Two Massive Hydraulic Tests Completed in Deep KTB Pilot Hole

Abstract

The German Continental Deep Drilling Program (KTB)boreholes in Windischeschenbach, Bavaria, Germany have revealed a wealth of geoscientific data during the years of pre-drilling surveys (1984–1986), the drilling phase (1987–1994), and the subsequent deep-crustal laboratory phase (1995–2000, e.g. Emmermann & Lauterjung, 1997). In 2001, a new series of experiments were launched within and around the two KTB boreholes, the 4.0-km-deep pilot hole (KTBVB), and the 9.1-km-deep main hole (KTB-HB; Fig. 1). Theseexperiments address the spatial extension of fluid flow and fluid systems in the Earth's crystalline crust, their impact on physical rock parameters, rheology, the dynamics and mechanical stability of the crust, and the transport of soluble matter. Studies of these parameters under in situ conditions are of fundamental geoscientific and societal interest in areas such as the optimal use of fluid and thermal reservoirs, the safe disposal of critical wastes, and understanding seismogenesis, particularly in connection with large lake reservoirs

Microseismicity induced during fluid-injection: A case study from the geothermal site at Groß Schönebeck, North German Basin

“…Shapiro et al (2006) showed that only positive pore pressure perturbations induced seismicity and they confirmed that fluid pressure diffusion is a dominant mechanism of seismicity triggered by fluid injections in KTB. Kümpel et al, (2006) analyzed the seismicity related to injection test performed at KTB in [2004][2005]. They found that the seismicity was much weaker than in previous experiments.…”

Stress Field of the Earth’s Crust

“…The result of the 1-year production test (2002)(2003) and the 10-months injection test (2004)(2005) are summarized in Kümpel et al (2006). During the 10-months injection test, a total of 84,600 m 3 of fresh water was pumped into the open hole section of KTB-VB.…”

Land uplift due to subsurface fluid injection

“…A water injection experiment intended to study deformation of the upper crust, improve knowledge of coupled hydrogeomechanical processes and characterize the affected subsurface porous medium was performed from June 2004 to April 2005 in the Upper Palatinate, Eastern Bavaria, Germany (Kumpel et al, 2006). Water was injected at a rate of about 290 m 3 /day to a total of 84,000 m 3 through an open hole that was 3850-4000 m deep.…”