3-D Sequential Joint Inversion of Magnetotelluric, Magnetic, and Gravity Data Based on Coreference Model and Wide-Range Petrophysical Constraints

Due to the intricate and uncertain nature of petrophysical properties, the practical application of petrophysical joint inversion poses significant challenges, and the realization of multigeophysical joint inversion methods is particularly demanding. In this study, we present an effective and versatile joint inversion method based on a coreference model and wide-range petrophysical constraints, building upon the foundation of traditional petrophysical constrained joint inversion techniques. This method is applied to the 3-D joint inversion of magnetotelluric (MT), magnetic, and gravity data. Our proposed joint inversion framework, utilizing the coreference model, decomposes the multigeophysical joint inversion into a combination of pairwise joint inversions, thereby reducing the number of weighting coefficients required. The wide-range constraints employ model transformation to introduce a priori information, while the coupling terms and range constraints facilitate the coupling of different petrophysical parameters within specified ranges, enhancing the fault tolerance of the petrophysical constraints. Model texts demonstrate the method’s ability to identify anomalies in complex interface models that traditional approaches may overlook, thereby effectively improving the inversion performance of gravity and magnetic methods. Furthermore, the validity and practicality of the method are confirmed through the processing of real measurement data obtained from the Songliao Basin, China.