬼波延迟时间受偏移距和出射角的影响,弥补鬼波延迟时间估计中存在的误差,无需进行反演迭代求取最优鬼波延迟时间,提高了计算效率。合成数据及海上实际斜缆数据测试结果表明,研究方法能较好地压制鬼波,达到拓宽地震记录频带的目的。 相似文献
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为拓宽有利于地震成像的频带范围,特别是拓宽对中深层地质构造成像有利的低频,物探工程师提出和改进了很多采集技术与方法,其中较为成功的技术是斜缆宽频采集技术,其原理是斜缆采集使得虚反射的陷波频率点不同。笔者重点分析了变深度电缆对地震资料频谱特征尤其是低频的影响,提出振幅曲线的陡度函数是测量信号在低频端丰富程度的有效方法,并通过模型正演比较了由等深的水平缆和变深度的斜缆采集的地震道频谱特征;然后针对虚反射引起的鬼波难题,采用修改的线性最小平方Radon变换方程来消除虚反射产生的鬼波,然后分别应用于正演模型和实际的南海斜缆地震资料,均取得较好的去鬼波效果。 相似文献
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鬼波衰减是深拖平缆采集资料处理中非常重要的一步,也是实现宽频处理的关键步骤。为此,笔者分析了深拖平缆资料特点,推导了鬼波的时距曲线方程,在此基础上,介绍了线性Radon域最小平方反演方法衰减鬼波的基本原理,该方法首先通过最小平方方法求得无鬼波的Radon域数据,再应用反变换算子中的一次波算子进行反变换,从而实现了对鬼波的压制。采用该理论对模型数据与实际地震资料进行了试处理,结果表明,深拖平缆资料通过本文的鬼波衰减技术处理后,陷频点得到了补偿,有效频带得到了拓宽,达到了宽频处理的效果。 相似文献
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《物探与化探》2020,(4)
西湖凹陷是东海最大的含油气凹陷,其主要储层位于中深部,埋藏较深。增加低频信息是解决西湖凹陷主要地质问题的核心之一。斜缆地震采集技术可以有效地压制鬼波,拓宽频带,尤其是低频成分,并且具有野外操作简单、成本低等优势,对解决西湖凹陷的地质问题有利。基于斜缆平均鬼波滤波特性,对斜缆缆型、沉放深度范围等关键采集参数进行了理论分析;通过二维野外试验,对不同斜缆采集模式的单炮记录、偏移剖面开展了进一步的对比研究。结论认为:对于西湖凹陷深部储层,相较于常规水平缆资料,斜缆资料的构造刻画更清楚,频带得到了一定的拓宽。常用的两种斜缆缆型中,直线型斜缆的陷波补偿效应更好,抛物线型斜缆的低频能量更强。在斜缆最浅沉放深度固定时,加大斜缆沉放深度差,有利于获取更多的低频信息。 相似文献
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《物探化探计算技术》2021,(2)
海洋拖缆地震资料中鬼波会影响地震子波的形态,不同工区之间由于炮点、检点沉放深度不一致引起的鬼波周期和形态不一致,使得不同工区子波特征存在较大差异;由于常规拼接匹配技术没有考虑鬼波差异,解决不了鬼波的周期不一致问题,拼接处往往会存在明显的拼接痕迹,达不到理想的拼接效果。这里提出基于复杂海况鬼波压制(CSDG)的不同工区间的匹配拼接技术,对不同工区分别进行源、检鬼波及气枪信号进行压制,有效地解决了不同工区间的鬼波差异的问题,并在A工区及B工区数据匹配拼接中进行了验证,实现了两个工区的叠前无缝拼接处理,改善连片处理的数据品质,为后续的地质解释和油气预测提供便利。 相似文献
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《物探与化探》2020,(1)
电火花震源是一种重要的海洋地震勘探技术装备。它不仅环保、安全、成本低,而且数据具有宽频带优势,能够实现高分辨率地震勘探。但电火花震源在发展初期,存在信号不稳定、勘探深度浅等问题,导致它的发展速度减慢而被气枪震源所取代。后来,随着电力电子技术的快速发展以及数据处理水平的提高,这些问题逐渐得到解决,近年来逐渐又引起了人们的重视。文中概括了电火花震源的硬件、数据处理方法的发展历程,总结了电火花震源发展过程中存在的问题,阐述了前人使用电火花震源地震勘探的应用效果,从数据处理角度提出了解决存在问题的方法,展望了电火花震源对于未来海洋地震勘探的前景以及发展方向,认为电火花震源在未来海洋地震勘探中将会发挥更大的作用。 相似文献
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Huai Zhang Shaolin Chen Shi Chen Si Chen Huimin Jing David A. Yuen Yaolin Shi 《Visual Geosciences》2008,13(1):117-124
Today parallel visualization of massive datasets from observation and numerical simulation of seismic waves is one of the
major goals of geoscience community. A majority of these datasets are time-varying volume data (TVVD), also known as 4D field
data. The difficulty of visualizing them on distributed parallel system mainly lies in the algorithm designing for distributed
preprocessing of raw datasets, hierarchical point-to-point or collective communication implementation based on distributed
data allocation, synchronous volume rendering techniques. In this work we present viable solutions for preprocessing of raw
data sets, novel algorithms of parallel rendering and display matrix. Our main objective is focused on the parallel visualization
of results coming from full 4D seismic wave propagation simulations. 相似文献
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The problem of automatic detection of seismic waves by large telemetered seismic networks such as the Mexican Continental Aperture Seismic Network (RESMAC), is extended here to include determination of seismic first-arrival and S-phase-arrival times. A short general outline of the detection problem background and a small introduction to the autoregressive model (AR) concept are presented. Several automatic detection algorithms were implemented and compared with a newly developed autoregressive algorithm. Careful consideration of the advantages and disadvantages of each method determined that a mixed detection scheme is optimal and suitable for RESMAC. A few examples are shown that illustrate the relative performances of the methods tried here. The proposed detection scheme has the following characteristics: (a) First-arrival detection, based on a simple (average of squared input) characteristic function, and a trigger criterion that uses as a distortion measure the long-average-to-short-average ratio of the characteristic function, checked using a duration criterion; (b) use of two threshold values, one for triggering, and another for beginning the backward search for the phase arrival time; (c) use of the autoregressive model (AR) method, with the Itakura-Saito distortion measure, for S-phase detection, checked using both duration and amplitude criteria; and (d) characterization of the reliability of the determinations for their subsequent use in automatic location programs, alarms, etc. The automatic detection scheme has proved effective. 相似文献
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地震波场数值模拟方法多种多样,各种方法都有各自的特点.这里推出一种全新地震波场模拟方法--基于Forsyte广义正交多项式的迭积微分算子法,该方法将计算数学中的Forsyte多项式,应用到地震波传播的数值模拟中,它同时具有广义正交多项式迭积微分算子的高精度和有限差分短算子算法的高速度.通过对算子长度的调节及算子系数的优化,可同时兼顾波场解的全局信息与局部信息.复杂非均匀介质模型数值模拟结果说明了该方法的可行性.将该方法的计算结果与傅氏变换伪谱法、错格高阶有限差分法相比较,结果说明,该方法在波场模拟方面具有较好的发展潜力,并具有自身独到的优越性. 相似文献
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In the case of the dynamic analysis of the structures using the recorded earthquake ground motions, it is usually assumed that the ground motion consists of body waves propagating vertically. However, the response of a long and narrow structure may be influenced by the oblique propagation of body waves and the dispersion of surface waves. In this paper, the effects of the seismic wave propagation on the response of this kind of structure are investigated. The characteristics of the wave propagation were verified using the recorded motions and soil information at the building site. The ground motion at every input point of the building was evaluated using the difference of arrival time of seismic waves calculated by assuming the velocity and the direction of the wave propagation. Using these ground motions, response analyses of the lumped mass model for the structure were performed. By considering the characteristics of the seismic wave propagation, the average response decreased but the local response increased around the end of the roof. Further studies of the structure were also performed in order to restrain the response around the end of the roof. 相似文献
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单程波法地震波衰减特征数值模拟分析 总被引:2,自引:1,他引:1
在非均匀粘弹性介质中,地震波衰减研究能够有效揭示地层吸收特性对地震波的影响。这里从单程波方程出发,结合粘弹性介质中的复波数理论,考虑介质的横向变化,采用分步傅立叶波场延拓技术,推导出适用于横向变速介质的带Q地震记录计算公式,最后将此方法应用于四个不同含Q地层模型。试验表明:单程波法计算速度快,波场信息简单清晰,易于深入分析和反演算法的建立。并且,Q值对地震波波形、能量、频率等都产生了较为明显的影响,对实际资料能量补偿、地震资料分辨率的提高,以及利用衰减特征进行储层识别有一定指导价值。 相似文献
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深水区地震波传播特性研究 总被引:1,自引:0,他引:1
根据层速度与Q值的经验公式和对射线参数进行泰勒展开的方法,以及二维有限差分声波波动方程波场数值模拟技术,为海上长排列大容量震源地震资料采集及高分辨率地震勘探野外施工的观测系统设计及数据处理方案等提供参考意见。 相似文献
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Natural Hazards - National capital of India, Delhi is under moderate to high seismic hazard due to active regional faults such as the Mahendragarh fault, the Delhi Haridwar fault, the Sohna fault,... 相似文献