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叠前地震反演能够提供更加丰富的地球物理信息,但影响其反演精度的因素较多。设计了包含不同速度特征的地质模型,再对基于地质模型提取的地震模型数据体进行反演,将反演结果与理论值进行误差对比,分析了初始约束模型、信噪比、反演子波选取、反射系数计算公式选择对叠前地震反演精度的影响。结果显示,精度高的初始约束模型反演结果好于精度低的初始约束模型;信噪比大的地震数据体的反演结果优于信噪比小的地震数据体;选取的反演子波与地震数据主频的匹配程度越近似,反演精度越高;可以选取适用条件相对较合理的Zeoppritz方程作为反射系数计算公式。地质模型数据与实际资料反演结果对比表明,构建与实际地质模型弹性属性接近的反演初始参数模型,对采集数据进行滤波去噪和修饰处理提高地震资料信噪比,通过测井和地震资料提取主频与地震数据相匹配的反演子波以及反射系数计算公式等参数的合理选择有利于提高叠前地震反演精度。
Prestack seismic inversion can provide richer geophysical information, but there are many factors that affect the accuracy of inversion. The geological model with different velocity characteristics is designed, and then the seismic model data body extracted based on the geological model is inverted. The error between the inversion result and the theoretical value is contrasted. The initial constraint model, signal-to-noise ratio, The influence of selection formula of reflection coefficient on seismic inversion accuracy of prestacking. The results show that the inversion result of initial constraint model with high precision is better than that of initial constraint model with low accuracy. The inversion result of seismic data body with large signal-to-noise ratio is better than seismic data body with small signal-to-noise ratio. And the closer the frequency of the seismic data matches, the higher the inversion accuracy is. The Zeoppritz equation with relatively reasonable conditions can be chosen as the reflection coefficient calculation formula. The comparison between the geological model data and the actual data shows that the inversion initial parameters model is established which is close to the elastic properties of the actual geologic model. The collected data are denoised and modified to improve the SNR of the seismic data. Through logging and seismic data The reasonable choice of parameters such as inversion wavelet matched with seismic data and the formula of reflection coefficient is helpful to improve the accuracy of prestack seismic inversion.