3D Seismic Survey for a Petrothermal Research Project in Crystalline Rocks of Saxony

3D seismic measurements have been performed in 2012 to explore a petrothermal reservoir in a crystalline environment (granite intrusion, metamorphic cover) within the Erzgebirge in Saxony. The intention and challenge is to image and characterize a steeply dipping fault zone and therewith potentially permeable fracture zones at target depths of 5–6 km and temperatures well above 150 °C. The vibroseis technique was used in the experiment, accompanied by a special explosive seismic experiment. Common-reflection-surface (CRS) processing with subsequent post-stack and pre-stack time migration was highly successful. A rich repertoire of structures within the granite pluton has been imaged. Many of these structures are steeply dipping normal faults and their conjugate faults with high impdedance contrasts and subhorizontal reflectors at the base of the granite.

The 3D seismic technique has been proven as an indispensable tool to define an optimum drill path in a crystalline environment.