常规三维地面地震反演不可避免的存在多解性和分辨率不高的缺陷,而油藏地球物理阶段丰富的多尺度地震资料为减小多解性、提高分辨率提供了可能.基于贝叶斯反演理论,通过联合概率分布建立新的似然函数,将三维地面地震、VSP和井间地震三种多尺度资料有机地融合在一起,完善了多尺度地震资料联合反演框架及反演流程.模型测试及实际资料处理表明,联合反演算法有效地引入了小尺度地震资料中的高频信息对大尺度资料进行约束,反演结果在保留大尺度地震资料特征的基础上提高了分辨率,降低了多解性,同时促进了多种地震资料之间的相互匹配.
The conventional 3D surface seismic impedance inversion has the shortcomings of multiple solutions and low resolution. It is possible to overcome these shortcomings with plenty of multiseale seismic data in reservoir geophysics. Based on the Bayesian theorem, a new likelihood function is built according to the joint probability distribution. The surface seismic data, the VSP data, and the crosswell seismic data are then integrated into the joint inversion framework for multiseale seismic data, and the work flow of the joint inversion is completed and improved. The model testing results show that the high frequency information of the small-scale seismic data is introduced into the joint inversion system, which effectively improves the resolution of the inversion. In the real data processing, the global feature of the large-scale seismic data is preserved in the inversion result with apparently higher resolution. The multiplicity of solutions in conventional inversion is reduced and the characteristics consistency among multiscale seismic data is improved. These demonstrate the feasibility of the joint inversion method in practical applications.