A Bayesian Joint Inversion Of Magnetotelluric And Gravity Based On The Wide-range Petrophysical Constraints

In the actual geophysical exploration.A comprehensive geophysical approach is often used for detection.The joint inversion of different methods is very important.MT and gravity are two widely used geophysical prospecting methods.Combine the advantages of MT and gravity.The resistivity and density parameters of underground geologic structure can be inversed.It makes the inversion result more accurate and reliable.the physical properties of the rock is one of the methods for the mutual constraint between different physical parameters in geophysical joint inversion.In the joint inversion of MT and gravity.the method between the point to point mapping different petrophysical parameters is not accurate.It is difficult to reflect the real space correspondence between physical parameters.The study of the wide range of rock property constraints becomes particularly important.Bayesian inversion theory provides the basis for the multi-solution of inversion results.It is a research hotspot in joint inversion field.In this paper,The bayesian joint inversion of MT and gravity data is carried out based on the wide range of petrophysical constraints.In this paper,Bayesian inversion theory is firstly introduced into the joint inversion of the MT and gravity based on the rock property constraints.The solution is expressed by the posterior probability density distribution of different physical parameters.The maximum posterior solution,the mean solution and the traditional final iterative solution of the resistivity and density are extracted.Then the method between the point to point mapping of rock physical is extended to the real space mapping between physical parameters.To realize the wide range physical properties of the rock and bayesian inversion theory.The application scope of this technology is expanded.The method is verified by model test and measured data processing.Model test: the maximum posterior solution and the mean solution can better restore the real model than the final iterative solution.The objective function based on the petrophysical constraint scheme can stabilize and converge earlier.The fitting effect of gravity anomaly is also better.And it can increase the coupling degree between resistivity and density.This method is applied to the actual data of Xia Yangzi area.The obtained geological information and tectonic information are consistent with previous interpretation results.The practicability and validity of this method are verified.