Developing New Concepts for the Exploration of High and Medium Enthalpy Geothermal Reservoirs, the I-GET Project

Abstract

The project I-GET is aimed at developing an innovative geothermal exploration approach based on advanced geophysical methods. The Project Acronym stands for Integrated Geophysical Exploration Technologies for deep fractured geothermal systems. The objective of the project is to improve the detection, prior to drilling, of fluid bearing zones in geothermal reservoirs. This new approach has been tested in four European geothermal systems with different geological and thermodynamic reservoir characteristics: in metamorphic (Travale, Italy) and volcanic rocks Hengill, Iceland), and two in deep sedimentary rocks (Gro?- Sch?nebeck, Germany, and Skierniewice, Poland). Integration of different geophysical approaches is the key concept of the project. To this end, seismic and magnetotelluric data were acquired in the test sites, and new acquisition and processing techniques were developed to solve problems related to the particular target such as high temperatures, anisotropy, phase condition, etc. The static and dynamic three-dimensional model of geothermal reservoirs will be reconstructed by means of all the data acquired. The input of the results of new geophysical prospecting into reservoir modelling is a crucial test of the quality of the new exploration method. Simultaneously to in situ data acquisition, petrophysical and geomechanical properties of the investigated rocks are defined by laboratory measurements. With respect to the high enthalpy sites, elastic and electric rock properties have been determined at the steam/liquid transition of the pore fillings. The validity of the laboratory and simulation results will be verified by the new field experiments. The ultimate goal is the development of an efficient, lowcost exploration method, by taking advantage of the strengths of different disciplines and combining them to an integrated approach.