METHOD FOR BUILDING VELOCITY MODELS FOR PRE-STACK DEPTH MIGRATION VIA THE SIMULTANEOUS JOINT INVERSION OF SEISMIC, GRAVITY AND MAGNETOTELLURIC DATA

摘要

A method for quantitatively evaluating and using multiple geophysical datasets and external constraints for performing velocity model building through simultaneous Joint Inversion and finalized at the improvement of seismic depth images in particularly difficult geology and hydrocarbon high-risk exploration areas is disclosed, which involved the development of techniques: - to derive an iterative depth-domain seismic imaging workflow which allows for the simultaneous use of seismic post-migration Common Image Gather residuals together with first arrival (First Break) residuals in conjunction with gravity data and magnetotelluric data; - to include in the iterative Joint Inversion workflow the setup of external a-priori constraints as well as of external constraints weighted by probability functions; - to include in the iterative Joint Inversion workflow the probabilistic evaluation of the relationships among geophysical parameters that are distinguished into analytical, empirical and structural (i.e. pattern semblance) parameters; - to allow the user for defining variable amounts of probabilistic weights to the parameters participating to the Joint Inversion.