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欧美应用地球物理现状——多波地震勘探 总被引:2,自引:0,他引:2
随着多道遥测地震仪和三分量数字检波器的问世及数字处理和资料解释技术的进步,众多欧美大学、研究所及油气公司的地球物理学者针对多波地震勘探理论、资料处理模块、纵波对比试验等开展了大量的研究工作。目前深层横波震源技术尚不成熟,大量的多波技术研究仍然是针对转换波。为保证纵波资料质量,一些项目将传统检波器获得的纵波资料与三分量获得的纵波资料进行对比,即用三分量数字检波器采集的同时,仍用传统纵波检波器进行采集。此外,与三维三分量地震勘探相配套的三维多波VSP技术等也处于研究之中。 相似文献
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山地二维三分量地震资料采集 总被引:3,自引:3,他引:0
新研制出的一种三分量检波器,尾锥不动,能方便地调节其方位角和水平角,可保证同一测线上的检波器各分量的极性和相位一致,检波器与地面耦合良好;三个分量之间的隔离度大于20dB,保证了道间无串音干扰。三个检波器串联组合,有利于地震信号接收。通过数值模拟拟定出地震测线布设方位和观测系统,在采集试验中开展波场调查、偏移距试验、不同覆盖次数对比,以确定出合理的观测系统和采集参数,在四川山地获得了高质量的三分量地震资料,形成了一套实用的陆上三分量地震资料采集技术。 相似文献
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已有的三分量检波器在尾锥与地表紧耦合条件下 ,无法调节方位角及倾角。首次利用袖珍经纬仪指示方位角和水平程度 ,再由万向装置调节 ,使所有新型正交型三分量检波器的方向 ,在一条测线的各物理点上一致 ,保证方位角误差小于 2°,且每个检波器的xy面处于水平面 ,即z分量处于铅直方向 ,倾角误差小于 1.5°。用新型正交型的三分量检波器和已有的三分量检波器进行现场试验。从试验结果看 ,用新型三分量检波器采集到的三分量资料的信噪比要比用原有的三分量检波器采集三分量资料高。 相似文献
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主要论述了两种三个分量之间不同角度的三分量检波器的性能对比试验。从该试验中,可以看出三分量检波器之间成90°角比成54°角的性能要好,用该检波器可以取得良好的三分量资料。 相似文献
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新-煤矿施工-投料孔,因钻孔偏斜,未打到大巷中,为测定其终孔位置,采用了地震直达波方法,即将地面设计的输料钻孔座标投影到-253m的大巷中,在其周围有规则的布设24道检波器,将少量炸药下到投料孔底部进行激发,根据初至波时间确定投料孔的终孔位置。 相似文献
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针对目前国内外54°三分量检波器串扰测试方法存在的许多问题,着重介绍了三分量检波器测试方法。该方法在不降低精度的前提下,可大大简化电路,节省费用。 相似文献
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孔中物探方法是近几年行业研究的热点,考虑到金属矿上应用较成熟的地-孔瞬变电磁法具有径向探测距离远,数据信号不易受地面电磁干扰影响等特点,将其应用到煤矿积水采空区探查领域。采用三维时域有限差分算法对钻孔不同方位的积水采空区模型的总场响应、异常响应进行了数值模拟,总场三分量对积水采空区反映明显,异常场三分量形态组合能判别异常体的方位。采用等效涡流原理,研究了利用异常场三分量来反演异常体的位置、倾角和规模等参数的空间定位算法。通过不同方位的理论模型测试,不同时刻的反演等效电流环大小、位置的组合能反应含水采空区的空间位置及规模。最后在陕北某矿针对已知含水采空区开展地-孔瞬变电磁法探测试验,采集的三分量信号光滑可靠,且异常反应明显,并对不同时刻的异常场三分量数据进行反演处理,反演结果与实际采空区位置和规模基本一致,证明该方法可作为煤矿钻孔中探查积水采空区的有效手段。 相似文献
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《Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy》2000,25(2):119-126
Measurements of P-wave velocity at room temperature and confining pressures up to 500 MPa were carried out on three eclogite mylonites collected from a shear zone in the Monviso area (Western Alps). P-wave velocities at a pressure of 400 MPa range from 7.7 km/s to 7.9 km/s, yielding to a maximum anisotropy of 6%. From the CPO of omphacite we estimated a maximum contribution of omphacite to the P-wave anisotropy of only 1.3%. These results suggest that primarily the compositional layering and secondary the fabric of minor constituent minerals significantly contribute to the seismic anisotropy. Because of the anisotropy, the seismic reflectivity of subduction zones may vary with the direction of observation. 相似文献
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Lepore Simone Polkowski Marcin Grad Marek 《International Journal of Earth Sciences》2018,107(6):2043-2062
International Journal of Earth Sciences - The P-wave velocities (Vp) within the East European Craton in Poland are well known through several seismic experiments which permitted to build a... 相似文献
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Butsenko V. V. Poselov V. A. Zholondz S. M. Smirnov O. E. 《Doklady Earth Sciences》2019,488(2):1182-1185
Doklady Earth Sciences - The purpose of this work was to study the seismic attributes of the Podvodnikov Basin basement. It was found that these attributes, first of all, P-wave velocities of... 相似文献
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波速测试技术是地震勘探方法之一,也是一种简便、快速、准确的原位测试技术。它通过获取的地震波在经过不同深度的岩、土层的直达波旅行时,求得纵波、剪切波波速,进而通过弹性波理论,计算出岩、土层动弹性力学参数,同时也可以根据剪切波的波速,来划分场地土类型和建筑场地类别,以及计算卓越周期,这些参数可以为场地抗震设计及地震安全性评价提供依据。这里简述了波速测试技术的工作原理和野外实测技术,以及数据处理和资料解释全过程,并且结合某一建筑场地的实例,说明了波速测试技术在场地抗震评价中的应用及其效果。 相似文献
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Crustal structure of the Eastern Alps along the TRANSALP profile from wide-angle seismic tomography 总被引:1,自引:1,他引:1
The objective of the TRANSALP project is an investigation of the Eastern Alps with regard to their deep structure and dynamic evolution. The core of the project is a 340-km-long seismic profile at 12°E between Munich and Venice. This paper deals with the P-wave velocity distribution as derived from active source travel time tomography. Our database consists of Vibroseis and explosion seismic travel times recorded at up to 100 seismological stations distributed in a 30-km-wide corridor along the profile. In order to derive a velocity and reflector model, we simultaneously inverted refractions and reflections using a derivative of a damped least squares approach for local earthquake tomography. 8000 travel time picks from dense Vibroseis recordings provide the basis for high resolution in the upper crust. Explosion seismic wide-angle reflection travel times constrain both deeper crustal velocities and structure of the crust–mantle boundary with low resolution. In the resulting model, the Adriatic crust shows significantly higher P-wave velocities than the European crust. The European Moho is dipping south at an angle of 7°. The Adriatic Moho dips north with a gentle inclination at shallower depths. This geometry suggests S-directed subduction. Azimuthal variations of the first-break velocities as well as observations of shear wave splitting reveal strong anisotropy in the Tauern Window. We explain this finding by foliations and laminations generated by lateral extrusion. Based on the P-wave model we also localized almost 100 local earthquakes recorded during the 2-month acquisition campaign in 1999. Seismicity patterns in the North seem related to the Inn valley shear zone, and to thrusting of Austroalpine units over European basement. The alignment of deep seismicity in the Trento-Vicenza region with the top of the Adriatic lower crust corroborates the suggestion of a deep thrust fault in the Southern Alps. 相似文献