The disclosure provides a multi-type hydrate formation simulation system and a method thereof. The simulation system comprises a hydrate generator, a gas source device and a cryogenic cooler. The hydrate generator comprises a reactor, in which a formation simulation space is provided and can be selectively filled with a loose formation skeleton or a consolidated formation skeleton. The gas source device is configured to introduce natural gas at a preset pressure into the formation simulation space. The cryogenic cooler comprises a temperature-adjustable thermotank, in which the hydrate generator is arranged. The simulation system and method provided can be used to study the influence of consolidated hydrate formation structures and loose hydrate formation structures and particle contact modes on the physical properties of hydrate rock, and are of great significance to the interpretation of hydrate formation exploration data and the estimation of hydrate saturation.

The disclosure discloses a solid fluidization tubular separator for marine natural gas hydrate, which includes a first separator and a second separator, wherein the first separator includes the first separation sleeve, the power liquid pipe, the swirl baffle, the recovery mechanism and the sand discharge mechanism. After the hydrate is sucked into the first separation sleeve to generate a circumferential velocity, so that the mud and sand with high density are separated to the pipe wall of the first separation sleeve, and the mud and sand separated to the pipe wall are settled down from the gap between the swirl baffle and the pipe wall along the pipe wall. The hydrate swirl flows into the recovery mechanism, and then leaves the first separation sleeve and enters the second separator, so as to realize the separation of mud and sand and natural gas hydrate.

The invention provides a self drilling side pressure simulation test device and method for a formation containing natural gas hydrate, belonging to the technical field of geotechnical mechanics. The device comprises a reactor, a cutting tool, a mud conveying mechanism and a side pressure testing device. The reactor is used to fill the simulated substance of the formation containing natural gas hydrate to be tested. The cutting tool is arranged in the reactor, and the cutting tool can move up and down relative to the reactor. One end of the mud conveying mechanism is connected with the reactor, for outputting the mud cut by the cutting tool from the reactor; The side pressure test device can complete the side pressure test experiment with the cutting tool moving to the set depth. The method is implemented based on the device. The in-situ test method can directly test the engineering mechanical parameters of the formation containing natural gas hydrate. At the same time, it is of great significance to the formation stability of natural gas hydrate development and the prevention and control of engineering disasters.

An application method of a device for accurately evaluating the vertical content distribution of an undersea hydrate reservoir includes the following steps: assembling the device into a whole and screwing it into an undersea well; activating natural gas hydrates to produce gaseous substances; opening a directional guide channel corresponding to a thermal excitation system in a working state in S2, so that gaseous natural gas hydrates generated in this horizon enter a screw-in long sleeve through the directional guide channel; collecting, by a gas collection system, the gaseous natural gas hydrates; analyzing and recording components and contents in a box by an optical ranging unit and a resistivity unit; repeating S4 and S5 till the end of one collection cycle; and performing data processing and analysis. In this way, accurate evaluation of the vertical content distribution of undersea hydrates is realized.

A device for measuring stratum deformation caused by natural gas hydrate dissociation is provided. The device is configured to be disposed inside a natural gas hydrate reactor, wherein the natural gas hydrate reactor is configured to simulate natural gas hydrate formation layers in the natural gas hydrate reactor, and the natural gas hydrate formation layers include a superstratum layer, a sediment layer and a substratum layer from top to bottom. The device includes a displacement sensor fixing plate, displacement sensors and a flexible elastic plate. A plurality of displacement sensors are provided and evenly distributed, wherein a first end of each displacement sensor is fixed to the displacement sensor fixing plate and a second end of each displacement sensor is stretchably and sealingly fixed to the flexible elastic plate. The flexible elastic plate is tightly attached to the superstratum layer.

A magnetofluid enhanced electromagnetic heating device and method for preventing and treating secondary hydrates around a well are provided. When exploiting natural gas hydrates by depressurization, secondary hydrates or ice can form due to the decreasing temperature around the well, so that gas migration in sediment is blocked, and the gas production is reduced. According to this disclosure, a coil is arranged outside a casing pipe to generate an alternating electromagnetic field radiated to sediment. As a result, magnetite nanoparticles naturally contained in the sediment generate magnetothermal effect to heat the sediment. Additionally, the magnetofluid containing the ferromagnetic nanoparticles can be injected together with fracturing fluid during hydraulic fracturing of the reservoir, so that the magnetothermal effect of the sediment is further enhanced. Thus, secondary hydrates or ice can be prevented from forming around the well so that the exploitation efficiency of natural gas hydrates is improved.

A device and a method for physical characterization in a large-scale natural gas hydrate experimental system are provided. The device includes a reactor, horizontal wellbores, and vertical wellbores. The reactor includes an upper cover, a lower cover, and a reactor body, and the upper cover and the lower cover are sealably attached to two ends of the reactor to form a closed chamber. The physical characterization device further includes lateral vertical well assemblies and temperature-pressure-resistance assemblies, wherein the lateral vertical well assemblies and the temperature-pressure-resistance assemblies are disposed to penetrate the reactor from the upper cover to the lower cover. The physical characterization method is conducted using the physical characterization device, including a step of producing contour plots using a data processing software with three-dimensional matrix data collected by the pressure measuring tubes, the temperature measuring tubes, and the resistivity measuring columns.

A cavity creation tool by crushing with multi-stage controllable water jet, it is used in natural gas hydrate development and mainly consists of an inner tube upper joint, an inner tube lower joint, an intermediate sleeve, an inner structure consisting of a coaxial throttle push rod, an outer layer sleeve, an outer layer structure consisting of a supporting ring, a jet head mounted to the intermediate sleeve and threading the outer layer sleeve, and a jet crushing structure consisting of a single-stage telescopic jet head and a two-stage telescopic jet head.

A device and a method for experimental exploitation of natural gas hydrates in full-sized production wells are provided. The device includes a full-diameter well, and the full-diameter well includes a heating circulation tube, a temperature sensor tube, an upper sealing unit and a lower sealing unit. Perforations are provided along a body of the full-diameter well. A reactor includes an upper cover, a lower cover, and a reactor body. The method is conducted by using the device and the reactor. The device and method allow simulation of sand-control wellbores in actual exploitation of natural gas hydrates, and realize horizontal and vertical sand-control experiments.

A device and a method for gas-water-sand separation and measurement during a simulated exploitation of natural gas hydrates are disclosed. The device includes a natural gas hydrate formation and dissociation system and a filtering unit. The natural gas hydrate formation and dissociation system includes a compressed air pump, a reactor, and a water-bath temperature regulating unit. The filtering unit includes a kettle body, wherein an inlet end of the kettle body is connected to the sand-control liner zone, an outlet end of the kettle body is connected to a water-collecting container, and a plurality of filtering layers are disposed inside the kettle body from the inlet end to the outlet end. The method is conducted using the device. The device and the method realize the gas-water-sand separation and measurement of produced gas-water-sand mixture during a simulative exploitation process, allowing for a direct inspection on a sand production and sand control.