Characterization and microfabrication of natural porous rocks: from micro-CT imaging and digital rock modelling to micro-3D-printed rock analogs

Embargo End Date
2023-04-01

Type
Article

Authors
Song, Rui
Wang, Yao
Sun, Shuyu
Liu, Jianjun

KAUST Department
Computational Transport Phenomena Lab
Earth Science and Engineering Program
Physical Science and Engineering (PSE) Division

KAUST Grant Number
BAS/1/1351-1301

Online Publication Date
2021-04-18

Print Publication Date
2021-10

Date
2021-04-18

Submitted Date
2021-01-11

Abstract
Tests on standard rock specimens with controlled and identical pore structure are critical to validating the analytical and numerical models. However, it is usually difficult to acquire two natural samples with the same internal structure for the destructive laboratory tests, for the sake of the heterogeneity of natural rock which is caused by the complex diagenetic processes. Three-dimensional (3D) printing technology provides an alternative approach to produce geometry-identical, features-controllable, and lab-testable analogs of natural rock from digital data in a faster and more cost-effective way. This paper presents a customized workflow of 3D-printed rock analogs from micro-CT images combining with digital rock modelling. Three types of natural rock specimens are imaged by micro-CT and processed as inputs for two types of 3D printing techniques. Rock analogs are printed at multiple magnifications from original CT volume in five curable resin materials. Petrophysical parameters of 3D-printed rock analogs are acquired through helium pycnometry (HP) and mercury intrusion porosimetry (MIP). The accuracy of 3D-printed rock analogs is evaluated by comparing the measured results with the benchmark data derived from the digital rock modelling. Both the advantages and the current challenges to reproduce the real pore structure of natural rock by the 3D-printed analogs are discussed. The results indicate that the gypsum-based printed analogs are prior to modelling the surface roughness and wettability properties to natural rock grains, while the resin-based printed analogs owe advantages on reproducing pore structure. As the first effort in literature, this study investigates the inherent relationship between digital rock and 3D-printed rock analogs via comprehensive comparison on petrophysical properties. The results approve that the 3D printing technique is a novel, feasible, and alternative approach for laboratory test to generate rock analogs from the digital model of the natural rock. However, it is still difficult to print the pore structure of the rock at the original dimension.

Citation
Song, R., Wang, Y., Sun, S., & Liu, J. (2021). Characterization and microfabrication of natural porous rocks: from micro-CT imaging and digital rock modelling to micro-3D-printed rock analogs. Journal of Petroleum Science and Engineering, 108827. doi:10.1016/j.petrol.2021.108827

Acknowledgements
This paper is financially supported by National Natural Science Foundation of China (Grant No. 51909225); Natural Science Foundation of SWUST (Grant No. 20zx7129); King Abdullah University of Science and Technology (KAUST) (Grant Number BAS/1/1351-1301); and financial support from China Scholarship Council.

Publisher
Elsevier BV

Journal
Journal of Petroleum Science and Engineering

DOI
10.1016/j.petrol.2021.108827

Additional Links
https://linkinghub.elsevier.com/retrieve/pii/S0920410521004885

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