Poynting Vector Minimal Reflection Boundary Conditions
    2.
    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。

    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。

    Full Waveform Inversion Using Perfectly Reflectionless Subgridding
    5.
    发明申请
    Full Waveform Inversion Using Perfectly Reflectionless Subgridding 审中-公开
    全波反射采用完全无反射的子网格

    公开(公告)号:US20140372043A1

    公开(公告)日:2014-12-18

    申请号:US14286107

    申请日:2014-05-23

    IPC分类号: G01V1/34

    CPC分类号: G01V1/303 G01V2210/679

    摘要: Method for reconstructing subsurface profiles for seismic velocity or other geophysical properties from recorded seismic data. In one embodiment, a starting model of seismic velocity is assumed (10). The computational domain is divided into two (or more) subdomains by horizontal planes based on an analysis of velocity model (30), and the allowed maximum grid size for each subdomain is determined (50). Auxiliary perfectly matched layers (PML's) are attached to each planar interface between subdomains (80), e.g. two PML's on each side of the interface between the coarse and fine subdomains. Simulated seismic data are computed using the SG-DO technique (100-230). The simulated seismic data are compared to the recorded seismic data, then the residual is calculated (240) and used to update the model (320). The method may be iterated until the model is suitably converged (260).

    摘要翻译: 从记录的地震数据重建地震速度或其他地球物理特性的地下剖面的方法。 在一个实施例中,假定地震速度的起始模型(10)。 基于速度模型(30)的分析,计算域由水平面划分为两个(或多个)子域,并确定每个子域的允许的最大网格大小(50)。 辅助完美匹配层(PML)附接到子域(80)之间的每个平面界面,例如。 两个PML在粗略和精细子域之间的界面的每一边。 使用SG-DO技术(100-230)计算模拟地震数据。 将模拟地震数据与记录的地震数据进行比较,然后计算残差(240)并用于更新模型(320)。 可以重复该方法,直到模型适当地收敛(260)。

    Efficient and Stable Absorbing Boundary Condition In Finite-Difference Calculations
    8.
    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。

    Iterative inversion of data from simultaneous geophysical sources
    10.
    发明授权
    Iterative inversion of data from simultaneous geophysical sources 有权
    同时地球物理资料数据的迭代反演

    公开(公告)号:US08428925B2

    公开(公告)日:2013-04-23

    申请号:US13345314

    申请日:2012-01-06

    IPC分类号: G06G7/48

    摘要: Method for reducing the time needed to perform geophysical inversion by using simultaneous encoded sources in the simulation steps of the inversion process. The geophysical survey data are prepared by encoding (3) a group of source gathers (1), using for each gather a different encoding signature selected from a set (2) of non-equivalent encoding signatures. Then, the encoded gathers are summed (4) by summing all traces corresponding to the same receiver from each gather, resulting in a simultaneous encoded gather. (Alternatively, the geophysical data are acquired from simultaneously encoded sources.) The simulation steps needed for inversion are then calculated using a particular assumed velocity (or other physical property) model (5) and simultaneously activated encoded sources using the same encoding scheme used on the measured data. The result is an updated physical properties model (6) that may be further updated (7) by additional iterations.

    摘要翻译: 用于在反演过程的仿真步骤中通过使用同时编码的源来减少执行地球物理反演所需的时间的方法。 通过编码(3)一组源集合(1)来准备地球物理勘测数据,使用每组收集从非等效编码签名集合(2)中选出的不同编码签名。 然后,通过将来自每个聚集的相同接收器的所有跟踪相加,将编码的聚集相加(4),导致同时编码的聚集。 (或者,从同时编码的源获取地球物理数据。)然后使用特定的假定速度(或其他物理属性)模型(5)计算反演所需的模拟步骤,并使用与之相同的编码方案同时激活编码的源 测量数据。 结果是可以通过附加迭代进一步更新(7)的更新的物理属性模型(6)。