Abstract: A method for improving gas storage capacity of a natural gas hydrate based on a crystal regulation and control principle is provided. A II structure was formed on the basis that a thermodynamic additive slightly soluble or insoluble in water was added to a hydrate generation system to compromise the hydrate generation conditions, and a crystal structure of the hydrate generated in the system was then regulated and controlled to be a I-type methane hydrate by controlling temperature and pressure. Therefore, the method for improving gas storage capacity of a natural gas hydrate is provided to creatively and fundamentally solve the problem of low gas storage capacity in the thermodynamic additive system.

Abstract: A reactor and method commonly applicable for high-pressure in-situ DSC and neutron tests of a gas hydrate relates to the field of characterization of physical and chemical properties of the gas hydrate. The reactor can not only carry out a high-pressure and low-temperature in-situ DSC test of the hydrate but also be suitable for a neutron diffraction test of the hydrate. The reactor can be adapted to an existing high-pressure and low-temperature in-situ DSC device without the need to re-develop a whole set of system, thus greatly reducing the replacement cost of the device. Owing to the sectional design, the flexibility and the applicability of the reactor can be ensured. Researchers can conveniently transport the hydrate in a pressure-maintaining manner. Even at a long distance, with the assistance of a liquid nitrogen tank or a vehicle-mounted refrigerator, it can be ensured that the hydrate may not be decomposed during transportation.

Abstract: A method for storing and transporting a hydrate with high natural gas storage capacity is provided. The method adopts a mode of generating the hydrate at a low temperature and storing the hydrate at a high temperature, and specifically includes: in a mode that a hydrate reaction tank is used as a transportation tank at the same time, introducing a mixed hydrate reaction liquid into the hydrate reaction tank matched with a transportation vehicle; introducing natural gas; enabling a hydrate generation reaction at a temperature of 273.65-283.15 K; in case of equilibrium of the reaction, heating to a temperature of less than or equal to 298.15 K for storage for long-distance transportation. By adopting the present method, the hydrate with high natural gas storage capacity can be synthesized within a relatively short period of time, and the hydrate can be safely, economically and efficiently transported to a destination.

Abstract: A method for regulating and controlling a generated crystal form of a natural gas hydrate is provided. A mixture composed of a salt substance, a surfactant, a water-soluble thermodynamic additive and water is introduced in a generation process of the natural gas hydrate. The salt substance and the surfactant also have a synergistic effect with a water-soluble thermodynamic accelerator. The addition of the salt substance and the surfactant can change a local solubility of the water-soluble thermodynamic additive in water, so that the regulating and controlling process of the hydrate crystal can be realized, thereby improving a hydrate gas storage capacity and solving the problem of low natural gas storage capacity in the generated natural gas hydrate in a water-soluble thermodynamic additive system.

Abstract: A production and transportation system for natural gas hydrates includes a gas storage reservoir, a plurality of hydrate storage and transportation tanks, a refrigerator, a pressure regulating valve, a liquid storage tank, a living quarter/surrounding user, a hydrate storage reservoir, a plurality of connecting pipes, a plurality of one-way gas valves, one-way liquid valves, and optional liquid pumps. The plurality of hydrate storage and transportation tanks are connected in parallel through the connecting pipes and then connected with an output end of the gas storage reservoir through the pressure regulating valve, the liquid storage tank is connected with the optional liquid pump and then sequentially connected with the plurality of hydrate storage and transportation tanks, and the plurality of hydrate storage and transportation tanks are connected in parallel and then connected with an input end of the living quarter/surrounding user through the optional liquid pump.

Abstract: The present invention discloses a POS high-accuracy positioning method under occlusion, comprising: integrating single-point positioning data and differential correction data for solution to acquire high-accuracy position information; implementing a buffer through an RAM of an FPGA to cache the collected position information and a sampling time; when a satellite signal loss is detected by a system, fetching five pieces of position information from the RAM at a time before the signal is lost and five pieces of position information at a time after the signal is reappeared, and filtering the information to obtain filtered data; constructing an equation by using the filtered data, and estimating a signal lost position. By triggering an occlusion algorithm through the FPGA, the present invention improves an ability of a POS system to work in areas with weak satellite signals and meanwhile reduces an operation time, thereby meeting practical needs.

Abstract: An exploiting method and device of marine facies natural gas hydrate. The exploiting method comprises the following steps: (1) after the construction of a vertical well, a fixed pipe is constructed, the exploiting well is set in the center of the fixed pipe, and the mixture is filled between the inner wall of the fixed pipe and the outer wall of the exploiting well; (2) the self-excited oscillating jet nozzle enters the exploiting well along the vertical well to the designated position through an orifice on the exploiting well and sprays the mixture, so that the mixture is broken evenly to form artificial fractures; (3) under the corresponding temperature, the hydrate decomposes to produce gas by depressurized exploiting; (4) the gas-liquid mixture exploited by the exploiting well is separated into liquid and gas in the gas-liquid separation device to collect liquid and gas.

Abstract: An exploiting method and device of marine facies natural gas hydrate. The exploiting method comprises the following steps: (1) after the construction of a vertical well, a fixed pipe is constructed, the exploiting well is set in the center of the fixed pipe, and the mixture is filled between the inner wall of the fixed pipe and the outer wall of the exploiting well; (2) the self-excited oscillating jet nozzle enters the exploiting well along the vertical well to the designated position through an orifice on the exploiting well and sprays the mixture, so that the mixture is broken evenly to form artificial fractures; (3) under the corresponding temperature, the hydrate decomposes to produce gas by depressurized exploiting; (4) the gas-liquid mixture exploited by the exploiting well is separated into liquid and gas in the gas-liquid separation device to collect liquid and gas.