基于波动方程重建震源子波的三维全波形反演

发布时间：2019-04-27 20:49

【摘要】：提出一种基于波动方程重建震源子波的三维全波形反演方法,通过提取叠前炮集近炮检距的直达波作为波动方程求解的边界条件,重新求解波动方程,并记录震源点处的时间序列作为地震子波。该方法利用震源波场重建原理模拟震源爆炸沿地表传播的逆过程,在逆推过程中提取近炮检距直达波,避免了折射波、反射波以及潜水波等干扰。该方法只使用模型表层速度,可以有效降低对初始模型的依赖。对三维SEG/EAGE推覆体模型以及实际工区数据的测试结果表明,基于波动方程震源波场重建子波与输入子波只存在相位差异,经过相位调整后,将重建子波用于三维全波形反演,全波形反演速度接近真实速度,特别是在河道处的全波形反演结果更加可靠,观测记录与模拟记录在波形、相位等方面均有较好的对应,验证了算法的可行性与适用性。
[Abstract]:A three-dimensional full wave inversion method based on wave equation for reconstruction of source wavelet is proposed. The wave equation is resolved by extracting the direct wave of pre-stack shot set near offset as the boundary condition for wave equation solution. The time series at the source of the earthquake are recorded as seismic wavelets. The method uses the reconstruction principle of source wave field to simulate the inverse process of source explosion propagation along the surface. In the process of inversion, the direct wave of near-offset is extracted, and the interference of refraction wave, reflection wave and diving wave is avoided. This method only uses the surface velocity of the model, which can effectively reduce the dependence on the initial model. The test results of the 3D SEG/EAGE nappe model and the actual work area data show that there is only phase difference between the reconstructed wavelet and the input wavelet based on the wave equation. After phase adjustment, the reconstructed wavelet is applied to the 3D full waveform inversion. The full waveform inversion speed is close to the real speed, especially the full waveform inversion results in the river channel are more reliable. The observed and simulated records have a good correspondence in waveform, phase and so on. The feasibility and applicability of the algorithm are verified.
【作者单位】：中国石油大学(华东)地球科学与技术学院;中国石化胜利油田物探研究院;
【基金】：国家“973”重大专项(2013CB228604) 国家自然科学基金—石油化工基金联合重点项目(U1562215)联合资助
【分类号】：P631.4

【相似文献】