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胜利探区基于最优孔径的共反射面元(CRS)叠加的成功应用(英文) 总被引：1，自引：1，他引：0
由于CRS叠加考虑了反射层的局部特征和第一菲涅耳带内的全部反射,从而更充分地利用了多次覆盖反射数据的信息。就目前的地震资料处理技术而言,它是最佳的零偏移距成像方式。本论文利用改进型的参数优化技术,得到高质量的CRS运动学参数剖面,并利用参数剖面计算出叠加孔径,实现了基于最优孔径的CRS叠加,使CRS参数的用途得到了充分利用。模型数据和实际资料的试算表明,基于最优孔径的CRS叠加的成像剖面与传统CRS叠加剖面相比,有着较高的信噪比和同相轴的连续性。 相似文献
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针对复杂地表地质条件下地震资料覆盖次数不均、部分数据缺失而导致的地震资料品质下降、陡倾角地区成像质量变差等问题,文中采用了叠前三维共反射面叠加技术.共反射面叠加是一种与宏观速度无关且考虑了反射点曲率的地震成像方法.它利用共反射点道集一个邻域内(菲涅尔带)道之间的相关性,并将相干区域内道集的能量相加来增强地震反射信号和绕射波能量,并借助于相邻CMP道集数据形成CRS超道集,使得面元内的覆盖次数更加均匀;同时利用超道集的高覆盖次数来压制噪声,最终得到高信噪比道集数据.实际地震资料处理表明,该方法可大幅度地提高地震资料信噪比和分辨率,增强地震同相轴的连续性,此外还可为叠前偏移成像处理、AVO属性分析、叠前地震反演等提供高质量的输入数据. 相似文献
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本文对共反射面元(CRS)叠加方法做改进,利用得到的波场参数来提高叠前地震资料的质量.利用CRS波场参数做部分CRS叠加,对菲涅尔带内的多个相邻CMP道集做倾角、曲率等校正后合并为一个道集即CRS超道集,可以补齐缺失地震道,实现叠前数据规则化,并提高信噪比.从而使得叠前道集中的同相轴尤其是来自深层的反射有更好的连续性,有利于识别和追踪.提高质量后的叠前道集可用于后续的速度分析、叠加、偏移等常规处理中,效果好于原始CMP道集.模型和实际数据的计算结果验证了该方法的正确性和有效性.该方法在低信噪比资料的处理中将会有广阔的应用前景. 相似文献
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共反射面元（CRS）叠加考虑了反射层的局部特征和第一菲涅耳带内的全部反射,更充分挖掘了多次覆盖数据的潜力.但在地下介质复杂并存在倾斜层时存在反射点分散的情况,从而影响了CRS叠加效果.本文从射线理论出发,在考虑反射层局部特征的情况下,推导了水平地表和起伏地表情况下计算真实反射点分散程度的公式,最终将反射点分散程度定量表达出来.通过对反射点分散程度的控制,从CRS道集中抽取出共反射点（CRP）道集,在CRP道集中而不是在CRS道集中实现叠加,其效果应比传统的CRS叠加效果要好.利用水平地表和起伏地表的模型验证了本文所推导的公式的正确性和有效性.该公式在实际资料处理中的运用尚待进一步研究. 相似文献
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常规叠加方法假设叠加的地震道集的反射波来自地下同一个反射点,而地表观测到 的反射波场在空间上小于菲涅尔体范围是不可分辨的. 本文根据火山岩体特征,用元弧描述 火山岩的反射界面. 将来自菲涅尔体范围内的反射波沿着元弧界面求和,进而扩大叠加次数 ,达到增加反射信号能量提高地震反射波的叠加成像质量的目的. 文中给出了反射波走时参 数与地下元弧反射界面之间的联系和叠加实现的步骤. 计算结果表明,元弧叠加方法能够提 高剖面的信噪比,增加反射波同相轴的连续性. 相似文献
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共反射面元叠加的实现途径及流程 总被引：13，自引：3，他引：10
共反射面元叠加的思路是借助于相近共反射点道集之间的相似性,在相应的相干区内依据相邻CMP数据所生成的超CMP道集,凭借其高覆盖次数自身所具有的压制噪音功能,可大幅度地提高地震资料信噪比和分辨率．近年来。这一思路已在国内外受到广泛重视,并被视为今后深层地震资料处理方法的重要发展途径;然而已有的共反射面元叠加方法需要通过相干优化以确定所必需的三个属性参数,致使计算量甚大,且仅局限于小炮检距．为了克服这些不足,本文提出了基于速度深度模型的CRS叠加方法及流程,理论模型验证表明,本文的方法能够提高剖面的信噪比,增加反射波同相轴的连续性． 相似文献
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《地球物理学进展》2015,(4)
水平叠加技术是提高地震资料的信噪比和分辨率的方法之一.只有当CMP道集同相轴校齐,消除各种时差,才能实现CMP道集中各道真正的同相位叠加,否则地震资料的高频信息会缺失,降低信噪比和分辨率.本文给出一种应用相位替换的处理方法消除CMP道集中的剩余时差,利用消除剩余时差后的CMP道集进行叠加.这种方法的理论基础是地震信号的到达时完全包含在信号的相位谱中,通过改变相位谱可以达到改变信号到达时的目的.综合理论模型和实际资料的数据处理,详细探讨了该方法对提高信噪比和分辨率的效果,结果表明,通过选取合适的参考道,该方法可有效地提高地震资料的信噪比和分辨率且理论上可以消除任何时差. 相似文献
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在地表地形复杂的情况下,静校正不易做好,这是制约山地资料处理质量的一个很重要的因素.复杂地表共反射面元（CRS）叠加不需对叠前数据做静校正,而且在得到叠加剖面后可以利用叠加得到的波场参数剖面实现基准面重建.地震数据的试算表明,复杂地表CRS叠加得出的剖面与常规处理剖面相比有着较高的信噪比和同相轴连续性.与水平地表CRS叠加不同的是,在复杂地表CRS叠加的时距公式中,波场三参数耦合,难以通过简化CRS道集的方法将它们全部分离并逐个优化.引入模拟退火算法后,有效地解决了这一组合优化的难题. 相似文献
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Bergler Steffen Duveneck Eric Höcht German Zhang Yonghai Hubral Peter 《Studia Geophysica et Geodaetica》2002,46(2):165-175
The finite-offset (FO) common-reflection-surface (CRS) stack has been shown to be able to handle not only P-P or S-S but also arbitrarily converted reflections. It can provide different stack sections such as common-offset (CO), common-midpoint (CMP) and common-shot (CS) sections with significantly increased signal-to-noise ratio from the multi-coverage pre-stack seismic data in a data-driven way. It is our purpose in this paper to demonstrate the performance of the FO CRS stack on data involving converted waves in inhomogeneous layered media. In order to do this we apply the FO CRS stack for common-offset to a synthetic seismic data set involving P-P as well as P-S converted primary reflections. We show that the FO CRS stack yields convincing improvement of the image quality in the presence of noisy data and successfully extracts kinematic wavefield attributes useful for further analyses. The extracted emergence angle information is used to achieve a complete separation of the wavefield into its P-P and P-S wave components, given the FO CRS stacked horizontal and vertical component sections. 相似文献
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Hermann A. Buness Hartwig von Hartmann Hanna‐Maria Rumpel Charlotte M. Krawczyk Rüdiger Schulz 《Geophysical Prospecting》2014,62(3):443-452
Cost reduction in seismic reconnaissance is an issue in geothermal exploration and can principally be achieved by sparse acquisition. To address the adherent decrease in signal/noise ratio, the common‐reflection‐surface method has been proposed. We reduced the data density of an existing 3D dataset and evaluated the results of common‐reflection‐surface processing using seismic attributes. The application of the common‐reflection‐surface method leads in all cases to an improvement of the signal/noise ratio. The most distinct improvement can be seen in the low fold regions. The improvement depends strongly on the midpoint aperture, and there is a tradeoff between reflector continuity and horizontal resolution. If small scale targets are to be imaged, a small aperture size is necessary, which may be far below the Fresnel zone for a specific reflector. The substantial reduction of the data density leads in our case to an irrecoverable information loss. 相似文献
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提高地震剖面的信噪比和分辨率始终是地震数据处理中研究的重要内容.在动静校正后的同一道集内振幅和相位相同的假设条件下,地震叠加技术能明显提高资料的信噪比.实际资料中相位差问题是影响有效反射信号实现同相叠加的重要因素之一.相位校正技术能够消除子波的相位谱差异,使子波接近或达到零相位,从而达到提高叠加剖面质量的目的.对相位校正的国内外研究现状,影响相位变化的因素,相位校正的方法原理以及判别准则进行了系统的总结和概述.通过分析总结得出:随着勘探形势的发展,地震资料中的相位问题将越来越受到人们的关注和重视,对相位的研究也将成为今后的攻关课题和研究热点. 相似文献
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在地震勘探中,地形起伏和近地表速度的剧烈变化会导致地震波旅行时的扰动,通常会通过折射波信息来估算和消除这些扰动.本文在虚折射的基础上提出了逆虚折射干涉法,通过虚折射波场和原始折射波场的互相关,并对所有位于固定相位点上的检波点进行叠加,重构出逆虚折射波场.通过逆虚折射与超级虚折射的叠加,保证了不同偏移距下折射波振幅恢复的一致性,显著提高折射波的信噪比,有效提取弱信号.同时,本文采用反褶积干涉法来压制由于互相关和褶积产生的子波旁瓣的影响,弥补低频和高频能量的损失,改善恢复的折射波场的稳定性和分辨率.该新方法不需要知道近地表复杂速度模型的信息,可以将虚折射的勘探孔径恢复到原始地震记录的最大孔径.合成资料和实际资料的计算结果表明,基于反褶积的逆虚折射干涉法能够从低信噪比的资料中,有效恢复出折射波信息. 相似文献
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未偏移地震剖面的空间分辨力研究通常采用第一菲涅尔带的解释方法,它是以几何地震学的射线理论为基础,仅考虑了地震波的运动学特征,不能详细描述地震波的动力学特征.本文从物理地震学的广义绕射叠加观点出发,综合分析地震波的运动学和动力学特征,由绕射叠加效应推导出了零炮检距地震道空间分辨力的计算公式.该公式的计算结果与第一菲涅尔带半径在数值上相当,并通过正演模拟验证了计算公式的合理性.因此利用物理地震学的原理研究地震勘探空间分辨力更符合地震波客观实际的传播特征. 相似文献
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J.F.B. Bolte 《Geophysical Prospecting》2004,52(6):523-534
The common focal point (CFP) method and the common reflection surface (CRS) stack method are compared. The CRS method is a fast, highly automated procedure that provides high S/N ratio simulation of zero‐offset (ZO) images by combining, per image point, the reflection energy of an arc segment that is tangential to the reflector. It uses smooth parametrized two‐way stacking operators, based on a data‐driven triplet of attributes in 2D (eight parameters in 3D). As a spin‐off, the attributes can be used for several applications, such as the determination of the geometrical spreading factor, multiple prediction, and tomographic inversion into a smooth background velocity model. The CFP method aims at decomposing two‐way seismic reflection data into two full‐aperture one‐way propagation operators. By applying an iterative updating procedure in a half‐migrated domain, it provides non‐smooth focusing operators for prestack imaging using only the energy from one focal point at the reflector. The data‐driven operators inhibit all propagation effects of the overburden. The CFP method provides several spin‐offs, amongst which is the CFP matrix related to one focal point, which displays the reflection amplitudes as measured at the surface for each source–receiver pair. The CFP matrix can be used to determine the specular reflection source–receiver pairs and the Fresnel zone at the surface for reflection in one single focal point. Other spin‐offs are the prediction of internal multiples, the determination of reflectivity effects, velocity‐independent redatuming and tomographic inversion to obtain a velocity–depth model. The CFP method is less fast and less automated than the CRS method. From a pointwise comparison of features it is concluded that one method is not a subset of the other, but that both methods can be regarded as being to some extent complementary. 相似文献
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TH.C. KREY 《Geophysical Prospecting》1987,35(2):135-147
Three-dimensional seismic surveys, in general, do not need the same high degree of CDP coverage as 2-D surveys to achieve a certain signal-to-noise ratio after migration. This can be shown theoretically for Kirchhoff migration and laterally uncorrelated noise. More precisely, there exists a formal relationship between the multiplicity of CDP coverage of a 3-D survey and that of a 2-D survey with the same signal-to-uncorrelated-noise ratio. Frequency and aperture are parameters in the corresponding expression. Heuristically the relationship can be obtained by applying the concept of the Fresnel zone. Though the mathematics in this paper refer to laterally uncorrelated noise, the underlying concepts can probably also be used for weakly correlated noise, e.g., for multiple reflections and for the low-frequency remnants of surface waves. 相似文献
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Common reflection surface stack using dip decomposition for rugged surface topography 总被引：1，自引：0，他引：1
We present an extension of the Common Reflection Surface （CRS） stack that provides support for an arbitrary top surface topography. CRS stacking can be applied to the original prestack data without the need for any elevation statics. The CRS-stacked zero- offset section can be corrected （redatumed） to a given planar level by kinematic wave field attributes. The seismic processing results indicate that the CRS stacked section for rugged surface topography is better than the conventional stacked section for S/N ratio and better continuity of reflection events. Considering the multiple paths of zero-offset rays, the method deals with reflection information coming from different dips and performs the stack using the method of dip decomposition, which improves the kinematic and dynamic character of CRS stacked sections. 相似文献