OLIVEIRA, L. S. B.; http://lattes.cnpq.br/4041246284452547; OLIVEIRA, Lorenna Sávilla Brito.
Resumo:
The deformation bands change physics properties and mechanical of the rocks, influencing the flow on the porous rocks. These structures are principally in porous sandstones and usually are associated with a distensive setting. Moreover, deformation
bands are research targets related to quantification and transformation of petrophysics
properties and rheologic of the rocks from a reservoir. In this context, this study seeks to
analyze the deformation bands and their influence in porous sandstones at the Rio do
Peixe basin. This study addresses the following issues: (i) what is the deformation bands
behavior in different layers of sandstones; (II) what is the mechanical resistance of the
sedimentary units shows in the propagation of brittle deformation. To that, the structural
data, mechanical stratigraphic and geomechanics were taken in the field with the aim to
realize a digital geologic model. During the mechanic structural characterization in a
scanline, uniaxial mechanical analyzes were realized using Schmidt hammer at the areas
with and without deformation. The results indicate that stratigraphic units with higher
granulometry allow smaller deformation bands inflection as higher thickness of these.
Similarly, the stratigraphic units with smaller granulometry allow higher frequency of the
deformation bands. Besides that, deformed areas showed higher values of uniaxial
compressive strength when compared to units with smaller granulometry that have
smaller uniaxial compressive strength. The mechanic stratigraphic control has the
thickness of the layer as a differential parameter when affected by deformation, where
layers with higher thickness have higher resistance from the deformation concerning to
frequency and inflexion. The 3D geologic model provides the cave shape visualization,
stratigraphic units and their limits, besides penetrability, spacing and geometry of the
structures. The adaptation of the mechanical stratigraphic technique for deformation
bands used the petrophysical parameters, UCS and frequency of these structures to define the mechanical unit. Although of being the same lithostratigraphic unit, the granulometric differences and of structure provided different mechanic resistances to the layers, precluding the propagation of deformation bands for these distinctions.