BATISTA, J. T; http://lattes.cnpq.br/7812413413221928; BATISTA, Juliana Targino.
Resumo:
The physical properties most used in the prospecting and management of
hydrocarbon reservoirs are elastic and electrical properties. In order to understand
how these properties are affected by pore types and their interconnectivity, this
research aims to simulate, using the finite element method, these properties in digital
rock models obtained by X-ray microtomography. The simulation results are analyzed
using the statistical method of piecewise linear regression. Electrical simulations
demonstrated how the porosity of macropores and micropores, as well as their
interconnectivities, influence the electrical properties of carbonate and sandy rocks,
and consequently, the exponents m and n of the Archie equation. Generally, the
cementation exponent (m) is directly proportional to the volumetric fraction of
microporous phases and inversely proportional to the connectivity of macropores.
The results indicate that there is a direct relationship between the saturation
exponent (n) and the interconnectivity of the microporous phase, but an ambiguous
relationship with the porosity of macropores, their interconnectivity, and the
volumetric fraction of the microporous phase. Simulated elastodynamic properties
show an inverse relationship with the volumetric fraction of the microporous phase
and the porosity of macropores. The variable with the greatest influence on static
moduli is the volumetric fraction of the microporous phase. Finally, numerically
simulated elastodynamic moduli exhibit higher values than their corresponding static
values, as reported in the literature for conventional experiments. The method
developed in this research can be applied to other types of rocks, and analysis of
how pore types and their topologies affect the petrophysical properties of carbonate
and siliciclastic rocks offers a novel approach for the exploitation of underground
natural resources by society, with greater efficiency and lower environmental cost.