关键词: 倾斜地层, 瞬变电磁, 一维反演, 加权横向约束反演, 拟二维反演

Abstract: The traditional single-set one-dimensional(1D) inversion is the most widely used technique for the processing and interpretation of transient electromagnetic data in coal mines. However, this approach becomes inadequate when the stratum exhibits a significant dip, as the single-set horizontal layered model fails to accurately represent the electrical distribution characteristics. To address this limitation, we employ the weighted laterally-constrained inversion method to constrain the layer interface depth and incorporate the difference in geoelectric parameters between adjacent measurement points into the objective function as a constraint term. We describe the transient electromagnetic 1D forward and inversion theory, and detail the inversion method with weighted lateral constraints. The influence of the weighting factor on inversion results is analyzed using the H-type and K-type models with varying inclinations. Compared with  the traditional 1D inversion, the weighted laterally-constrained inversion is a pseudo-2D inversion method by establishing   layer parameters and  depth-weighted constraint equations  and synthesizing total inversion equations. The obtained resistivity profiles exhibit strong agreement with actual models and demonstrate good longitudinal and transverse continuity. The employed method effectively restores the electrical distribution of inclined strata, and the inversion results match the actual geological data.

Key words: inclined strata, transient electromagnetic, one-dimensional inversion, weighted laterally-constrained inversion, pseudo-2D inversion