改进的大地电磁与地震资料联合反演方法在黔中隆起区的适用性研究

Adaptability research on improved joint inversion method of magne-totelluric and seismic data in middle Guizhou Uplift

为了解决复杂地质问题以及大地电磁(MT)与地震资料联合反演存在的问题,结合已有研究成果,利用基于不同物性参数随机分布共网格模型的大地电磁与地震资料同步联合反演技术,对黔中隆起地震资料品质低,且构造复杂的典型地段的实际资料进行了联合反演。根据研究区实际情况,利用两种地质解释方案建立了联合反演的初始速度模型和电性模型,并进行了联合反演和综合解释。将反演结果与已有方法得到的结果进行对比表明,改进的联合反演方法适用于物性剧烈变化的复杂地质模型条件,在先验信息的约束下,改进后的联合反演方法在确定复杂物性条件下的电性和速度结构方面能够提供更合理的解释方案和物性参数,为目前研究区难以推断的古生界目的层的分布及基本构造特征的判断提供了参考依据和技术手段。

In order to solve the problems existing in joint inversion of magnetotelluric(MT) and seismic data,combining with some research achievements,a synchronous joint inversion of MT and seismic data based on common gridded model with random physical property distributions was proposed and applied to inverse the actual data in the area with complex structures of middle Guizhou uplift. In terms of the conditions of the area,two geologic interpretation schemes were used to establish initial velocity model and resistivity model,carry put joint inversion and integrated interpretatioa The obtained results were compared with the results from existing method,which showed that the improved joint method is suitable to the complex geologic model with strong variable physical properties. Meanwhile,with the restraint of prior information,the improved joint inversion method can provide more reasonable interpretation scheme and physical parameters to identify electric properties and velocity structure with complex physical properties, which provides basis and supports for the determination of Paleozoic target and basic structural features in the research area hard to be identified.