According to one embodiment, a system for accessing a subterranean zone from the surface includes a well bore extending from the surface to the subterranean zone, and a well bore pattern connected to the junction and operable to drain fluid from a region of the subterranean zone to the junction.

A method of sealing and pressurizing underground facilities in planetary bodies with atmospheric pressures or temperatures differing from that of earth may include disposing at least one prefabricated, airtight plug within the tunnel system prior to forming additional tunnels or shafts within the tunnel system. Multiple plugs may be additionally disposed within the tunnel system to create various encapsulated tunnel portions optionally having differing pressures and temperatures. The tunnel system may be airtight and sealed from external, hostile atmospheric conditions, designed to facilitate safe living and work conditions in the tunnel systems and to facilitate safe movement of people and equipment between tunnels, shafts and the surface of the planetary body. Tunnel systems are defined as any variety of man-made mines and tunnels or naturally occurring tunnels such as lava tubes or caverns and the like.

A method of sealing and pressurizing underground facilities in planetary bodies with atmospheric pressures or temperatures differing from that of earth may include disposing at least one prefabricated, airtight plug within the tunnel system prior to forming additional tunnels or shafts within the tunnel system. Multiple plugs may be additionally disposed within the tunnel system to create various encapsulated tunnel portions optionally having differing pressures and temperatures. The tunnel system may be airtight and sealed from external, hostile atmospheric conditions, designed to facilitate safe living and work conditions in the tunnel systems and to facilitate safe movement of people and equipment between tunnels, shafts and the surface of the planetary body. Tunnel systems are defined as any variety of man-made mines and tunnels or naturally occurring tunnels such as lava tubes or caverns and the like.

A high-efficiency permeability enhancement device for coal-seam gas drainage, wherein, including: a high-pressure gas cylinder, an air compressor being connected to a gas outlet of the high-pressure gas cylinder, a drill pipe, a plurality of jet nozzles being evenly disposed in a circumferential direction of the drill pipe, located below a drill bit, arranged outwards along a radial direction of the drill pipe, and in communication with the gas outlet of the high-pressure gas cylinder; and a plurality of self-driving drill bits being evenly disposed in the circumferential direction of the drill pipe, and located below the jet nozzles, wherein an end of the drill pipe is provided with the drill bit, a front end of the self-driving drill bits is radially defined with a plurality of front spray holes, and the self-driving drill bits are in communication with the gas outlet of the high-pressure gas cylinder.

A high-efficiency permeability enhancement device for coal-seam gas drainage, wherein, including: a high-pressure gas cylinder, an air compressor being connected to a gas outlet of the high-pressure gas cylinder, a drill pipe, a plurality of jet nozzles being evenly disposed in a circumferential direction of the drill pipe, located below a drill bit, arranged outwards along a radial direction of the drill pipe, and in communication with the gas outlet of the high-pressure gas cylinder; and a plurality of self-driving drill bits being evenly disposed in the circumferential direction of the drill pipe, and located below the jet nozzles, wherein an end of the drill pipe is provided with the drill bit, a front end of the self-driving drill bits is radially defined with a plurality of front spray holes, and the self-driving drill bits are in communication with the gas outlet of the high-pressure gas cylinder.

The present invention provides a method for coal seam gas seepage displacement, seepage water locking and dust reduction. During the injection period, a pressure pump and pumping system are used to control the pressure and pumping flow rate, and a micro-nano bubble surface active liquid coupling medium is used for seepage displacement of coal seam gas, ensuring efficient discharge or extraction of coal seam gas. After the injection is completed, the micro-nano bubbles surface-active liquid coupling medium is stored in the coal seam, and the coal seam is subjected to seepage water locking and dust reduction. Through the seepage displacement, the seepage velocity of coal seam gas is increased. Through the seepage water locks, the desorption rate of coal seam gas is suppressed. Through the dust reduction, the wetting reversal of coal seams can be achieved, and the moisture content is increased, thereby reducing the generation of dust.

The present invention provides a method for coal seam gas seepage displacement, seepage water locking and dust reduction. During the injection period, a pressure pump and pumping system are used to control the pressure and pumping flow rate, and a micro-nano bubble surface active liquid coupling medium is used for seepage displacement of coal seam gas, ensuring efficient discharge or extraction of coal seam gas. After the injection is completed, the micro-nano bubbles surface-active liquid coupling medium is stored in the coal seam, and the coal seam is subjected to seepage water locking and dust reduction. Through the seepage displacement, the seepage velocity of coal seam gas is increased. Through the seepage water locks, the desorption rate of coal seam gas is suppressed. Through the dust reduction, the wetting reversal of coal seams can be achieved, and the moisture content is increased, thereby reducing the generation of dust.