Shale heterogeneity is important for micro- to macroscale-quality reservoir prediction. We evaluated the multiscale heterogeneity in shale based on thin-section observation, field emission scanning electron microscope observation, low-pressure [Formula: see text] adsorption analysis, mercury intrusion porosimetry, organic carbon analysis, and bulk chemical analysis by X-ray powder diffraction. We evaluated the results in which the heterogeneity of minerals and organic matter in shale was shown by disorderly and unsystematically distributed mineral grains, lamina, and rapid lithology at multiple scales. The random arrangement of minerals, seasonal climate changes, large changes of sedimentary environment, and the provenance supply was considered to be the origin of the heterogeneity from the micro- to the macroscale in shale. In addition, a multiscale heterogeneity distribution model of marine shale in southeastern Sichuan basin was established, which can be used to predict shale gas distribution from the micro- to the macroscale.
The pore structure of sandstone in an oil reservoir is investigated using atomic force microscopy (AFM). At nanoscale resolution, AFM images of sandstone show us the fine structure. The real height data of images display the three-dimensional space structure of sandstone effectively. The three-dimensional analysis results show that the AFM images of sandstone have unique characteristics that, like fingerprints, can identify different structural properties of sandstones. The results demonstrate that AFM is an effective method used to represent original sandstone in petroleum reservoirs, and may help geologists to appreciate the sandstone in oil reservoirs fully.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.