基于岩石物理模型的最优化AVO三参数同步反演方法

An optimal simultaneous inversion method for AVO with three parameters on a petrophysics-model basis

由于反射系数线性近似公式受到小角度入射和界面弹性参数差异小的基本假设的限制,常规AVO反演在大角度入射和界面弹性参数差异大的情况下存在严重不确定性。提出了基于岩石物理模型的最优化AVO三参数同步反演方法,该方法将研究工区的特定岩石物理条件作为先验软约束融合到反射系数近似公式中,以最优反射系数近似为基础实现了最终的三参数同步反演。从应用效果看,基于岩石物理模型的最优化三参数同步反演具有更强的工区适用性,减小了常规反射系数近似公式的基本假设对反演结果的影响,而且正交基函数提高了AVO反演的可靠性。

Because the reflection coefficient approximation is limited by the basic assumptions of a low-angle incidence and small differentiation in interfacial elasticity coefficient,any conventional AVO inversion will be seriously uncertain with a high-angle incidence and large differentiation in interfacial elasticity coefficient.Therefore,an optimal simultaneous inversion method for AVO with three parameters has been developeds on a petrophysics-model basis,in which the special petrophysical conditions in a study area can be integrated into the reflection coefficient approximation as a prior soft constraint,and a simultaneous inversion with three parameters is implemented on a basis of the optimal reflection coefficient approximation.The application results have shown that this AVO inversion is higher in adaptability for study areas,and can decreasse the impacts of the basic assumptions for the conventional reflection coefficient approximation on the inversion result,and that the orthogonal basic functions can make the AVO inversion more reliable.