Method and apparatus for using pressure cycling and cold liquid CO2 for releasing natural gas from coal and shale formations
US9453399B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Aug 13, 2014 |
| Grant date | Sep 27, 2016 |
| Priority date | — |
| Expiry date | Jan 13, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P90/70
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and apparatus for sequestering carbon dioxide (CO2) gas and releasing natural gas from underground coal and/or gas shale formations using CO2 gas captured from the flue gas of a coal burning power plant, and processing it to produce cold liquid pressurized CO2, and injecting the cold liquid CO2 under pressure to create fractures within the formation and causing the CO2 to be adsorbed into the coal or gas shale and natural gas (CH4) to be desorbed, released and recovered. A special pressure cycling process is used to enable the pressure within the formation to be increased and decreased, including allowing the liquid CO2 to change phase to a gaseous CO2, and injecting the liquid CO2 under pressure repeatedly, which causes greater expansion of the proliferation zone within the formation, and more efficiently releases CH4.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.