Project Details
Projekt
Modelling of steady-state vs transient heat transfer in the COSC-1 drillhole, Central Sweden
Applicant
Professor Christophe Pascal, Ph.D.
Subject Area
Palaeontology
Geophysics
Geophysics
Term
from 2015 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 270822516
This proposal is linked to the Collisional Orogeny in the Scandinavian Caledonides (COSC) project funded by ICDP. COSC-1 was drilled and fully cored near the town of Åre, Central Sweden in 2014. Reached vertical depth was ~2.5 km and core recovery nearly 100 percent. This project is a contribution from the COSC Geothermal Group, led by the applicant and the aim of this proposal is to request a 3rd year of funding in order to complete the PhD project. We wish to contribute to knowledge on geothermal regimes of Precambrian shields. Deep scientific drillholes in such geological environments are very seldom. To date only two drillholes have delivered detailed analyses with opposite conclusions concerning the impact of advection in deep cratonic crust. Hence, a major objective is to characterise the relative contribution of transient advective heat flow. We postulate that fracture permeability is sufficient to promote significant advection in Precambrian shields. However, topographic heads are absent in the general case, implying a (quasi) steady-state geothermal regime. Being located in a mountainous area of a stable Precambrian shield, the COSC-1 drillhole will furnish optimal data to test our working hypothesis. In order to reach this specific goal we planned to carry out the following tasks during the first two years of the project: (1) to measure thermal properties on 100 core samples, (2) to analyse borehole logs in order to construct a lithological/petrological profile and (3) to calculate the heat flow density profile for COSC-1 and isolate eventual transient signals, including advective and paleoclimatic ones. For the 3rd year (i.e. this proposal) we propose to build a 3D geothermal model based on the acquired data and to constrain the geothermal regime around the COSC-1 well.
DFG Programme
Infrastructure Priority Programmes
Co-Investigator
Professor Dr. Jörg Renner
