Mixed integer optimization model for utilizing a geothermal reservoir

Abstract

Low temperature geothermal resources provide hot water that is commonly used for space heating various or industrial activities. The geothermal resources are in most cases renewable and can be utilized by current and future generations if constraints regarding sustainability are respected. In this work, we propose an innovative model to optimize the present value of profit from utilizing low temperature geothermal resources subject to operational and sustainability constraints. A fundamental part of the model is a sufficiently accurate and efficient reservoir model which simulates pressure changes (drawdown) in the reservoir with respect to utilizing levels. The approach proposed here seamlessly integrates a discretized lumped parameter model of the reservoir with a mixed integer linear program of the utilizing operations. The model is validated with real data from 26 years of utilizing a geothermal reservoir in Iceland and results include different scenarios for illustrating the use of the model. The approach proposed in this paper has the potential to improve current decision-making in this area as it helps studying utilizing strategies in a thorough manner.