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声反射成像测井方法和仪器近来成为勘探地球物理界的新研究热点.但有利于成像的反射波信号与井中的模式波叠加而难以分离出来.为了改进仪器设计,研究更有效的数据处理和解释方法,必须用以波动方程为基础的数值模拟方法来精确描述声反射成像测井的波场.为此建立了非均匀交错网格、加PML吸收边界的、能够用于正交各向异性介质的3维有限差分数值模拟方法和并行算法程序.将其应用于典型各向同性和各向异性地层中反射声波成像测井的三维波场模拟,并与已公开发表的应用离散波数方法的相应结果对比,证明了此方法正确、算法高效.模拟的波场动态范围能够大于60dB,计算速度比常规算法提高了3.5倍.这些技术能够正确、有效地模拟大尺度(在10m左右)、较高频率(10kHz左右)的反射声波成像测井波场.为我们研究声反射成像测井仪器和资料处理解释方法提供了有力的定量分析工具.
Acoustic reflection imaging logging methods and instruments have recently become new hot spots in the exploration of geophysics, but it is difficult to separate the reflected wave signals that are advantageous for imaging from the mode waves in the wells. In order to improve instrumentation design and to study more efficient data processing and To explain the method, the wave field of acoustic reflection imaging logging must be precisely described by using the numerical simulation method based on the wave equation. For this reason, a non-uniform staggered grid is established, and the PML absorbing boundary can be used for orthogonal anisotropy Dimensional finite difference numerical simulation method and parallel algorithm program of the medium were applied to the three-dimensional wavefield simulation of the reflection acoustic imaging logging in the isotropic and anisotropic formations of a typical type, and compared with the published method of discrete wave number method The results show that this method is correct and the algorithm is efficient.The dynamic range of the wave field can be greater than 60dB and the computational speed is 3.5 times higher than that of the conventional method.These techniques can simulate the large-scale (about 10m) High-frequency (about 10kHz) reflected acoustic imaging logging wavefield. For our study of acoustic reflection imaging logging tools and data processing and interpretation methods For a powerful tool for quantitative analysis.