Author Identifier (ORCID)
Abstract
The efficiency of CO2 geo-sequestration relies heavily on the storage capacity and sealing integrity of the heterogeneous strata. Tight formations offer substantial advantages for long-term CO2 geological storage, however, the stratigraphic variability and lithological heterogeneity introduce substantial uncertainty in real-world engineering applications. Particularly, for tight formations with pronounced heterogeneous lithologies, traditional methods oversimplify their impact on CO2 geo-sequestration. To address this challenge and identify the most effective intervals for CO2 geo-sequestration, we investigated the middle Permian Lucaogou Formation (P2l) in the Jimusar Sag, Junggar Basin, Northwest China, a region known for its strong lithological heterogeneity. By integrating multi-scale analytical techniques, including X-ray diffraction, permeability and porosimetry, mercury injection capillary pressure, petrography analysis, and nanoindentation, more than 100 consecutive core samples from Borehole J174, covering the stratigraphic interval of 250 m, were analyzed. Our results reveal significant heterogeneity and identify the most favorable intervals for CO2 geo-sequestration located in the upper P2l12 and lower P2l11 units (3238–3334 m depth), spanning 96 m. It primarily consists of tuffaceous siltstone, siltstone, interbedded multi-layered dolomitic siltstone and silty dolostone, which exhibit excellent petrophysical properties with high storage capacity and mechanical stability. Above the storage interval, an effective caprock is found in the lower P2l22 and P2l11 group (3149–3238 m depth, spanning 89 m), characterized by thick mudstone with extremely low porosity, permeability, and appropriate mechanical properties, ensuring long-term sealing integrity. This study provides precise identification for CO2 geo-sequestration in engineering practice and also demonstrates a scalable methodology to tackle upscaling challenges in heterogeneous formations, providing valuable implications for future CO2 geo-sequestration projects in similar engineering settings.
Keywords
CO2 geo-sequestration, Heterogeneity, Sealing integrity, Storage capacity
Document Type
Journal Article
Date of Publication
7-1-2026
Article Number
207713
Volume
189
Publication Title
Marine Geoscience and Energy Resources
Publisher
Elsevier
School
School of Engineering
RAS ID
99409
Funding Information
We acknowledge that part of the research's experiments were funded by National Natural Science Foundation of China (42302162). Z. Y. acknowledges the support of the National Overseas Top Talents Program of China (JXRSB02001) and the Natural Science Foundation of Xinjiang, China (2025D01A153).
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Yuan, Y., Cao, Y., Al-Khdheeawi, E. A., Lebedev, M., You, Z., Rezaee, R., Iglauer, S., Zhang, L., & Feng, Z. (2026). Optimal CO2 storage interval in heterogeneous tight formation: Implications for long-term carbon sequestration. Marine Geoscience and Energy Resources, 189, Article 207713. https://doi.org/10.1016/j.marger.2026.207713