用数值模式匹配算法高效仿真轴对称型散射体海洋可控源电磁响应

发布时间：2018-03-24 23:28

本文选题：海洋可控源电磁　切入点：轴对称散射体　出处：《物理学报》2017年13期

【摘要】：圆盘、球体以及球冠状体是地球物理研究中非常重要的一类散射类型.在海洋环境中,圆盘可以用于描述玄武岩基岩以及油气圈闭构造等电阻率异常体,而球冠可以近似描述某些基岩隆起或起伏地形等.这类散射体的一个重要特征是其电阻率空间分布具有轴对称性.如果能够针对这类形状的散射体研究建立一套有效的海洋可控源电磁数值模拟方法,对于认识复杂地层条件下海洋电磁响应的变化特征、研究建立相关的资料处理和解释方法具有非常重要的意义.本文根据电导率轴对称分布特征,设法用一个或多个不同半径、不同厚度的水平同心圆盘逼近这类轴对称电导率散射体,并将这些同心圆盘与海洋环境中的空气、海水、沉积层和基岩等背景介质结合,形成一个在水平方向电导率具有轴对称分布、在垂直方向又具有分层特征的水平层状非均质模型.在此基础上,应用数值模式匹配法研究水平电偶极子天线电磁场的数值模拟方法,给出位于对称轴上的水平发射天线电磁场在层状非均质地层中的半解析解,建立海洋可控源电磁响应高效算法.最后通过数值模拟结果对该算法进行检验并考察海洋可控源三维电磁响应特征.
[Abstract]:Disks, spheres and coronal bodies are very important types of scattering in geophysics. In marine environments, disks can be used to describe resistivity anomalies such as basalt bedrock and oil-gas trap structures. The spherical crown can approximately describe the uplift or undulating topography of some bedrock. One of the important characteristics of this type of scatterer is that the spatial distribution of its resistivity is axisymmetric. If a set of scatterers with this shape can be studied, a set of them can be established. An effective electromagnetic numerical simulation method for ocean controllable sources, It is very important to study and establish relevant data processing and interpretation methods for understanding the variation characteristics of ocean electromagnetic response under complex stratigraphic conditions. In this paper, according to the characteristics of axial symmetry distribution of conductivity, we try to use one or more different radii. Horizontal concentric disks of different thickness approach such axisymmetric conductivity scatterers and combine these concentric disks with background media such as air, sea water, sediment and bedrock in the marine environment, A horizontal layered heterogeneous model with axial symmetry distribution of conductivity in horizontal direction and stratification characteristic in vertical direction is formed. A numerical simulation method for the electromagnetic field of a horizontal electric dipole antenna is studied by using the numerical model matching method. The semi-analytical solution of the horizontal emission antenna electromagnetic field located on the symmetry axis in a layered heterogeneous stratum is given. An efficient algorithm for the electromagnetic response of ocean controllable sources is established. Finally, the algorithm is tested by numerical simulation results and the 3D electromagnetic response characteristics of ocean controllable sources are investigated.
【作者单位】：吉林大学物理学院;
【基金】：国家自然科学基金(批准号:41574110) 国家高技术研究发展计划重大项目(批准号:2012AA09A20103)资助的课题~~
【分类号】：P631.325

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