Item

Abstract

Borehole measurements or downhole logging is a powerful method to in-situ gain quasi-continuous profiles of physical, chemical and structural rock parameters with high depth accuracy. It is widely used in both academic research and commercial exploration for oil and gas, mining industry, geothermal and water engineering. The GFZ section Scientific Drilling facilitates logging in two ways, first through service and applying a set of downhole instruments and second through developing novel methods and tools. Logging support is provided to scientific projects and covers assistance with planning and logistics of downhole logging programs, logging service through operating a versatile set of own downhole sondes, including geophysical and structural logging tools, a seismic chain and a fluid sampler. In order to expand the possibilities of in-situ borehole information new tools are developed jointly with academic and industrial partners. The most advanced sonde development strives to image geological structures by using high-resolution borehole seismics to explore hydrocarbons or geothermal resources by detecting thin layers and faults. The SPWD (Seismic Prediction While Drilling) borehole prototype sonde combines seismic sources and receivers in one device to improve the resolution. Two downhole test sites, the KTB-Deep Crustal Lab in Windischeschenbach and the GFZ Underground Lab in the mine “Reiche Zeche” in Freiberg offer unique in-situ conditions for experiments and tests of the borehole equipment.