Method for simultaneous inversion processing of well log data using a plurality of earth models

摘要

A method of determining a plurality of formation models each of which will simulate the response of a well logging instrument. A measured response of the well logging instrument is used to generate an initial model using inversion processing. A response of the instrument to the initial model is synthesized. A singular value decomposition is performed on the synthetic response to generate eigenparameters of the initial model. Eigenparameters having the least significant overall contribution to the synthetic response are sequentially substituted with linear equations representing prior constraints on the initial earth model. A linear system, including the remaining ones of the eigenparameters and the linear equations is solved so that the eigenparameters are preserved exactly and the linear equations satisfy a least squares fit. An additional synthetic instrument response is generated for each solution to the linear system which falls below a predetermined error threshold. The additional instrument responses are compared with the synthesized response to the initial model. The one of the solutions to the linear system which represents an earth model providing minimum misfit with respect to equations representing the prior constraints is selected as the best fit model.