Sensitivity of Temperature Predictions in Basin-Scale Hydrothermal Models

Abstract

In extensional geothermal systems such as those in the Basin and Range Province, fluid-bearing fracture zones are known to be associated with structural complexity based on the locations of thermal springs. However, characterizing geothermal resource potential and reducing exploration risk, particularly in systems where there are no surface manifestations of the hydrothermal system, remains challenging. In this paper, we examine the relative impact of numerical model parameters on temperature predictions of regional-scale hydrothermal systems using coupled fluid and heat transfer modeling. The numerical model is composed of three primary domains: (1) crystalline basement rock, (2) sedimentary basin, and (3) range-bounding fault zone. Parameters in the Monte Carlo simulation include material properties, model geometry parameters, and boundary conditions. Using Monte Carlo simulation, 800 models were generated and solved while varying the above parameters, resulting in a broad range of model responses. Distance-based sensitivity analysis is used to assess the relative importance of model parameters in order to gain insight into the factors that drive thermal upwelling in regional hydrothermal systems.