【摘要】 叠前地震数据反演可以得到比常规叠后波阻抗反演更丰富、更有效的岩性信息,但叠前数据体的噪声及其它因素严重影响了AVO反演的稳定性,如何评估AVO反演结果的可靠性显得尤为重要.本文从贝叶斯理论出发,假定均匀先验分布、高斯噪音分布,推出不确定性分析方程,利用协方差矩阵中的方差描述反演问题的不确定性,模型研究显示反演不确定性与叠前信噪比、纵横波速度比、覆盖次数及反演采用的角度范围相关,方法预测的反演误差可定量解释反演结果的可靠性,为解释人员提供有效的质量监控手段.更多还原

【Abstract】 More abundant and effective lithologic information can be obtained from inversion of pre-stack data in comparison with from ordinary post-stack impedance inversion.The noise and other factors of pre-stack data can heavily influence the stability of the inversion problem.So it is very important to predict the reliability of AVO estimates.Based on Bayesian theorem,it is initially assumed that the prior probability distributions are uniform and the noise is independent and Gaussian.In this case,the uncertainty analysis equation can be obtained.The variance in parameter covariance matrix can be used to investigate the uncertainty in the problem.The modeling studys show that the uncertainty of AVO inversion is a function of the prestack noise,the ratio of the P-to S-wave velocity,the fold and the range of angle available for inversion.The predicted errors by the method give interpreters tools to help quantify the reliability of their AVO interpretation.更多还原