MINing Environments: continuous monitoring and simultaneous inversion [MINE]

Aims

The MINE project intends to develop and implement tools to monitor mining areas and underground reservoirs, by means of continuous time series analysis and inversion, modeling fracturing processes and stress field evolution on a very local scale.

Overview

Continuous monitoring of fracturing processes in mine environments and the consequent characterization of the damage induced during mining exploitation is of primary interest both for mining engineering and civil protection. The development of improved monitoring and imaging methods is of great importance for salt mines as potential reservoirs for CO2 sequestration. Imaging tools able to handle continuous data streams and providing fast reliable information about stress perturbations and fracturing state will offer important new information to support local authorities in decision-making processes. The monitoring framework will manage continuous datasets, including acoustic, seismic, deformation and thermal data, give access to different inversionand modeling techniques, and include visualization tools. Continuous data acquisition and storage, real time processing and automated routines for data analysis will be implemented to image the time evolution of 3D structures at a very local scale. Acoustic and seismic data, whose routinely use in mining survey is typically limited to estimate location of induced microcracks and seismicity, will be more widely analyzed thanks to full waveform analysis, learning from seismological applications at larger scales. Automated processing will include triggering, source location, moment tensor and extended source parameters inversion. This knowledge can be subsequently used to derive local stress perturbations. A set of different tools, based on statistical analysis of spatiotemporal crack distribution, will be applied to identify rupture clusters and fracturing processes. Local earthquake tomography, which couples source location and seismic velocity inversions, will be applied and interpreted to image the velocity structure. Continuous recordings will also allow the application of Vp/Vs and passive image interferometry techniques, not yet used in mining monitoring, to identify major structure discontinuities and temporal variations of seismic velocities. The inclusion of data from cavity deformation, thermal and chemical monitoring will complement acoustic and seismic information, providing a multidisciplinary dataset. The coupling of different data and joint interpretation/inversion methods within a common surveying framework will finally provide high-resolution 3D and 4D tomographic images of the mining area and a continuous monitoring of fracturing processes.