| Title | Uncertainty quantification of reservoir models to assess the potential of Greenfields: A case study on inclusion of multiple conceptual models |
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| Authors | M. Ikeya, K. Dekkers, C. Baxter, M. Gravatt, T, Renaud, J. OSullivan |
| Year | 2024 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Geothermal reservoir simulation, Uncertainty quantification, Resource assessment, Pico Alto Geothermal Field, Alteration model |
| Abstract | In geothermal resource developments, resource assessment has an important role especially for the decision making, since the assessment determines the possible production capacity of the field. However, because of its invisibility underground, there are many uncertainties which affect the reliability of the resource assessment. They include quality and interpretation of survey data and parameter settings on the resource size. In this study, the significance of the difference in clay cap interpretations by experts on resource assessment was investigated. Two 3D models for a geothermal field, Pico Alto Geothermal Field in the Azores, Portugal, were built with two different clay cap interpretations. The two clay caps, an “Expanded Clay Cap” and “Constrained Clay Cap” were postulated by different geologists. While these clay caps have similarities in terms of location, the estimated size differs to some extent. The results of the resource assessment, both with new method for green-field systems and with stored heat method, were compared in the two models. As a result, the difference of the clay cap distribution affected both resource assessments, but it has a smaller impact on the new resource assessment method. The model with the Expanded Clay Cap was assessed to have a larger geothermal resource by a factor of 1.3 times by the new method and 2.5 times for the stored heat method compared to the Constrained Clay Cap model. The smaller impact of the different clay cap in the new method is due to its utilization of uncertainty quantification with more detailed data such as its inclusion of simulation processes, which effectively mitigate uncertainties. In conclusion, we decided that the new method is more suitable for resource assessment in green-field geothermal systems. |