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隐伏活断层地震勘探正演模拟方法 总被引：1，自引：1，他引：0
浅层高分辨率地震勘探是城市活断层探测手段中最有效、最可靠的方法之一,但是由于隐伏活断层勘探时存在着勘探深度浅、地层的属性差异小以及环境噪声大等因素,导致地震勘探数据信噪比低、反射信号弱等问题,严重影响地震数据的采集、处理和解释。采用一阶应力-速度方程的高阶交错网格有限差分方法, 结合完全匹配层(PML)的边界处理方法和通量校正(FCT)法消除频散的技术手段,对活断层模型地震勘探进行正演模拟,清晰直观地表现了断层处的细微差别,有助于地震勘探中对信号的分析与理解。结果表明,这些处理手段结合波动方程有限差分算法,能够有效实现薄层、弱反射的隐伏活断层模型的波场正演模拟,可有效识别隐伏活断层的断层倾角、断距、规模、跨越范围、断层深度以及断裂带影响范围,为分析这些参数对地震记录的影响提供有力帮助,同时结合实测地震数据的处理、解释,为防灾减灾提供具体有力的判据。 相似文献
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根据安徽淮南某煤矿的地质构造特点及煤层赋存形态,在三维地震测区中部选择了一条典型地质剖面,据此建立了陡倾角二维地震数学模型,并从波动方程出发确立了模型的三维地震观测系统。通过对正演模拟得到的炮集记录、叠加剖面、偏移剖面上的波场特征的分析,确定了适合勘探区地质条件的采集和处理方法。对该二维模型数据的处理结果表明,叠后偏移手段不适合陡倾角区煤层地震资料的处理,而叠前时间偏移可有效保证陡倾角勘探区块的地质目标成像。根据陡倾角目的层及逆掩断层区域开展地震勘探的难点问题,提出了适当调整观测系统、提高空间采样密度等措施。根据多年在淮南矿区开展采区三维地震勘探的工作经验,认为该区最佳观测系统为方位角特性好、共面元道集内炮检距分布均匀的八线八炮制束状规则观测系统。 相似文献
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可控震源地震勘探的数值模拟 总被引：5，自引：0，他引：5
用可控震源激发的线性扫频（Chirp）信号模拟了二维地震勘探,采用相关处理技术把反射Chirp地震信号转化为脉冲地震信号形成了相关地震剖面,把相关地震剖面与脉冲震源产生的合成地震记录剖面进行了对比。相关地震剖面同相轴波形的最大绝对值出现的位置反映了界面的真实位置信息。相关地震剖面比脉冲震源产生的合成地震记录剖面具有更高的分辨率。对震源扫频信号进行适当地锥化处理可以部分地压制相关地震剖面中反射地震信号的旁瓣。 相似文献
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在地震资料解释阶段,可根据解释结果进行正演模拟,以验证解释结果的可靠性,并通过模型正演方式了解地下波场的细微变化,提高解释精度。依据内蒙古鄂托克前旗沙章图矿区DF2逆断层的赋存形态,建立的地质模型,并围绕其逆断层的断点位置、埋深、地层速度等,对各种接收排列进行射线追踪实验。通过改变开动的道数、道距及偏移距,观察各种参数下射线追踪的分布情况及模拟时间剖面的面貌。正演结果表明利用射线模型追踪的模拟地震反射剖面与实际时间剖面完全吻合,其确定的逆断层断点位置及断面倾角合理。 相似文献
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基于一阶速度—应力弹性波波动方程,利用傅里叶变换将空间导数变换到频率域求解,对介质波场进行正演模拟。本文结合实际勘探中可能存在的地质问题,设计了多种地质模型,包括背斜模型、向斜模型、透镜体模型和断层--侵入体模型等,进行了伪谱法地震波场正演模拟、合成地震记录的实现,并分析了其波场动力学变化特征。结果表明,应用伪谱法对复杂模型的模拟有较高的精度和可靠性,可直接用于辅助地震野外工作设计、反演解释和资料解释等工作。 相似文献
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随着超深储层的油气勘探力度不断加大,针对复杂的表层结构和地下地质构造地区,常规地震勘探方法难以获取信噪比较高的有效反射信息,地震资料成像效果差,地震剖面难以清楚刻画工区的地质构造。因此,基于大型低频可控震源激发技术,根据野外采集要求,结合地质任务,选择采用高密度二维广角反射地震观测系统进行地震资料采集,通过广角地震波数值模拟和野外试验工作,优选出适合本工区的野外采集参数。研究结果表明,基于大型低频可控震源的超深储层广角反射采集技术,能够获得较强能量的远偏移距处的弱反射地震信号,特别是深层的低频信息,有效地提高了地震资料信噪比。相对于常规地震叠加剖面,广角反射地震叠加剖面品质得到明显改善,同相轴连续,构造部位清晰可见,地震成像效果良好。野外生产实践证明,广角反射地震勘探技术对超深层油气勘探具有重要的应用价值。 相似文献
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《物探与化探》2021,(4)
地震波正演模拟技术广泛应用于浅层勘探,此方法可以将地质模型和地震模型有机结合起来,验证和指导地震资料的采集、处理和解释。基于石油反射地震技术发展起来的深反射地震剖面探测技术,经过几十年的发展及应用,已经非常成熟,但到目前为止,地震波正演技术在深反射地震剖面探测中的应用却很少。本文利用跨越四川盆地深反射地震剖面来开展正演研究,通过对比拟合正演模拟数据和实际地震数据的层位到时,不断修正速度、层位等参数,建立最终深度域地质模型,为构造剖面提供较为准确的地壳厚度、莫霍面深度等地层信息。通过深度域地质模型,揭示出扬子板块西北缘新元古代古俯冲的角度约30°,俯冲的深度达到60 km。 相似文献
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在实际煤田地球物理勘探中,常规的地面地震勘探技术无法对煤层中的小断层、陷落柱、夹矸等微幅构造体进行精细的探测。相比于地面地震勘探,槽波地震勘探直接在煤层中激发,能量强,范围大,能够精确探测煤层中的微幅构造体。笔者等针对反射槽波地震数据的特征,给出了一种有效的反射槽波地震数据精细处理技术和流程,通过对频散分析以及槽波包络叠加等关键技术进行试验研究,提高反射槽波地震数据的成像精度,进而更准确地识别煤层中小断层等微幅构造。实际煤田反射槽波的应用试验表明,反射槽波勘探准确识别出煤层中的小断层构造,验证了反射槽波勘探技术的实用性以及本文反射槽波地震数据处理技术的有效性。 相似文献
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Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco. 相似文献
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Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
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The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species. 相似文献
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Muriel Rocher Stéphane Baize Stéphane Jaillet Edward Marc Cushing Yannick Lozac&#x;h Francis Lemeille 《Comptes Rendus Geoscience》2003,335(8):701-708
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003). 相似文献
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正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.) 相似文献
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正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology, 相似文献
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正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.) 相似文献
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正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se- 相似文献
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正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with 相似文献