Permeability Characterization of Natural Compaction Bands Using Core Flooding Experiments and 3-D Image-Based Analysis: Comparing and Contrasting the Results From Two Different Methods
We measured the permeabilities of six sets of compaction bands and the adjacent host rocks of aeolian Aztec Sandstone using core flooding experiments. The results show that the permeability within the three sets of high-angle compaction bands is consistently three orders of magnitudes lower than that of the host rocks. For the bed-parallel compaction bands, the measured permeability reduction is about one to three orders of magnitudes within the bands, except that there is no detected permeability reduction within one set of the samples of the bed-parallel compaction bands. For the samples that show permeability reduction within high-angle and bed-parallel compaction bands, the results are consistent with the data estimated from 2D segmented image analyses in previous studies. Permeabilities of the samples used in the laboratory experiments were also obtained based on 3D tomographic images scanned from micro-cores and lattice-Boltzmann flow simulations. In addition, Backscatter Electron Images (BEI) and Energy Dispersive Spectroscropy Images (EDSI) of thin-sections were used to extract the microstructural attributes of compaction bands and host rocks. For the samples in which no permeability reduction were detected using core flooding experiments, the image-based permeability inside the band is approximately half an order lower than that outside the band. Taking into account the heterogeneity and the difference in sample size between micro-cores and the core plugs, the results from 3D image-based analysis is roughly comparable to data measured from core flooding experiments. Given the fact that this is the first study on directly measuring the permeability of natural compaction bands publicly available, the results provide important constraints for the permeability reduction associated with compaction bands in the aeolian Aztec Sandstone.
AAPG Datapages/Search and Discovery Article #90189 © 2014 AAPG Annual Convention and Exhibition, Houston, Texas, USA, April 6–9, 2014