Investigation into Enhancing Methane Recovery and Sequestration Mechanism in Deep Coal Seams by CO<sub>2</sub> Injection
Injecting CO<sub>2</sub> into coal seams to enhance coal bed methane (ECBM) recovery has been identified as a viable method for increasing methane extraction. This process also has significant potential for sequestering large volumes of CO<sub>2</sub>, thereby reducing the co...
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-11-01
|
| Series: | Energies |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1073/17/22/5659 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Injecting CO<sub>2</sub> into coal seams to enhance coal bed methane (ECBM) recovery has been identified as a viable method for increasing methane extraction. This process also has significant potential for sequestering large volumes of CO<sub>2</sub>, thereby reducing the concentration of greenhouse gases in the atmosphere. However, for deep coal seams where formation pressure is relatively high, there is limited research on CO<sub>2</sub> injection into systems with higher methane adsorption equilibrium pressure. Existing studies, mostly confined to the low-pressure stage, fail to effectively reveal the impact of factors such as temperature, high-pressure CO<sub>2</sub> injection, and coal types on enhancing the recovery and sequestration of CO<sub>2</sub>-displaced methane. Thus, this study aims to investigate the influence of temperature, pressure, and coal types on ECBM recovery and CO<sub>2</sub> sequestration in deep coal seams. A series of CO<sub>2</sub> core flooding tests were conducted on various coal cores, with CO<sub>2</sub> injection pressures ranging from 8 to 18 MPa. The CO<sub>2</sub> and methane adsorption rates, as well as methane displacement efficiency, were calculated and recorded to facilitate result interpretation. Based on the results of these physical experiments, numerical simulation was conducted to study multi-component competitive adsorption, desorption, and seepage flow under high temperature and high pressure in a deep coal seam’s horizontal well. Finally, the optimization of the total injection amount (0.7 PV) and injection pressure (approximately 15.0 MPa) was carried out for the plan of CO<sub>2</sub> displacement of methane in a single well in the later stage. |
|---|---|
| ISSN: | 1996-1073 |