Abstract:
This paper presents the results of a geophysical survey using downhole seismic and sonic log. Both tests are based upon the propagation of the P-wave (compressional) and the S-wave (shear) in the lithologies, resulting an excellent data vertical resolution. The downhole test, using a seismic source positioned on the surface and the geophone situated inside a borehole, provides a resolution of about one meter. The sonic log, in turn, allows to get seismic velocities with a vertical resolution of about tens of centimeters. Both data was collected in two wells, eighty meters deep, located in the Sedimentary Basin of São Paulo, drilled in soil (layered sand-clay) and in rock (crystalline basement). A VP and VS model has been proposed based on the results of the geophysical data acquisition.
Reference:
GANDOLFO, Otávio Coaracy Brasil; BORGES, Stefani Alves; LIMA, Maria Carolina Silva; BIRELLI, Carlos Alberto. Determinação do perfil de velocidades das ondas P E S, em litologias da bacia sedimentar de São Paulo, utilizando ensaio sísmico downholee perfilagem sônica. In: CONGRESSO BRASILEIRO DE GEOLOGIA DE ENGENHARIA E AMBIENTAL, 16., 2018, São Paulo. Anais.. São Paulo: ABGE, 2018. 10 p.
Access to the article on the Event website:
http://www.schenautomacao.com.br/cbge/envio/files/trabalho_125.pdf
This paper presents the results of a geophysical survey using downhole seismic and sonic log. Both tests are based upon the propagation of the P-wave (compressional) and the S-wave (shear) in the lithologies, resulting an excellent data vertical resolution. The downhole test, using a seismic source positioned on the surface and the geophone situated inside a borehole, provides a resolution of about one meter. The sonic log, in turn, allows to get seismic velocities with a vertical resolution of about tens of centimeters. Both data was collected in two wells, eighty meters deep, located in the Sedimentary Basin of São Paulo, drilled in soil (layered sand-clay) and in rock (crystalline basement). A VP and VS model has been proposed based on the results of the geophysical data acquisition.
Reference:
GANDOLFO, Otávio Coaracy Brasil; BORGES, Stefani Alves; LIMA, Maria Carolina Silva; BIRELLI, Carlos Alberto. Determinação do perfil de velocidades das ondas P E S, em litologias da bacia sedimentar de São Paulo, utilizando ensaio sísmico downholee perfilagem sônica. In: CONGRESSO BRASILEIRO DE GEOLOGIA DE ENGENHARIA E AMBIENTAL, 16., 2018, São Paulo. Anais.. São Paulo: ABGE, 2018. 10 p.
Access to the article on the Event website:
http://www.schenautomacao.com.br/cbge/envio/files/trabalho_125.pdf
