ESTIMATION OF DEEP SUBSURFACE STRUCTURE IN EUROPEAN HOT DRY ROCK TEST SITE, SOULTZ-SOUS-FOReTS, FRANCE, BY USE OF THE AE REFLECTION METHOD

摘要

Recently, the further Hot Dry Rock (HDR) development toward great depth has been started at the Soultz-sous-Forets, France. Therefore the understandings deeper subsurface structure is taking on more important role. In this paper we present an estimation of deep subsurface structure in the Soultz HDR site by applying a type of reflection technique which we call the AE reflection method in timefrequency domain, where induced acoustic emission (AE) signals are used as wavesource. First, we mention the AE reflection method in time-frequency domain briefly. Next, we show the three-dimensional deep imaging which includes some meaningful reflectors. Then we precisely relate detected reflectors along the trajectory of well GPK-1 and deepened GPK-2, and compare the AE reflection method with other borehole observations. The results indicate a good agreement with distribution of fracture zone in GPK-1 and corresponds with possible fracture zone from a synthetic petrographic log derived from microscopic examination of cuttings during deepening of GPK-2.