A natural state model and resource assessment of Ulumbu Geothermal field

• Published in: IOP conference series. Earth and environmental science 2019-04, Vol.254 (1), p.12017
• Main Authors: Kurniawan, Iqbal, Sutopo, Pratama, Heru Berian, Adiprana, Reza
• Format: Article
• Language: English
• Subjects: Heat flow; Heat transmission; Mass flow; Monte Carlo simulation; Reservoirs
• ISSN: 1755-1307; 1755-1315; 1755-1315
• DOI: 10.1088/1755-1315/254/1/012017

Ulumbu Geothermal Field is located in Manggarai District, Flores Island, Indonesia. Downhole measurement results indicate that this field has a vapor-dominated reservoir overlying liquid-dominated reservoir with temperatures of 230-240°C. Based on the previous study it is the most promising prospect on the island of Flores with 100 MWe possible reserve. The objectives of this study are to discuss a natural state model of Ulumbu geothermal field and to assess its potential resource. The natural state model has been successfully constructed by using geological, geophysical, geochemical, and wells data from several published literature. The model can be categorized as valid since the model temperature, mass flow, and heat flow agree with the observation data. Although there might be still room for further improvements. Based on the parameters obtained from the reservoir characterization, the potential resource of the field was successfully calculated by using heat stored method with Monte Carlo probabilistic simulation. The resource calculation result indicates the field has a good capability of supporting current installed capacity with a high level of confidence.