VTI介质FFD叠前深度偏移成像方法

发布时间：2018-06-09 12:50

  本文选题：各向异性VTI介质 + 频散关系　； 参考：《石油地球物理勘探》2017年03期

【摘要】：从波动方程出发,借助声学近似假设得到VTI介质中qP波的频散关系方程并进行有理化近似,推导出不同精度的FFD(Fourier finite-difference)波场延拓算子(由频率—波数域的相移项、频率—空间域的时移项及有限差分补偿项三部分组成),基于互相关成像条件实现了VTI介质FFD叠前深度偏移成像。该偏移方法具有单程波偏移的高效性,适用于介质强横向变速情形,且考虑了介质各向异性对地震波传播的影响。在实现上述算法的基础上,通过误差分析、脉冲响应和SEG/EAGE岩丘模型成像测试验证了方法的有效性,其成像精度也比常规各向同性成像方法有明显提高。
[Abstract]:Based on the wave equation and acoustic approximation assumption, the dispersion equation of QP wave in VTI medium is obtained and the physical and chemical approximation is carried out. The wave field continuation operator (FFDF Fourier finite-difference) operator with different precision is derived (from the phase shift term in frequency-wavenumber domain). The time-shift term and the finite-difference compensation term in frequency-space domain consist of three parts. Based on the cross-correlation imaging condition, the FFD prestack depth migration imaging of VTI medium is realized. This migration method has the high efficiency of one-way wave migration, and is suitable for the case of strong lateral velocity change in the medium, and the influence of anisotropy on seismic wave propagation is taken into account. On the basis of the above algorithm, the validity of the method is verified by error analysis, impulse response and SEG / Eage dome model imaging test, and its imaging accuracy is obviously improved compared with the conventional isotropic imaging method.
【作者单位】： 中国石油大学(华东)地球科学与技术学院地球物理系;
【基金】：国家“973”计划课题(2014CB239006) 国家油气重大专项(2016ZX05002-005-07HZ,2016ZX05014-001-008HZ) 国家自然基金课题(41274124)联合资助
【分类号】：P631.4
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本文编号：1999784