HeatBar Report 2008, basement heat generation and heat flow in the western Barents Sea - Importance for hydrocarbon systems

Abstract

The HeatBar project aims to determine the relative proportion of heat originating in the basement of the western Barents Sea and, as such, follows the methodologies and scientific approach developed in the course of 2005-2008 Kontiki project. We propose to shed new lights on the thermal state of the basins of the Western Barents Sea by (1) determining the heat flow and the relative content in heat-producing elements of the basement onshore nothern Norway, (2) building 3D structural models of the basement offshore based on extensive geophysical information and (3) building 3D thermal models of the basins offshore. The present report summarises the work accomplished in the framework of the HeatBar project since 2006. Dense gravity and magnetic datagrids constrained by available seismics have been used to determine the nature of the basement underlying offshore sedimentary basins and to build preliminary 2D structural models. Two drillholes have been logged for temperature in Båtsfjordfjellet and Bjørnevatn in eastern Finnmark, and, when available, core material has been used for measuring thermal conductivities. Uncorrected heat flow values at the two sites are 25 and 66 (preferred) mW\/m2 repsectively. The onshore basement in Finnmark has been extensively sampled for geochemical analyses and new heat-production data will become available very soon. Preliminary results from the very first datings of offshore basement samples are also presented. The results obtained so far will be used in the forthcoming thermal modelling effort.