Monitoring of geothermal reservoirs by hybrid gravimetry

Abstract

Time-lapse gravity is a monitoring tool to investigate underground mass redistributions and hence finds a potential application to follow a geothermal reservoir both in its natural state or undergoing man-made stimulations. Several experiments have introduced the concept of hybrid gravimetry which is the optimal way to combine different types of instruments and techniques of measurement. In particular, hybrid gravimetry uses a reference station where gravity is continuously recorded with a relative gravimeter and regularly checked with absolute gravity measurements, as well as repetitions of a micro-gravimetric network of several satellite stations in the vicinity of the reference one.