Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8915491 | Journal of Applied Geophysics | 2018 | 10 Pages |
Abstract
Pore-scale analysis of carbonate rock is of great relevance to the oil and gas industry owing to their vast application potentials. Although, efficient fluid flow at pore scale is often disrupted owing to the tight rock matrix and complex heterogeneity of limestone microstructures, factors such as porosity, permeability and effective stress greatly impact the rock microstructures; as such an understanding of the effect of these variables is vital for various natural and engineered processes. In this study, the Savonnières limestone as a carbonate mineral was evaluated at micro scales using X-ray micro-computed tomography at high resolutions (3.43â¯Î¼m and 1.25â¯Î¼mâ¯voxel size) under different effective stress (0â¯MPa, 20â¯MPa) to ascertain limestone microstructure and gas permeability and porosity effect. The waterflooding (5â¯wt% NaCl) test was conducted using microCT in-situ scanning and nanoindentation test was also performed to evaluate microscale geomechanical heterogeneity of the rock. The nanoindentation test results showed that the nano/micro scale geomechanical properties are quite heterogeneous where the indentation modulus for the weak consolidated area was as low as 1â¯GPa. We observed that the fluid flow easily broke some less-consolidated areas (low indentation modulus) area, coupled with increase in porosity; and consistent with fines/particles migration and re-sedimentation were identified, although the effective stress showed only a minor effect on the rock microstructure.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geophysics
Authors
Yihuai Zhang, Maxim Lebedev, Ahmed Al-Yaseri, Hongyan Yu, Lezorgia N. Nwidee, Mohammad Sarmadivaleh, Ahmed Barifcani, Stefan Iglauer,