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

Abstract

Recently, the further Hot Dry Rock (HDR) development toward great depth has been started at the Soultz-sous-ForÍts, 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 time-frequency 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..