About the first author HUANG Leqing,born in 1985,senior engineer,is engaged in research on the Cretaceous aeolian deposits and aquifer energy storage. E-mail: 289773254@qq.com.
To investigate the feasibility of compressed carbon dioxide(CO2)energy storage in deep aquifers of the Hengyang Basin,this study focuses on the Honghuatao Formation sandstone reservoir within the Cretaceous paleo-desert aeolian sedimentary strata. By integrating petrological characterization experiments with site-scale numerical simulations,the carbon sequestration and energy storage potential of the reservoir were systematically evaluated. Petrographic thin-section analysis,scanning electron microscopy(SEM),and porosity-permeability tests reveal that the Honghuatao Formation sandstone is predominantly composed of medium-to fine-grained feldspathic quartz sandstone with pervasive calcareous cementation. The reservoir exhibits low porosity and permeability,characteristic of tight sandstone. The overlying mudstone caprock,with negligible porosity and stable regional distribution,forms an effective reservoir-seal combination.A three-dimensional numerical model of the compressed CO2 energy storage system was established based on experimental data. Simulation results indicate that under a reservoir permeability of 15×10-3 μm-2,60-day cyclic injection-withdrawal operations induce pressure fluctuations≤0.5 MPa,with energy round-trip efficiency exceeding 99.98%. Additionally,low-temperature CO2 injection triggers localized temperature reduction(up to 5 ℃),pore pressure accumulation(maximum 1.27 MPa),partial effective stress reduction,and significant vertical displacement in the reservoir. The study demonstrates that the Honghuatao Formation sandstone holds potential for CO2 storage and energy storage. However,its low permeability limits injection-withdrawal capacity,necessitating acidification or hydraulic fracturing modifications to enhance pore-permeability properties for scalable applications. This research provides theoretical insights into the utilization of paleo-desert aeolian sandstone for subsurface energy storage and the advancement of low-carbon energy technologies.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |