World Geothermal Congress 2020+1
March - October, 2021

Use of Automated QEMSCAN Technique for Mineral Quantification in Reykjanes Geothermal Field, Iceland


[Equinor ASA, Norway]

Mineralogical analyses have been performed on 36 core samples and 4 cuttings samples from the RN-15/IDDP-2 well that was deepened by the Iceland Deep Drilling Project (well IDDP-2). RN-15/IDDP-2 drilled to 4659m depth, is the deepest geothermal well drilled in Iceland. The samples analyzed in this study are from the three depth intervals 3021m to 3870m, 4090m to 4310m and 4634m to 4656,99m. Polished thin sections were prepared from all the core samples. To identify the mineralogy of the samples both light microscopy analyses and QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) have been applied. The advantage of utilizing the QEMSCAN technique is the possibility of both quantitative mineral analyses and mineral mapping at microscale. In addition, SEM/BSE mapping have been performed to reveal the micro-porosity of the metamorphic rock samples from the thin section material. The rock samples analyzed show a change in mineralogy with depth corresponding to granulite facies in the deepest depth interval through amphibolite facies and into greenschist facies in the shallowest depth interval. Ore mineralogy in veins was detected on all depth levels. This study is part of a multidisciplinary study that aims to better understand all aspects of geothermal drilling and production. The mineralogical data will be applied in evaluating the effect of mineralogical processes in well production and well stability. Further, the results from this study give a better understanding of mineral processes and properties that are important in the process of identifying risks when utilizing oil industry knowledge and equipment in geothermal drilling processes.

        Topic: Geochemistry Paper Number: 14052

         Session 8P: Poster 2 [Tuesday 11th May 2021, 11:00 pm] (UTC-8)
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