APPLICATION OF A NEW TECHNICAL OF ACOUSTIC TOMOGRAPHY FOR THE VISUALIZATION AND ESTIMATION OF THE MICROFRACTURES IN OUTCROP SAMPLES

Abstract

This work presents the development of a methodology to estimate microfractures density in rocks, using acoustic tomography technique. The piezoelectric crystals were used as transductors for the generation of the acoustic shear kind waves, through study cores. The propagation time of the wave is obtained using digital signal processing in MATLAB and finally the distances of each paths is obtained, thus the wave velocity values are stored in numerical arrays. The technique used in this work is to perform acoustic tomography in function of the shear wave velocity, where the rock matrix and microfractures are differentiated and analyzed from contrasts of velocities. The tomographic images are generated through rendering matrices of velocity in MATLAB. In order to validate this research was necessary to use synthetic cements plugs as controlled models, where the discontinuity was simulated through hollow inclusions made with rubber prototypes; finally the obtained results show a maximum of 7.06% of error, baseing the reliability of the generated technique.