Efficient and Stable Absorbing Boundary Condition In Finite-Difference Calculations
    1.
    发明申请
    Efficient and Stable Absorbing Boundary Condition In Finite-Difference Calculations 审中-公开
    有限差分计算中有效和稳定的吸收边界条件

    公开(公告)号:US20160238723A1

    公开(公告)日:2016-08-18

    申请号:US14968961

    申请日:2015-12-15

    IPC分类号: G01V1/28 G06F17/10

    摘要: Method for generating an effective, efficient, and stable absorbing boundary condition in finite-difference calculations, such as model-simulation of predicted seismic data. The top surface and optionally the bottom surface of the computational domain or grid are treated with one or more layers of PML (51), preferably 1D PML, assuming an orthorhombic medium in the PML implementation (52). The side surfaces are handled with one or more ABC layers (53). Further advantages may be realized by tapering earth model symmetry axis on the top and bottom of the model toward the vertical (54). The invention provides a beneficial compromise between reducing artifacts in the image or physical property model and computational efficiency and stability.

    摘要翻译: 在有限差分计算中生成有效,有效和稳定的吸收边界条件的方法,如预测地震数据的模拟仿真。 假设PML实现中的正交介质(52),用一个或多个PML(51)层,优选1D PML层处理计算域或栅格的顶表面和任选地底表面。 侧表面用一个或多个ABC层(53)处理。 可以通过将模型的顶部和底部上的地球模型对称轴朝向垂直方向(54)来实现进一步的优点。 本发明在减少图像中的伪影或物理性质模型以及计算效率和稳定性方面提供了有益的折中。

    Method for Temporal Dispersion Correction for Seismic Simulation, RTM and FWI
    3.
    发明申请
    Method for Temporal Dispersion Correction for Seismic Simulation, RTM and FWI 审中-公开
    用于地震模拟,RTM和FWI的时间色散校正方法

    公开(公告)号:US20150355356A1

    公开(公告)日:2015-12-10

    申请号:US14670085

    申请日:2015-03-26

    IPC分类号: G01V1/32 G01V1/48 G01V1/36

    摘要: Method for correcting seismic simulations, RTM, and FWI for temporal dispersion due to temporal finite difference methods in which time derivatives are approximated to a specified order of approximation. Computer-simulated seismic data (51) are transformed from time domain to frequency domain (52), and then resampled using a mapping relationship that maps, in the frequency domain, to a frequency at which the time derivative exhibits no temporal dispersion (53), or to a frequency at which the time derivative exhibits a specified different order of temporal dispersion. Alternatively, measured seismic data from a field survey (61) may have temporal dispersion of a given order introduced, by a similar technique, to match the order of approximation used to generate simulated data which are to be compared to the measured data.

    摘要翻译: 用于由时间有限差分法校正地震模拟,RTM和FWI用于时间色散的方法,其中时间导数近似为指定的近似次数。 计算机模拟地震数据(51)从时域(52)变换到频域(52),然后使用在频域中映射到时间导数不显示时间色散的频率的映射关系重新采样(53) 或时间导数呈现指定的不同时间色散顺序的频率。 或者,来自现场勘测(61)的测量的地震数据可以通过类似的技术具有引入的给定次序的时间色散,以与用于生成将与测量数据进行比较的模拟数据的近似的顺序相匹配。

    Poynting Vector Minimal Reflection Boundary Conditions
    4.
    发明申请
    Poynting Vector Minimal Reflection Boundary Conditions 审中-公开
    坡印矢量最小反射边界条件

    公开(公告)号:US20160223697A1

    公开(公告)日:2016-08-04

    申请号:US14887621

    申请日:2015-10-20

    IPC分类号: G01V1/28 G06F17/16

    摘要: A method for exploring for hydrocarbons, including: simulating a seismic waveform, using a computer, wherein computations are performed on a computational grid representing a subsurface region, said computational grid using perfectly matched layer (PML) boundary conditions that use an energy dissipation operator to minimize non-physical wave reflections at grid boundaries; wherein, in the simulation, the PML boundary conditions are defined to reduce computational instabilities at a boundary by steps including, representing direction of energy propagation by a Poynting vector, and dissipating energy, with the dissipation operator, in a direction of energy propagation instead of in a phase velocity direction; and using the simulated waveform in performing full waveform inversion or reverse time migration of seismic data, and using a physical property model from the inversion or a subsurface image from the migration to explore for hydrocarbons.

    摘要翻译: 一种用于探索碳氢化合物的方法,包括:使用计算机模拟地震波形,其中在表示地下区域的计算网格上执行计算,所述计算网格使用完全匹配层(PML)边界条件,其使用能量耗散算子 最小化网格边界处的非物理波反射; 其中,在模拟中,定义了PML边界条件以减少边界处的计算不稳定性,所述步骤包括表示坡坡廷矢量的能量传播方向,以及耗散算子在能量传播方向上耗散能量,而不是 在相速度方向上; 并使用模拟波形进行地震数据的全波形反演或反向时间偏移,并使用来自反演的物理性质模型或来自迁移的地下图像来探索碳氢化合物。