Abstract: 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.

Abstract: A divisible device and a method for sand production and sand control experiment for natural gas hydrate exploitation. The experimental device includes a reactor system, a feeding system, a separation and measurement system, a water-bath jacket system, a support and safety system, and a software recording and analyzing system. In the reactor system, the reactor units can be combined in different ways depending on the experimental conditions and purposes. The reactor units include: left/right reactor units, secondary reactor units, central reactor units, and caps. The combination of a left/right reactor unit with a cap gives a hydrate formation reactor without sand control screens. Combining the left/right reactor unit, secondary left/right reactor units and central reactor units with other accessories allows the reactor system to carry out the simulation experiments with either zero, one, or two view zones, and with either one or two wells.

Abstract: A comprehensive three-dimensional exploitation experimental system for large-scale and full-sized exploitation wells includes a reactor, configured to prepare a natural gas hydrate sample, for simulating an environment for forming a natural gas hydrate reservoir in seafloor sediments. The reactor includes a reactor body, an upper cover disposed at an upper surface of the reactor body, and a lower cover disposed at a lower surface of the reactor body; a gas introducing module, configured to introduce gas to the reactor during hydrate formation; a liquid introducing module, configured to introduce liquid to the reactor during hydrate formation; a temperature regulating module, configured to regulate a temperature in the reactor; a data collecting-processing-displaying module, configured to collect, store, process and display data of the comprehensive three-dimensional exploitation experimental system during an experiment.

Abstract: 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.

Abstract: A flow field measurement device and a method for a scale model of a natural gas hydrate reservoir are provided. The measurement device includes non-central vertical well pressure sensors, non-central vertical well outlet valves, communicating vessel valves, differential pressure sensors, a communicating vessel, a central vertical well outlet valve, and a central vertical well pressure sensor. By providing differential pressure sensors, between a measuring point of the central vertical well and a measuring point of each of the non-central vertical wells, to measure pressure differences, the flow field measurement device enables a reasonable distribution of a three-dimensional space inside the reactor to analyze gas-liquid flow trends in the reactor with a simulated flow field. Determining whether to turn on the differential pressure sensors according to a predetermination based on a feedback from the pressure sensors, allows flow field measurements in the reactor under both high and low pressure differences.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A device and a method for simulating layered stratum containing natural gas hydrates are provided. The device includes a reactor; wherein the reactor includes an upper cover, a lower cover, and a reactor body, wherein the upper cover and the lower cover are sealably attached to two ends of the reactor body to form a closed chamber; an overlying pressure layer, a superstratum layer, a hydrate layer and a substratum layer are sequentially formed throughout inside of the closed chamber from the upper cover to the lower cover, wherein each layer is respectively filled with different kinds of porous media and fluids and the each layer is provided with a stratal-fluid annular container; each stratal-fluid annular container has an outer periphery contacting an inner surface of the reactor body. The method is conducted using the device.

Abstract: A divisible device and a method for sand production and sand control experiment for natural gas hydrate exploitation. The experimental device includes a reactor system, a feeding system, a separation and measurement system, a water-bath jacket system, a support and safety system, and a software recording and analyzing system. In the reactor system, the reactor units can be combined in different ways depending on the experimental conditions and purposes. The reactor units include: left/right reactor units, secondary reactor units, central reactor units, and caps. The combination of a left/right reactor unit with a cap gives a hydrate formation reactor without sand control screens. Combining the left/right reactor unit, secondary left/right reactor units and central reactor units with other accessories allows the reactor system to carry out the simulation experiments with either zero, one, or two view zones, and with either one or two wells.

Abstract: 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.

Abstract: 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.

Abstract: A comprehensive three-dimensional exploitation experimental system for large-scale and full-sized exploitation wells includes a reactor, configured to prepare a natural gas hydrate sample, for simulating an environment for forming a natural gas hydrate reservoir in seafloor sediments. The reactor includes a reactor body, an upper cover disposed at an upper surface of the reactor body, and a lower cover disposed at a lower surface of the reactor body; a gas introducing module, configured to introduce gas to the reactor during hydrate formation; a liquid introducing module, configured to introduce liquid to the reactor during hydrate formation; a temperature regulating module, configured to regulate a temperature in the reactor; a data collecting-processing-displaying module, configured to collect, store, process and display data of the comprehensive three-dimensional exploitation experimental system during an experiment.

Abstract: A flow field measurement device and a method for a scale model of a natural gas hydrate reservoir are provided. The measurement device includes non-central vertical well pressure sensors, non-central vertical well outlet valves, communicating vessel valves, differential pressure sensors, a communicating vessel, a central vertical well outlet valve, and a central vertical well pressure sensor. By providing differential pressure sensors, between a measuring point of the central vertical well and a measuring point of each of the non-central vertical wells, to measure pressure differences, the flow field measurement device enables a reasonable distribution of a three-dimensional space inside the reactor to analyze gas-liquid flow trends in the reactor with a simulated flow field. Determining whether to turn on the differential pressure sensors according to a predetermination based on a feedback from the pressure sensors, allows flow field measurements in the reactor under both high and low pressure differences.

Abstract: 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.