贝叶斯三参数低频软约束同步反演

Bayesian prestack three-term inversion with soft low-frequency constraint

贝叶斯叠前反演通过引入三参数反射率的先验分布,可以提高三参数反射率反演的稀疏性和垂向分辨率,进而达到高分辨率反演的效果。然而在对实际资料进行试算时,由于随机噪声的存在,单一的稀疏约束项并不足以保证反演结果的稳定性。通过引入低频软约束项,即反演结果的低频和模型的低频之差的L_2范数达到最小,可以提高反演结果的鲁棒性,使贝叶斯三参数同步反演在实际资料的适用性增强。与平滑正则约束三参数反演相比,本文方法既能获取稳定的低频信息,同时也不会降低纵横波速度比反演结果的垂向分辨率。

With priori information of three-elastic-parameter reflectivity, Bayesian prestack inversion can obtain high resolution sparse-spike results. But in real data test, the single sparse-spike constraint may make the inversion unstable. So other constraints should be added to stabilize the inversion. A soft low frequency constraint, minimizing the L2norm of the low frequency difference between the inversion result and the model, can improve the robustness of the inversion. Comparing with the smooth constraint, the proposed approach can obtain stables low frequency of the inversion result while the resolution of the vP/vSresult has remained the same. © 2016, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.