Results and Discussion on Physical Property Calculation from Pore Microstructures of Carbonate Rocks

Abstract:

In this paper, we report results and discussion on the physical properties estimation of carbonate rocks using pore microstructures. We obtained high-resolution 3D microstructures with different porosity-types (inter-particle, vuggy/moldic, and fracture) from the X-ray microtomography technique. We calculated permeability, electrical conductivity, and P-wave velocity using the Lattice-Boltzmann method and finite element methods. We also applied the pore-scale simulation techniques to different sub-blocks from the original 3D pore geometry (2,000³ voxels) to determine the heterogeneity of pore geometry. For the inter-particle porosity-type, the calculated transport properties (permeability and electrical conductivity) show very similar trends to clastic sediments. These relations can be modeled by common empirical relations such as Kozeny-Carman relation for porosity-permeability or Archie’s equation for porosity-formation factor. For the vuggy or fracture porosity-type, it is difficult to determine any consistent relations; therefore we tried to build conceptual models with cracks or vugs to establish quantitative relations. On the other hand, P-wave velocity showed very little dependence on the porosity-types, due to high frame stiffness of carbonate rocks.

Acknowledgements: This research was supported by the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Trade, Industry and Energy of Korea (GP2012-029).