Geothermal evaluation of the Geldinganes area in SW-Iceland and proposal for assessment of the Shivert hot spring area in Mongolia

Abstract

This report deals with evaluations of two geothermal fields in different parts of the world. Temperature gradient data from 16 exploration wells, and well-test results from a prospective geothermal area in SW-Iceland, the Geldinganes area, have been re-evaluated. The results indicate an up-flow of about 105°C water along a near-vertical SSW-NNW trending geological structure from depth under the southern part of Geldinganes up to shallower formations near the north coast of the peninsula. This result contradicts an earlier conceptual model of the Geldinganes field and may explain why a production well, RV-43, directionally drilled to the north-northeast in 2001 was not successful. The permeability-thickness of the Geldinganes reservoir is estimated to be 1.5-3.0 Darcy-m. Predictions by a lumped parameter model indicate that the production potential of well HS-44 in the southern part of Geldinganes is in the range of 7-20 l/s. Preliminary evaluation of the Shivert hot spring area in central Mongolia that involved temperature data from six exploration wells indicates a clear up-flow of 80-100°C water along a high-permeability vertical fracture. The Shivert area is believed to have considerable potential, but this resource needs to be carefully and thoroughly assessed. It is expected that the methods that have been successfully applied in the Geldinganes area and other low-temperature geothermal fields in Iceland are equally applicable in Mongolia. Therefore, the experience in low-temperature geothermal exploration...