Abstract: A crushing system for large-size natural gas hydrate rock samples, which mainly includes a crushing and stirring control subsystem, crushing and stirring execution subsystem and hydrate preparation subsystem. Full automatic control to parameter acquisition and experimental process is achieved by utilizing modern automation technology, including the function of automatically crushing the large-size natural gas hydrate rock samples and also monitoring, collecting and storing the drilling pressure, the torque and the internal furnace pressure and temperature parameters during the crushing process in real time, to provide reliable guarantee for the follow-up researches on crushing mechanism, crushing efficiency, drilling parameter optimization, rock crushing ability evaluation of a crushing tool and the like of the large-size natural gas hydrate rock samples and necessary experimental verification means for optimization of on-site exploiting construction conditions of natural gas hydrate.

Abstract: A natural gas hydrate solid-state fluidization mining method and system under an underbalanced positive circulation condition, used for performing 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 has an earlier-stage construction process, underbalanced hydrate solid-state fluidization mining construction process and silt backfilling process. Natural gas hydrates in the seafloor are mined through an underbalanced positive circulation method.

Abstract: 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.

Abstract: A natural gas hydrate solid-state fluidization mining method and system under an underbalanced positive circulation condition, used for performing 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 has an earlier-stage construction process, underbalanced hydrate solid-state fluidization mining construction process and silt backfilling process. Natural gas hydrates in the seafloor are mined through an underbalanced positive circulation method, and 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.

Abstract: 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.

Abstract: A crushing system for large-size natural gas hydrate rock samples, which mainly includes a crushing and stirring control subsystem, crushing and stirring execution subsystem and hydrate preparation subsystem. Full automatic control to parameter acquisition and experimental process is achieved by utilizing modern automation technology, including the function of automatically crushing the large-size natural gas hydrate rock samples and also monitoring, collecting and storing the drilling pressure, the torque and the internal furnace pressure and temperature parameters during the crushing process in real time, to provide reliable guarantee for the follow-up researches on crushing mechanism, crushing efficiency, drilling parameter optimization, rock crushing ability evaluation of a crushing tool and the like of the large-size natural gas hydrate rock samples and necessary experimental verification means for optimization of on-site exploiting construction conditions of natural gas hydrate.

Abstract: A method for intelligently determining hydrate drilling and production risks based on fuzzy judgment.