A hydrate solid-state fluidization mining method and system under an underbalanced reverse circulation condition are used for solid-state fluidization mining on a non-rock-forming weak-cementation natural gas hydrate layer in the ocean. Equipment includes a ground equipment system and an underwater equipment system. The construction procedure includes an earlier-stage construction process, pilot hole drilling construction process, reverse circulation jet fragmentation process, underbalanced reverse circulation fragment recovery process and silt backfilling process. Natural gas hydrates in the seafloor are mined through an underbalanced reverse circulation method. Problems such as shaft safety, production control and environmental risks faced by conventional natural gas hydrate mining methods such as depressurization, heat injection, agent injection and replacement are effectively solved. By using the method, the weak-cementation non-rock-forming natural gas hydrates in the seafloor can be mined in environment-friendly, efficient, safe and economical modes, more energy resources can be provided, and energy shortage dilemmas are solved.

A method of extracting gas from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity is provided. A horizontal well drilling and reaming subsystem constructs a U-shaped well in which a horizontal well adjoins a vertical well, and performs a reaming process on a horizontal section of the horizontal well to enlarge a hole diameter. A horizontal well hole-collapse cavity-construction depressurization excitation subsystem performs pressure-pulse excitation and stress release on the horizontal well of tectonically-deformed coal bed methane, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section along a depressurizing space. A product lifting subsystem pulverizes the coal and lifts the mixture towards a wellhead of a vertical well. A gas-liquid-solid separation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation conditions and the execution processes of technical equipment in real time.

A method of extracting gas from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity is provided. A horizontal well drilling and reaming subsystem constructs a U-shaped well in which a horizontal well adjoins a vertical well, and performs a reaming process on a horizontal section of the horizontal well to enlarge a hole diameter. A horizontal well hole-collapse cavity-construction depressurization excitation subsystem performs pressure-pulse excitation and stress release on the horizontal well of tectonically-deformed coal bed methane, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section along a depressurizing space. A product lifting subsystem pulverizes the coal and lifts the mixture towards a wellhead of a vertical well. A gas-liquid-solid separation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation conditions and the execution processes of technical equipment in real time.

Disclosed is a device for solid-state fluidized mining of natural gas hydrates in a shallow seabed, including: a sea surface support system, a pipeline delivery system, and an undersea drilling system. The sea surface support system includes a hydrate drilling vessel floating on seawater. The pipeline delivery system includes a continuous double-layer oil pipe, a recyclable conduit installed in a sediment cover, an open-hole steering packer installed outside the recyclable conduit. The undersea drilling system includes a hydrate slurry separator, a single screw pump, a hydraulic motor, a jet head and a differential pressure sliding sleeve close to the hydrate drill bit. The present invention has the following beneficial effects. The device achieves a multi-directionally horizontal drilling and production in the hydrate reservoir with a single well head, improving the drilling efficiency and single well production.

A method of extracting gas from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity is provided. A horizontal well drilling and reaming subsystem constructs a U-shaped well in which a horizontal well adjoins a vertical well, and performs a reaming process on a horizontal section of the horizontal well to enlarge a hole diameter. A horizontal well hole-collapse cavity-construction depressurization excitation subsystem performs pressure-pulse excitation and stress release on the horizontal well of tectonically-deformed coal bed methane, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section along a depressurizing space. A product lifting subsystem pulverizes the coal and lifts the mixture towards a wellhead of a vertical well. A gas-liquid-solid separation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation conditions and the execution processes of technical equipment in real time.

A method of extracting gas from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity is provided. A horizontal well drilling and reaming subsystem constructs a U-shaped well in which a horizontal well adjoins a vertical well, and performs a reaming process on a horizontal section of the horizontal well to enlarge a hole diameter. A horizontal well hole-collapse cavity-construction depressurization excitation subsystem performs pressure-pulse excitation and stress release on the horizontal well of tectonically-deformed coal bed methane, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section along a depressurizing space. A product lifting subsystem pulverizes the coal and lifts the mixture towards a wellhead of a vertical well. A gas-liquid-solid separation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation conditions and the execution processes of technical equipment in real time.

A controller for controlling a slurry flowing from incoming piping and entering hydrocyclones arranged in a battery configuration, featuring a signal processor that receives signaling containing information about respective individual cyclone control signaling x(i) for each individual cyclone being evaluated and controlled, median control signaling {tilde over (x)} of all of the respective individual cyclone control signaling x(i), a scale factor A.sub.i and a number N of the individual cyclones being evaluated and controlled; and determine/provides primary control signaling C containing information to control the slurry flowing from the incoming piping and entering the hydrocyclones arranged in the battery configuration by taking the median control signaling {tilde over (x)} and adding a correction factor, where the correction factor is determined by taking a sum of a respective difference of each of the respective individual cyclone control signaling x(i) and the median control signaling {tilde over (x)}, applying the scaling factor A.sub.i to each respective difference, and normalizing the sum by the number N of the individual cyclones being evaluated and controlled, based upon the signaling received.

A controller for controlling a slurry flowing from incoming piping and entering hydrocyclones arranged in a battery configuration, featuring a signal processor that receives signaling containing information about respective individual cyclone control signaling x(i) for each individual cyclone being evaluated and controlled, median control signaling {tilde over (x)} of all of the respective individual cyclone control signaling x(i), a scale factor A.sub.i and a number N of the individual cyclones being evaluated and controlled; and determine/provides primary control signaling C containing information to control the slurry flowing from the incoming piping and entering the hydrocyclones arranged in the battery configuration by taking the median control signaling {tilde over (x)} and adding a correction factor, where the correction factor is determined by taking a sum of a respective difference of each of the respective individual cyclone control signaling x(i) and the median control signaling {tilde over (x)}, applying the scaling factor A.sub.i to each respective difference, and normalizing the sum by the number N of the individual cyclones being evaluated and controlled, based upon the signaling received.

A method of drilling vertical and horizontal pathways to mine for solid natural resources involves a drill bit, at least one reamer, a first plugging material, and a second plugging material; drilling a testing wellbore to a specific vertical depth with the drill bit and identifying at least one desired mining section wherein the desired mining section is associated with a corresponding vertical depth; creating a new bottom end for the testing wellbore by filling the testing wellbore up to an offset distance with the first plugging material; drilling a horizontal access hole from the new bottom end into the desired mining section with the drill bit and enlarging it with a reamer; excavating cuttings from the desired mining section through the horizontal access hole; filling the horizontal access hole with the second plugging material; and repeating the drilling, enlarging, and filling process to create a plurality of lateral holes.

A hydrate solid-state fluidization mining method and system under an underbalanced reverse circulation condition are used for solid-state fluidization mining on a non-rock-forming weak-cementation natural gas hydrate layer in the ocean. Equipment includes a ground equipment system and an underwater equipment system. The construction procedure includes an earlier-stage construction process, pilot hole drilling construction process, reverse circulation jet fragmentation process, underbalanced reverse circulation fragment recovery process and silt backfilling process. Natural gas hydrates in the seafloor are mined through an underbalanced reverse circulation method. Problems such as shaft safety, production control and environmental risks faced by conventional natural gas hydrate mining methods such as depressurization, heat injection, agent injection and replacement are effectively solved. By using the method, the weak-cementation non-rock-forming natural gas hydrates in the seafloor can be mined in environment-friendly, efficient, safe and economical modes, more energy resources can be provided, and energy shortage dilemmas are solved.