基于Russell近似的纵横波联合反演方法研究

PP波和PS波联合反演方法作为有效的地震技术，比单纯纵波反演精度要高，能够提高地震储层识别的精度.以Russell近似理论为基础，推导了新的转换波AVO近似公式，双层模型界面的反射特征数值模拟显示，新公式具有较高的近似精度，且具备直接反演流体因子f、剪切模量μ和密度ρ等参数的优势，有效避免间接反演带来的误差.结合纵横波联合反演理论，提出了基于贝叶斯理论的新型联合反演算法.在实际应用中，对纵波和转换波角道集进行同相轴匹配处理，综合利用纵波和转换波资料携带的信息，实现基于Russell近似的多波联合反演.模型数据和实际资料测试结果表明，反演结果与真实值或测井结果匹配度较高，证实该方法真实有效.

Joint pre-stack inversion of multiple waves based on Russell approximation

As an effective seismic technology, joint PP and PS waves inversion can obtain more accurate elastic parameters estimation than single PP wave inversion. It can enhance reservoir prediction precision. Under direction of Russell approximation theory, a new converted PS wave AVO approximate reflection coefficient is deduced. Numerical simulation of two-layer model shows that new formula has a higher accuracy. Meanwhile, it has an advantage of inverting fluid factor f, shear modulus and density directly, which can avoid generating error of indirect inversion. Combining joint PP and PS wave inversion theory, we proposed a new joint algorithm based on Bayes theory. In real application, we comprehensively used PP and PS waves information after angle gathers event matching was executed. Then, joint PP and PS wave inversion based on Russell approximation was realized. Model data and case study testing exhibited that estimated result can agree with original data or well data, proving that the new method is effective and applicative.