Development of inverse modeling techniques for geothermal applications

摘要

We have developed inverse modeling capabilities for the non-isothermal, multiphase, multicomponent numerical simulator TOUGH2 to facilitate automatic history matching and parameter estimation based on data obtained during testing and exploitation of geothermal fields. The TOUGH2 code allows one to estimate TOUGH2 input parameters based on any type of observation for which a corresponding simulation output can be calculated. In addition, a detailed residual and error analysis is performed, and the uncertainty of model predictions can be evaluated. One of the advantages of inverse modeling is that it overcomes the time and labor intensive tedium of trial- and error model calibration. Furthermore, the estimated parameters refer directly to the numerical model used for the subsequent predictions and optimization studies. This paper describes the methodology of inverse modeling and demonstrates an application of the method to data from a synthetic geothermal reservoir. We also illustrate its use for the optimization of fluid reinjection into a partly depleted reservoir.