Towed Array Seismic Exploration of the Thornqvist Zone

Abstract

Within the Deep Geothermal Energy Project in Lund, Sweden, several geophysical methods were used in order to locate the drill site for the first deep borehole. The borehole was to be placed within the Tornqvist tectonic feature. Reflection seismic was one of the geophysical methods that were used.

An alternative approach to the normal seismic survey set up was used in the project. With great success "the towed array" arrangement was performed over a considerable distance along the roads in the investigation area. The method compared to traditional seismic surveys is not only fast but also very cost efficient. Conventional seismic surveys were also performed as a final exploration effort.

This paper discusses the two methods with focus on resolution, effectiveness and also the cost benefit part of the seismic program. The results from some of the seismic survey lines carried out with the different approaches are compared and discussed.