| Title | Use of an Heuristic Method and PEST for Calibration of Geothermal Models |
|---|---|
| Authors | Jericho Omagbon, Michael J O'Sullivan |
| Year | 2011 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | TOUGH2, PEST, reservoir simulation, inverse modeling, model calibration |
| Abstract | This paper discusses inverse modeling coupled with an heuristic approach for calibration of geothermal reservoir models implemented with the TOUGH2 multi-phase flow simulator. Given a pre-defined permeability distribution, the inverse modeling software suite PEST is utilized to automatically identify the values of the rock permeabilities that achieve the best fit between the model results and measured data. In order to gain further improvement in the model fit to the data, the permeability distribution is also refined in a heuristic manner by identifying the model domains that have the most effect in the model matching. This method is demonstrated using a model of a real geothermal field. The main calibration process involves the matching of the natural state temperatures taken from downhole well measurements. As a second stage, the production response of the field during the exploitation period, quantified by measurements of production enthalpies, is used to calibrate the model. |