Exploration for EGS fields: innovative approach in deep geothermal contexts and R&D strategy

Abstract

TLS-Geothermics has undertaken its own exploratory assessment and strategies to identify technology options and geological models which could improve substantially the success of exploration in deep non-conventional geothermal systems which we consider having the potential to unlock vast renewable energy resources, and further potential to yield results that may benefit many industries and investors. As far as the installed electricity capacities, these geological contexts still remain the main supplier in the world compared with the hydrothermal and volcanic contexts. Our exploration strategy focused narrowly on R&D by setting closed partnerships with academic researchers and independent technological companies on their applied research and deploying their innovative technologies on the field. Beyond technology, a documented geological and structural “a priori” model is required to choose the suitable methods and select the appropriate geophysical methods. Whatever the technology used, it nevertheless should comply the geological model and subsequently geodynamic environments, which is the key issue to characterize thermal anomalies typology, assume geometry of structural elements and determine petrophysical properties of the geothermal system. Passive geophysical methods are commonly used in geothermal activities since years and provide a range of methods. Depending of these geological contexts to be enlightened, appropriate methods are going to be revisited and performed on field since 2014 to comply with the cost effectiveness, relied on the petrophysical and petro elastic conditions of the rocks and locate the origin of the thermal anomaly. Nevertheless several main requirements have to be implemented which significantly must improve the identification of resource before drilling:
-improvement of existing advanced technologies especially on high resolution passive geophysics and 3D depth imaging,
-develop emergent geological concepts supported by worldwide reference cases
-enhance geophysical high resolution networks and deploy dense broadband seismic experiment,
-combine reliable technologies to enlighten different structural elements of the geothermal system through depth (from shallow subsurface to deep lower crust),
-develop combined methods by 3D joint inversions to enhance 3D model of high density broad band soundings (seismic and non-seismic methods).
-proving efficiency of noise-based seismic tomography for shallow and deep images.
In this perspective, TLS Geothermics, which is a 2012-created engineering company and developer, is currently developing a new approach on conducting collaborating research projects dedicated to this industrial strategy in order to unlock and answer scientific questions and optimize geothermal exploration in these different areas and analogue regions which was studied (see Poster at the EGC2016). Some geological and geophysical aspects of these approaches will be displayed at EGC2016 (See posters M.Bellanger et al, and J-M.Ars and al.) particularly on 3D joint inversion methods, seismic tomography with continuous records of ambient noises and new paradigm on structural context.