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31.
对Vondrak滤波的准则函数进行了探讨,提出了一种新的评价标准,即用滤波值的均方根误差与平滑度的线性组合的平方根δ作为平滑因子质量好坏的评价标准。模拟算例证实了此评价标准的可行性。 相似文献
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Analysis of time‐lapse travel‐time and amplitude changes to assess reservoir compartmentalization 
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下载免费PDF全文 Fluid depletion within a compacting reservoir can lead to significant stress and strain changes and potentially severe geomechanical issues, both inside and outside the reservoir. We extend previous research of time‐lapse seismic interpretation by incorporating synthetic near‐offset and full‐offset common‐midpoint reflection data using anisotropic ray tracing to investigate uncertainties in time‐lapse seismic observations. The time‐lapse seismic simulations use dynamic elasticity models built from hydro‐geomechanical simulation output and a stress‐dependent rock physics model. The reservoir model is a conceptual two‐fault graben reservoir, where we allow the fault fluid‐flow transmissibility to vary from high to low to simulate non‐compartmentalized and compartmentalized reservoirs, respectively. The results indicate time‐lapse seismic amplitude changes and travel‐time shifts can be used to qualitatively identify reservoir compartmentalization. Due to the high repeatability and good quality of the time‐lapse synthetic dataset, the estimated travel‐time shifts and amplitude changes for near‐offset data match the true model subsurface changes with minimal errors. A 1D velocity–strain relation was used to estimate the vertical velocity change for the reservoir bottom interface by applying zero‐offset time shifts from both the near‐offset and full‐offset measurements. For near‐offset data, the estimated P‐wave velocity changes were within 10% of the true value. However, for full‐offset data, time‐lapse attributes are quantitatively reliable using standard time‐lapse seismic methods when an updated velocity model is used rather than the baseline model. 相似文献
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提出了确定断层带结构的一种方法,它利用基于断层带围陷波波形相关的网格搜索法,以定量地确定断层带参数.该方法通过建立一系列由断层带的相关参数构建的断层带结构模型,利用有限差分方法数值模拟每组参数对应的断层带模型所产生的围陷波,并与实际观测围陷波波形进行相关分析,计算由以断层参数为多维网格坐标的相关系数变化趋势,网格搜索其峰值,最终获得最佳的一组参数,并确定断层带的结构.本文对昆仑山断裂带人工激发的围陷波进行分析,利用该方法确定了断裂带宽度和Q值参数. 相似文献
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Airborne Lidar bathymetry (ALB) is an effective and a rapidly advancing technology for mapping and characterizing shallow coastal water zones as well as inland fresh-water basins such as rivers and lakes. The ability of light beams to detect and traverse shallow water columns has provided valuable information about unmapped and often poorly understood coastal and inland water bodies of the world.Estimating ALB survey results at varying water clarity and depth conditions is essential for realizing project expectations and preparing budgets accordingly. In remote locations of the world where in situ water clarity measurements are not feasible or possible, using multiband satellite imagery can be an effective tool for estimating and addressing such considerations.For this purpose, we studied and classified reflected electromagnetic energy from selected water bodies acquired by RapidEye sensor and then correlated findings with ALB survey results. This study was focused not on accurately measuring depth from optical bathymetry but rather on using multiband satellite imagery to quickly predict ALB survey results and identify potentially turbid water bodies with limited depth penetration. For this study, we constructed an in-house algorithm to confirm ALB survey findings using bathymetric waveform information.The study findings are expected to contribute to the ongoing understanding of forecasting ALB survey expectations in unknown and varying water conditions, especially in remote and inaccessible parts of the world. 相似文献
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较大地震破裂尺度的一种简单估算 总被引：4，自引：0，他引：4
通过对各向同性均匀介质中两个点源的波形传播的几何性质的分析，提出对较大地震的破裂尺度的估计，可以采用多个子事件的模拟，根据接收台站得到的子事件的视时间差的分布特征，判断震源的实际破裂方向和破裂尺度，甚至仅仅根据宽频带Ｐ波（组）的波形宽度就可进行近似的估算。 相似文献
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The advent of high-resolution digital seismic recording and advances in computer technology enable the combination of traditional regional seismic network observations with direct seismogram modeling to improve estimates of small earthquake faulting geometry, depth, and size. We illustrate a combined modeling approach using observations from three earthquakes that occurred within the environs of the New Madrid Seismic Zone: two Missouri earthquakes from September 26, 1990 and May 4, 1991; and the southern Illinois earthquake of February 5, 1994. We also re-examine the faulting geometry for two events from the 1960s that are inconsistent with the current estimate of the regional stress field. Based on direct modeling of the long-period seismograms associated with these events, we revise earlier estimates of the earthquake parameters for the March 3, 1963 and July 21, 1967 Missouri earthquakes. Comparing the new and revised results with existing earthquake mechanisms in the region, we find that tension-axes are generally aligned in a N-S to NW-SE direction, while the compression-axes trend in a NE to E direction. An interesting exception to this pattern are the March 3, 1963 and two nearby earthquakes that lie within a well-defined 30-km long left step in seismicity near New Madrid. 相似文献
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由于小波变换特殊的性质决定了其在GPS监测数据中的应用，它能够提高GPS的定位精度和速度，并且在周跳检测、波形分解、消除噪声、数据压缩等方面大有可为。 相似文献