A 3D Geological Static Field Model of the Krafla Geothermal Area, NE-Iceland

Abstract

3D geological static field modelling is a useful tool to compile and summarize surface and subsurface data and their interpretations. The modelling purpose is to gain a better understanding of the nature and characteristics of the geothermal system and minimize risks for future drilling targets. Geothermal systems behave differently, and priorities of data vary in every case. The workflow approach allows documentation of each step during the modelling process that can be revised if parameters change with new data acquired. The Krafla geothermal field in NE-Iceland has been explored since 1969. A large variety of datasets have been collected from 47 boreholes. Six comprehensive conceptual models have been put forward throughout the field’s history. The various datasets provide the basis for a geological static model, primarily sub-divided into two groups: (1) geophysical surface data, and (2) subsurface borehole data. By recording the work already performed and the evolution of existing knowledge, the resulting workflow describes in general how to bring together multidisciplinary interpretation results, which in turn highlight areas of uncertainty and the future work required. The different datasets from Krafla have been tied together in order to do a joint-interpretation of the structural pattern in Krafla and the link to production patterns across the field.