Patent ID: 8833474
Filing Date: 2014-09-16
Classification: E21B,Y02C,Y02P

Abstract:
1. A method of sequestering carbon dioxide and recovering natural gas from a coal or gas shale reservoir, comprising: capturing or producing carbon dioxide gas from coal or from flue gases of a power plant, incinerator or chemical processing plant; cooling the carbon dioxide gas to create liquid carbon dioxide; injecting the liquid carbon dioxide into an injection pipe extended into said reservoir, wherein said injection pipe has perforations that allow the carbon dioxide to be released into said reservoir, using the following steps: 1) introducing liquid nitrogen into said injection pipe to pre-chill said pipe; 2) introducing said liquid carbon dioxide into said injection pipe gradually with a top vent of said injection pipe open and a bottom valve of said injection pipe closed; 3) turning on a pump to pressurize said liquid carbon dioxide; 4) closing said top vent of said injection pipe and injecting said pressurized liquid carbon dioxide into said injection pipe until the pressure within said injection pipe reaches a predetermined amount which is above the fracture strength of said coal or shale in said reservoir; 5) opening said bottom valve of said injection pipe and allowing said liquid carbon dioxide to be released under pressure through said perforations and into said coal or shale reservoir and causing the coal or shale in said reservoir to break up; 6) closing said bottom valve and allowing said liquid carbon dioxide in said reservoir to change phase into a gaseous carbon dioxide; 7) allowing the gaseous carbon dioxide to adsorb onto the coal or shale and allowing natural gas to be desorbed and released from the coal or shale; 8) recovering the natural gas released from the coal or shale through one or more recovery pipes; and 9) repeating steps 2) through 8).