Geological mapping of the near seabed section on central Campos Basin through elastic attributes extracted from 3D reflection seismic data

Abstract

A method of geological mapping of the near seabed section is presented in that such a characterization was performed through the interpretation of elastic attributes extracted from 3D reflection seismic data inversion and AVO (amplitude versus offset) analysis. The results regarded as the best ones were obtained from the ratio between Lame’s coefficients, λ/µ (for the former) and an AVO attribute related to the so-called parameter “B” from Aki-Richards equation (Aki and Richards, 1980) for the latter. Although seismic inversion is more commonly applied to relatively consolidated rocks in the hydrocarbon Exploration, we were able to discriminate less consolidated sediments from the near seabed section in terms of four different morphostructural domains or compartments as well as a few faciological characteristics. In addition to the conventional seismic data, high resolution data (sub-bottom profile or SBP and multi-beam bathymetry) were used. Other sources of information include geotechnical in situ data (soil resistance to the penetration of piezocone device or PCPT and seismic piezocone device or SPCPT) and geological sampling through piston core.