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131.
Scattered ground roll is a type of noise observed in land seismic data that can be particularly difficult to suppress. Typically, this type of noise cannot be removed using conventional velocity‐based filters. In this paper, we discuss a model‐driven form of seismic interferometry that allows suppression of scattered ground‐roll noise in land seismic data. The conventional cross‐correlate and stack interferometry approach results in scattered noise estimates between two receiver locations (i.e. as if one of the receivers had been replaced by a source). For noise suppression, this requires that each source we wish to attenuate the noise from is co‐located with a receiver. The model‐driven form differs, as the use of a simple model in place of one of the inputs for interferometry allows the scattered noise estimate to be made between a source and a receiver. This allows the method to be more flexible, as co‐location of sources and receivers is not required, and the method can be applied to data sets with a variety of different acquisition geometries. A simple plane‐wave model is used, allowing the method to remain relatively data driven, with weighting factors for the plane waves determined using a least‐squares solution. Using a number of both synthetic and real two‐dimensional (2D) and three‐dimensional (3D) land seismic data sets, we show that this model‐driven approach provides effective results, allowing suppression of scattered ground‐roll noise without having an adverse effect on the underlying signal. 相似文献
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伪谱和高阶有限差分混合方法, 在垂直方向采用交错网格有限差分算子, 利用其并行程度高的特点, 在水平方向采用伪谱算子, 保留其高精度的优势, 是计算地震波场的有效方法. 图形处理器(graphic processing unit, 简写为GPU) 由于其高度并行性, 在计算此类问题中有显著的优势. 由英伟达(NVIDIA)公司推出的统一计算设备架构(compute unified device architecture, 简写为CUDA)平台极大地简化了GPU编程的难度. 为提高计算效率, 本文实现了基于CUDA 平台的混合方法二维地震波场模拟. 然后基于二维均匀介质模型将CPU与GPU版本的运行时间进行对比. 实际测试结果表明, 基于CUDA 的并行模拟方法在保证计算精度的同时显著地提高了计算速度, 为开展大规模非均匀地球介质地震波传播数值模拟提供了一种可选的方法. 相似文献
134.
During the time taken for seismic data to be acquired, reservoir pressure may fluctuate as a consequence of field production and operational procedures and fluid fronts may move significantly. These variations prevent accurate quantitative measurement of the reservoir change using 4D seismic data. Modelling studies on the Norne field simulation model using acquisition data from ocean-bottom seismometer and towed streamer systems indicate that the pre-stack intra-survey reservoir fluctuations are important and cannot be neglected. Similarly, the time-lapse seismic image in the post-stack domain does not represent a difference between two states of the reservoir at a unique base and monitor time, but is a mixed version of reality that depends on the sequence and timing of seismic shooting. The outcome is a lack of accuracy in the measurement of reservoir changes using the resulting processed and stacked 4D seismic data. Even for perfect spatial repeatability between surveys, a spatially variant noise floor is still anticipated to remain. For our particular North Sea acquisition data, we find that towed streamer data are more affected than the ocean-bottom seismometer data. We think that this may be typical for towed streamers due to their restricted aperture compared to ocean-bottom seismometer acquisitions, even for a favourable time sequence of shooting and spatial repeatability. Importantly, the pressure signals on the near and far offset stacks commonly used in quantitative 4D seismic inversion are found to be inconsistent due to the acquisition timestamp. Saturation changes at the boundaries of fluid fronts appear to show a similar inconsistency across sub-stacks. We recommend that 4D data are shot in a consistent manner to optimize aerial time coverage, and that additionally, the timestamp of the acquisition should be used to optimize pre-stack quantitative reservoir analysis. 相似文献
135.
Mustafa Al-Marzooq Mamadou S. Diallo Vincent Etienne Thierry Tonellot SanLinn I. Kaka 《Geophysical Prospecting》2019,67(7):1825-1837
The Rub Al Khali region in Saudi Arabia is characterized by the presence of sand dunes separated by salt flats, also called Sabkhas. In general, the elevation of dunes in this region varies between 90 and 250 m above sea level. The presence of these sand dunes, along with the rapidly changing surface topography poses challenges for seismic data acquisition and processing. The high contrast in acoustic impedance between the dune base and the underlying formation often results in amplification of seismic waves that are recorded at stations located on the surface of sand dunes. Attempts to address the issue using conventional surface-consistent amplitude scaling methods without reducing these amplification effects generally fail, thus compromising the suitability of the processed data for amplitude versus offset analysis. In this study, we propose a new reference site technique to reduce the effects of sand dune amplification, enabling the production of data sets that are suitable for amplitude versus offset processing. The proposed technique uses a deterministic approach to derive surface-consistent, frequency-dependent de-amplification functions for shots and stations located on the dunes only. Two-dimensional synthetic and field data examples show that the technique significantly reduces the effects of sand dune amplification. 相似文献
136.
海底地震仪(Ocean Bottom Seismometer, OBS)数据处理至关重要,是获取深部地壳结构的基础与前提.2006年实施OBS2006-2测线时,有2台OBS(OBS03,OBS06)数据出现异常,无法使用.由于海上航次花费巨大,采集到的数据弥足珍贵.本文采用数据格式检查、邻近台站对比分析、重采样等方法,成功地对这2台OBS数据进行了解编处理,得到了这两个台站的综合地震记录剖面;利用上述方法对2011年实施的OBS973-3测线中的异常台站OBS03进行了分析处理,同样得到了OBS03台站的综合地震剖面;通过查看两次海上实验班报发现,OBS2006-2测线之OBS06与OBS973-3测线之OBS03内部Sedis编号相同,为同一台记录仪器,再一次验证上述处理方法正确可行;然后对OBS2006-2测线2个台站进行震相识别与走时拾取后,利用前人纵波速度模型开展了射线追踪与走时模拟.此次对异常OBS数据的重新处理工作,不仅为OBS探测提供了宝贵的数据处理经验,而且将提高OBS2006-2测线地壳结构的可靠性和约束性,具有重要的研究意义. 相似文献
137.
多金属成矿区深地震反射剖面数据处理技术实验研究——以庐枞矿集区为例 总被引:1,自引:1,他引:1
针对庐枞多金属矿集区地震资料特点及浅、深多重探测目标,对深地震反射数据进行了处理技术实验研究。在区域长剖面上,为了获得矿集区地壳与上地幔结构的精细图像,解释成矿深部过程,开展了循序渐进的常规处理技术实验和精细处理技术实验。在矿区剖面,为了获得了浅层精细结构,针对变观测系统接收等特点,进一步开展了特殊处理实验。经过区域剖面与矿区剖面的多重处理实验,集成了一套矿集区深地震反射剖面数据处理方法与处理技术流程,为我国进一步的深部探测积累了技术与经验。 相似文献
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140.
冰川堆积物的粒度组成在很大程度上控制了其物理力学性质,但常规试验无法得到连续的冰川堆积物的粒度组成数据.应用数字图像处理技术和室内试验相结合的分析方法,首先借助图像处理技术,对冰川堆积物剖面的砾石形态进行分析.获取粗粒部分(>2cm)的粒度组成,然后采用室内颗分试验获得细粒(<2cm)部分的粒度组成,将2类粒度数据进行叠合即可获取连续的冰川堆积物的粒度组成.结果表明:研究区冰ill堆积物的粒度组成极不均匀且颗粒分析曲线呈现多峰性,具有良好的级配和工程性质;冰川堆积物的粒度组成、砾石形态和排列特征都有很好的分形特征. 相似文献