共查询到18条相似文献，搜索用时 484 毫秒
1.
在叠前共深度点道集内各地震道的动、静校正误差很小的情况下,地震资料时间域水平叠加方法有较好的叠加结果.但是,如果动、静校正的误差较大时,叠加效果将受到影响,即叠后振幅和分辨率都会降低.因此,提出一种频率域叠加方法.该方法既具有常规水平叠加方法能提高信噪比的优点,又能将共深度点道集内的走时时差消除,达到同相叠加的目的.几个比较叠加方法效果的有噪CDP道集叠加的例子证明了该方法的效果. 相似文献
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3.
扼要介绍了线性定解问题的叠加原理。进而讨论了叠加原理在地下水流模型中的应用问题——地下水流模型的分解与叠加。在新增激发条件下,为便于问题的分析及模型的求解,可将模型分解为初始流场模型与附加水头场模型。模型分解与叠加不仅可简化复杂模型的求解问题,更有助于对水文地质过程的理解。利用附加水头场反求参数以及解决当初始水位非水平、非稳定时,Dupuit公式、Theim公式和Theis公式的应用问题,将显得十分便利。 相似文献
4.
对一种能增强工程地震勘探数据质量的新叠加技术——零偏移距共反射面叠加进行了研究。目前模拟零偏移距剖面常规方法存在需要精确宏速度模型及不能对地下反射界面产生最佳照明的问题,而零偏移距共反射面叠加具有完全数据驱动、与宏速度模型无关、能够产生对地下反射界面最佳照明及提高模拟零偏移距剖面成像质量的优势。针对零偏移距共反射面叠加还未在国内工程地震勘探中进行广泛应用的现状,详细介绍了零偏移距共反射面叠加基本原理及其实现过程,并使用一套人工合成断层模型数据及来自某高速公路段附近一条二维测线的实际工程地震勘探数据进行了测试计算。理论模型试算结果及在工程地震勘探实际资料处理中的应用表明零偏移距共反射面叠加可提高地震数据信噪比,增强地震反射同相轴连续性,改善模拟零偏移距剖面质量,是一种非常有发展前景的工程地震成像方法。 相似文献
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叠加原理在水文地质计算中的应用相当普遍,但一般局限于地下水流模型的解析解,本文扼要介绍了线性定解问题的叠加原理,在此基础上提出了线性离散模型的叠加原理,进而讨论了线性离散模型的叠加原理在地下水流数值模型中的应用一一地下水流数值模型的分解与叠加.模型分解与叠加既可用于解析分析也可用于数值计算;同时不仅可以简化复杂模型的求解问题,更有助于理解地下水变化过程. 相似文献
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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。 相似文献
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时间域航空电磁数据加权横向约束反演 总被引：3，自引：0，他引：3
传统的单点一维反演技术处理时间域航空电磁数据得到的电阻率和层厚度容易呈现横向不连续性,导致层界面不光滑。即使相邻测点的反演结果也会出现突变现象,与实际地质情况不符,给解释工作带来困难。笔者针对时间域航空电磁数据空间采样密集、在沉积岩地区工作时地下电性结构横向连续性较好的特点,研究了时间域航空电磁数据参数加权横向约束反演方法。反演时同时考虑数据拟合、相邻测点电阻率和层厚度横向约束以及深度横向约束,利用参数加权来调整对各层模型参数和深度横向光滑度的约束强度。通过对理论和实测数据反演并与传统的单点一维反演结果进行对比,验证了拟二维横向加权约束反演是处理时间域航空电磁数据的有效方法。横向约束反演结果电阻率和层厚度横向光滑连续,层界面清晰。引入参数加权实现对不同参数横向光滑度和连续性的制约,可进一步提高反演解的稳定性。加权因子对反演结果有较大影响,在实际应用中,应该综合考虑地质资料选择合适的加权因子。 相似文献
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《物探化探计算技术》2020,(1)
目前深度域地震资料日益增多,为充分利用这些资料精确地描述地下地质结构,实现高精度构造解释、储层预层及流体识别,开展深度域地震数据的分析成为目前研究的重点方向之一。在前人研究成果的基础上,分析和讨论了基于不同均匀介质模型情况下的深度域子波和深度域合成地震记录,给出了基于褶积理论的深度域子波和深度域合成记录表达式。模型试算和对Marmous数据运算表明,时间域地震数据和深度域地震数据存在一定的差异,前者并不能完全准确反映地下地质情况,而后者更加接近真实地下构造;深度域地震数据更利于含油气储层构造和岩性解释,提高复杂地质构造区的勘探精度。 相似文献
9.
本文介绍了叠加原理在地下水资源规划中的应用。方法实用新颖,模型的分解使复杂问题简单化。该方法多应用于解非齐次边界的多井含水层系统 相似文献
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《物探与化探》2015,(3)
叠加是地震数据处理的核心环节,可以有效地压制噪声提高信噪比。在VSP地震勘探中,常规的叠加方法在复杂构造中成像精度受到极大的限制。文中采用高斯射线束方法对复杂构造进行正演模拟,将得到的波场特征与实际资料波场特征进行对比,调整参数获得合适的速度场;在叠加过程中采用逆高斯的思想,对实际地震资料共炮集数据进行反射波场归位,得到共反射点道集数据,选择合适的面元尺寸进行叠加获得复杂构造的叠加波场特征。通过大量模型测试,VSP高斯束叠加方法可以有效地反演地下结构特征。应用该方法对M地区进行成像研究,结果表明该方法能够准确反演地下结构特征,为数据处理与解释提供依据。 相似文献
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The increasing impacts of natural disasters on disadvantaged rural areas, especially in developing countries, have led to concerns regarding post-disaster rural settlement reconstruction. Various approaches, including resettlement and in-situ reconstruction, have been adopted, both of which disregard changing the pattern of dispersed settlement in villages. Against a pattern of dispersed settlement, developing a concentrated rural settlement (CRS) within a village is argued to enable the resilience of rural villages and provide a basis for sustainable development after a disaster. Nevertheless, this has received little attention when determining a plan of actions for post-disaster reconstruction. No specific guidelines can be referenced when developing CRS in post-disaster reconstruction due to the lack of a generic decision model. Therefore, this study examines the process of developing CRS in post-disaster reconstruction by mapping four cases selected in Dujiangyan, China, after the 5.12 Sichuan Earthquake in 2008. The examination leads to establishing a generic decision model for developing CRS in post-disaster reconstruction, which incorporates all the proficiencies embodied in the existing practices. This model provides an alternative tool for planning CRS in post-disaster reconstruction. It can also serve as a vehicle for identifying both effective practices and weak areas by comparing varying cases. 相似文献
12.
一种基于Mapinfo的叠加分析方法 总被引：2，自引：0，他引：2
作者在本文中简单介绍了GIS中的叠加分析及其与成矿预测的关系，提出了一种基于Mapinfo的叠加分析方法，先生成新的网格图层，在网格图层的基础上进行图层的叠加分析，进而到成矿预测的目的。同时，该方法也适用于其它应用领域，这种叠加分析的思路也可以用于其它的地理信息系统中。 相似文献
13.
泊松比因其物理意义明确,区分岩性和流体的效果明显,作为最重要的岩石物理参数之一被广泛地应用于储层预测研究中。在实际应用中,泊松比参数的获取主要通过先反演得到纵波、横波速度之后的转化计算,误差累积明显。AVO近似方程是振幅类反演技术的理论核心,不同表达形式的AVO近似方程所突出的物理意义也不同。基于叠前AVA多参数同步反演理论,提出一种全新的AVO近似方程,利用该AVO近似方程推导出新的递推关系式同步反演出泊松比、纵波速度、密度等弹性参数。模型与实际应用分析均表明,同步反演得到的泊松比参数有效地减少了因常规间接计算带来的累积误差,提高了储层预测精度。 相似文献
14.
Much discussion has centered around which 210Pb dating method should be used, the constant initial concentration (CIC) model or the constant rate of supply (CRS) model.
In this study, the activity data from 22 lacustrine sediment cores from the Canadian prairies were used to compare the determination
of sediment accumulation using the two models. Other relative and absolute dating techniques have been used to calibrate the
methodology. For half of the core sites examined, the mass sedimentation rate was constant, and thus both the CIC and CRS
models were found to be valid. For the other half, variability was observed in the CRS mass accumulation rate trend. The validity
of the CIC model for these cores was dependent on the degree of variability of the mass sedimentation rate. Where the variability
is moderate to high, the CRS model may be more satisfactory. Caution should be exercised when using chronological data determined
with the CRS model, however, as the accuracy of chronology in the lower reaches of a profile is questionable.
Received: 11 May 1995 · Accepted: 16 August 1995 相似文献
15.
Edward D. Burton Leigh A. SullivanRichard T. Bush Scott G. JohnstonAnnabelle F. Keene 《Applied Geochemistry》2008
A new chromium-reducible sulfur (CRS) method suitable for the quantification of reduced inorganic S (RIS) in acid-sulfate soils is presented. The new method utilises the reduction of RIS by an acidic Cr(II) solution within a sealed reaction chamber and diffusion of the produced H2S(g) into an alkaline Zn solution. It offers rapid sample processing times, without the need for large volumes of high-purity N2(g) or for specialized, expensive glassware. Examination of pyrite-talc mixtures containing up to 11.8% pyrite, revealed that the method achieves 95–98% recovery of RIS. A comparison between CRS measured by the new diffusion-based method and that measured by a standard purge-and-trap method for 25 pyritic soil samples shows a very strong (r2 = 0.996) linear relationship with a slope of 0.995. The ability of the new diffusion-based CRS method to achieve accurate and precise quantification of RIS in acid-sulfate soils is demonstrated. 相似文献
16.
Qiao Xiufu Gao Linzhi 《中国地质大学学报(英文版)》1996,(1)
TheNcoproterosoiciswelldevelopedinHUnjiangarea,JinnProvince,andarecomposedoftheMadaling,Baffongh,DiaoyUtaiformationsoftheQingbaikouSyStemandtheNanfen,Qiaotou,Waulong,BadaojiangandQinggoUZifonnationsoftheSilvanSyStem.In1992,aresearchofsequencestratigraphywasdonethereforthefirsttime(GaoandQiao,1992).Since1993,duringthemappingofif50on,outcropsequenCestratigl'aphyhasfatherstudiedtherebrig.l).~ENCE~NDARYTheconceptofdepositionalsequencelicitedbyupperandloadunconfondtywaspointedoutbySlo… 相似文献
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Several experimental methods have been proposed for consolidation test such as: constant loading rate, constant gradient and
constant rate of strain (CRS). Unfortunately, there are no unique criteria for performing the CRS consolidation test. Also,
there are considerable differences among the standards proposed for the test. In the present paper, authors have tried to
find the reasons for differences among standards, by studying the basic assumptions made on the characteristics of the pore
water flow during consolidation process. In the course of study, CRS consolidation tests were carried out under different
strain rates on remolded samples. The results of the tests have indicated that the Darcy’s law is not valid throughout the
CRS test and therefore, any consolidation equation based on Darcy’s law would not provide accurate results. The results of
the current experiments also showed that with regard to the applied strain rates, there are three different flow regimes governing
the process named as: pre-linear (non-Darcy flow), linear (Darcy flow) and post-linear (non-Darcy flow). Experimental results
also showed that distinction between boundaries of linear and nonlinear flow is possible from the excess pore pressure developed
during the tests. 相似文献