Radon变换多次波压制方法及应用研究

多次波在地震资料中是普遍存在的。Radon变换是现行商业地震资料多次波压制处理软件应用最多的模块之一。这里在详细阐述Radon变换基本原理和离散采样计算的基础上,给出了理论模拟地震数据的多次波压制算法和计算结果。进而将Radon变换多次波压制方法应用于松辽盆地地震资料处理中,在对实际的CRP道集合理设计滤波切除函数后,应用本文的Radon变换算法,得到多次波压制的地震剖面。对比多次波压制前、后的叠前时间偏移地震剖面,压制多次波后地震剖面的信噪比很高,地质构造特征清晰,可应用于后续的地质构造解释,地震属性提取和油气储层预测。该方法的计算效率较高,算法易于实现。理论和实际地震数据的多次波压制结果表明,该算法具有高精度和实用性强的特点。     

基于稀疏反演算法的高分辨率Radon变换及其在多次波压制中的应用

针对目前双曲Radon变换Radon域能量团能量泄漏的问题,提出一种基于稀疏约束反演算法的高分辨率Radon变换进行多次波的压制. 该方法在常规双曲Radon变换的基础上加入稀疏约束条件,应用共轭导向梯度( CGG)反演算法进行求解,能有效地提高Radon域速度谱的聚焦效果,有利于分离一次波和多次波. 模型和实际资料试算证明了该方法的有效性和实用性.     

压制噪声的高分辨率Radon变换法

Radon变换在地震处理中有诸多应用,在地震同相轴识别和估计方面有良好效果。对最小平方意义下反演和基于贝叶斯原理的稀疏约束反演的Radon变换域结果进行了对比,后者的变换效果更好,收敛能量的分辨率高,即压制了离散运算中的截断效应。又通过加噪模型数据,对比了高分辨率Radon变换方法和Radon域内的二维蒙版滤波方法,两者压制规则干扰和随机噪声的效果较好并且结果相似,但后者计算效率较高。在实际数据处理中,比较了FK滤波、高分辨率线性和抛物线Radon变换,以及二维蒙版滤波方法的去噪效果和计算效率,选择二维蒙版滤波方法最优。     

基于低频约束的高分辨率Radon变换多次波压制方法研究

抛物线Radon变换是地震资料处理中常用的一种多次波压制方法,常规Radon变换由于采用最小二乘算法的原因,对不同的曲率值采用相同的加权值进行求解,分辨率较低。为提高Radon域数据的分辨率,应采用对不同曲率值应用不同的加权值的方法。一般的思路是利用前一次迭代的结果得到加权矩阵,该算法需要迭代进行,运算量较大。这里拟采用低频约束的方式提高Radon变换的分辨率,即利用前一个频率的运算结果对下一个频率的计算进行约束,该算法分辨率高,计算速度快。模拟数据和实际数据的测试表明,本文方法在多次波压制处理中,可以快速有效地完成多次波去除。     

S变换和TT变换联合压制地震面波

TT变换(Time-Time transform)是基于S变换的一种新的非平稳信号处理方法,具有很好的频率聚集能力.面波的频率比反射波的频率低,通过提取TT变换域的对角线元素,就可以压制低频面波.但该方法的不足是在压制低频的同时,也保留了部份高频干扰,这些高频干扰可以用S变换来消除.首先对每一道地震数据进行S变换时频滤...     

基于地震信号相似性的S变换域多次波压制技术

多次波压制是海洋地震数据处理的关键,如何保护一次反射波的同时高效准确地识别并压制多次波是地震资料处理的重点。笔者在共中心点(CMP)叠加压制多次波方法的基础上,基于CMP道集地震信号与叠加道地震信号的相似性特征在S变换域进行多次波压制。首先,利用多次波速度动校正并对CMP道集数据减去叠加道数据完成第一次多次波减除,此时,波场中残余的多次波以随机噪声的形式存在;然后,对减除多次波的地震波场应用一次波速度动校正,并以一次波速度叠加道为初始模型对CMP道集S变换谱进行相似性滤波完成第二次残余多次波去除。针对理论数据和实际数据进行了有效性测试,结果表明本文所提方法能够较好地压制多次波,提高反射波的成像精度。     

基于离散小波变换的地震资料自适应高频噪声压制

针对现有的小波变换阈值去噪方法无法适用于地震资料高频噪声压制的缺点,笔者分别对阈值函数和阈值选取方案进行了改进,提出了连续硬阈值函数与自适应阈值相结合的地震资料高频噪声压制方法.连续硬阈值函数兼具软、硬阈值函数的优点,可提高重构地震信号的保真度,减少人为噪声误差;自适应阈值方案可根据非平稳地震数据中的能量时变、空变分布特点,通过引入不同子带小波系数标准差、代数平均值以及几何平均值等统计参数,使阈值能够随不同子带的小波系数能量变化而自动调整,以适应地震资料高频噪声压制的要求.实际地震数据处理结果表明,笔者提出的方法在提高信噪比的同时,可保护陡倾角反射界面信号,提高噪声压制后地震数据的保真度.     

陆上地震数据多次波压制策略

在陆上地震勘探中,多次波反射与其他干扰波一样,干扰了有效波反射信号并降低了资料的信噪比。根据陆上地震数据中多次波与一次波所表现的不同特点,提出利用动校正叠加技术和频率-波数(f-k)滤波方法相结合的策略以压制地震数据中的多次波。使用一次波速度的动校正叠加技术可以衰减地震数据中的一部分多次波能量;根据叠加剖面确定包含剩余多次波的CMP范围,将f-k滤波方法应用于这些CMP道集上进一步压制多次波。模型试算和实际数据处理结果表明,所提出的多次波压制策略,不仅能有效地衰减多次波能量,而且在处理过程中可以减少对有效波信号的伤害。     

地震资料处理中的Radon变换及反Q滤波

Radon变换利用信号的横向相关性和信号根幅随炮检距变化的特征,提取有效反射信号同相轴,同时提取的零炮检距地震剖面,保留了地震记录的高频信息,达到了提高分辨率的目的。叠前反Q滤波是以FUTTERMAN衰减模型为理论基础,校正地震子波相位拉伸,补偿地震波频率和振幅的损失,达到提高地震资料分辨率和信噪比及改善同相轴连续性的目的。     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

Message from the Editor-in-Chief

正Dear Authors and Readers:First of all,on behalf of the new Editorial Board,I would like to express our sincere appreciation for your continuing support of our journal.This journal,founded in 1922,is the oldest geological journal in China.As the flagship journal of the Geological Society of China,it has become more and more influential in earth sciences in China and beyond.The journal is now indexed by SCI,CA and more than 20 other databases,with an impact     

Two and a Half Thousand Years of Navigation on the Dead Sea

正Today there is a single ship on the Dead Sea:a vessel that makes monthly research cruises.But in earlier periods many kinds of boats sailed the waves of the saltiest of all lakes.Stone and wooden anchors found on the newly     

Acta Geologica Sinica （English edition） Calls For Open-dated Submission of Paleontological Papers

正Acta Geologica Sinica(English Edition)is indexed by SCI,with the impact factors ranging from 1.5 to 2.15,and also indexed by CA,the Bibliography and Index of Geology(BIG),Biological Abstracts,and Geographical Abstracts and many others.Internationally,Acta Geologica Sinica(English Edition)has been cooperated with Willey-Blackwell     

Hydrogen and Oxygen Isotopes of Fluid Inclusion in Halite,Northern Shaanxi Salt Basin China

正The Ordovician was an important transitional period for global climate and organic evolution,the global was in the flood and glacial,Onganism was extinction(Zhan,2007;Trotter et al.,2008;Axel et al.,2010).Under the influence     

2015–2020 Geological Survey Program of China Geological Survey Bureau

正On 1–5 September 2014,the China Geological Survey Bureau held a 2015–2020 Geology and Mineral Resources Investigation and Assessment Special Planning and Deployment Meeting to plan the next six years in order to invest nearly ten billion US dollars to implement 9 programs and 50 projects with the aim of developing geological survey work,and to play a leading role in ensuring sustained and stable development.1 The Land Energy and Mines Geological Survey Program     

Deep Drilling Campaign in the Western Qaidam Basin,NE Tibetan Plateau and their Revealed Global Temperature Forcing of Salt Formation in the Late Miocene-Quaternary

正The Qaidam Basin in the NE Tibetan Plateau has contributed the largest amount of potash in China.However,how the potash was formed has long been a subject of debate.Here we carried out a deep drilling     

The Drifting History of the China Main Blocks during Specific Periods and their Tectonic Constraints on Marine Potash Formation

正1 Introduction Most of the world well know potash mines are deposited in marine environment.Regarding the serious potash shortage,no significant progress has been made in marine potash in China,while the terrestrial potash     

Discussion on the development of salt chemical industry chain

正China Pingmei Shenma Group is a large enterprise based on energy and chemical,with an annual output of 70million tons of coal,16 million tons of coke,680,000 tons of caustic soda,450,000 tons of PVC resin,50,000 tons of     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)