TECHNO ECONOMY STUDY FOR GEOTHERMAL DEVELOPMENT SCENARIO SELECTION USING NUMERICAL AND FINANCIAL MODEL

• Main Author: Lesmana, Ade
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43866
• Institution: Institut Teknologi Bandung

The tender stage of Geothermal Working Area in Indonesia is conducted after the preliminary survey or preliminary survey and exploration were performed, therefore the available data will be limited. On the other hand, the prospective developer who takes part in the tender must submit the tender’s proposal which describes the plan of development strategy and investment cost requirement. Both conditions can be formulated by integrating numerical modeling and financial modeling. These methods are able to accommodate the uncertainty factor to reduce the level of risk that might arise. This study aims to determine the optimum development strategy of the geothermal working area by combining numerical modeling and financial modeling. The output of both methods is a feasibility study of geothermal working area development. As the object of the research, The Tompaso field in North Sulawesi was chosen due to the available data from the publication. The Tompaso field model was built using the TOUGH2 simulator and the output was validated using observation data from 10 wells. The deviation of temperature and pressure of the models against observation data ranges from 4.1-20.2°C and 1.2-18 Bara respectively, so that the model can be stated to have reached the natural state condition. The natural state model was the basis for calculating the proven reserve using dynamic deliverability method and approach of experimental design Box-Behnken 2nd order. The result of 27 simulations generated a proxy equation that was combined with Monter Carlo simulations so that a proven reserve of the Tompaso field is 58.5 MWe (P10). Three development scenarios were selected and simulated to determine the requirement of production, reinjection and make-up wells for each strategy. The economics of each scenario was evaluated using financial modeling with Monte Carlo probabilistic approach. The result obtained was the development of 1 × 40 MWe at the Tompaso field, giving the best IRR probability, which is 13.76% (P10).