Simulação e inversão tomográfica acústica em testemunhos de poço.

Abstract

Acoustic tomography of cores can be rather useful on identification and quantification of several petrophysics attributes. Time-traveling tomography technique involves the inference of local acoustic velocity from the time of traveling of waves between a large number of pairs source-receiver. With aim of analyze the special distribution of acoustic velocities in well cores, it was simulated a system to execute elastic tomography in cores, comprising a model of CT scanner and a set of computational programs developed to detected the first wave arrival times, invert all data acquired from the CT scanner and generate the velocity maps (tomograms). In this model, the transducers perform data acquisition with a dynamic positioning in 36 different positions over the sample perimeter. This assembly of data acquisition result on the register of 684 traces for each tomogram. Inversion programs used to generate the tomograms have been tested in models of cores simulated synthetic and numerically whose expected tomograms are previously known. The Inversion programs are proving able to reproduce, approximately, the theoretical models of cores, although there is a limitation given by the partial assumption that the trajectory of the rays occurs linearly.