Chinese Academy of Sciences

Zhaoyang Chen

Xiaosen Li

Gang Li

Yu Zhang

Yi Wang

Zhiming Xia

Ningsheng Huang

Chungang Xu

Yisong Yu

Kefeng Yan

Pengfei Shen

Xuke Ruan

Jiayuan Zhou

Jinming Zhang

Jianwu Liu

Qiunan Lv

A system and method for exploiting a marine natural gas hydrate resource including a vertical well, comprising a sleeve configured to penetrate through a marine layer and a hydrate reservoir covering layer, and penetrate downwards into a natural gas hydrate reservoir; a section of the sleeve in the natural gas hydrate reservoir is provided with a perforating channel; a horizontal well, connected to a bottom end of the sleeve; a production string, disposed in the sleeve and extending downwards into the horizontal well, wherein a bottom of the production string is provided with a gas/water collection inlet; a hot water injection pipe, disposed in the production string; and a bottom of the hot water injection pipe is provided with a hot water injection opening; and a gas bladder, disposed in the horizontal well and connected to the hot water injection opening in the hot water injection pipe.

System and method for exploiting marine natural gas hydrate resource

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.

Device and method for simulating layered stratum containing natural gas hydrates

A system for exploiting natural gas hydrate with downhole gas-liquid synergic depressurization includes a casing configured to form an exploitation well. An upper end of the exploitation well is connected to a produced gas collection pipeline, and the produced gas collection pipeline is configured to be connected to a produced gas recovery system. A perforated channel is distributed in a section of the casing located in a natural gas hydrate reservoir. A tubular string component assembly is mounted in the exploitation well, and includes an outer string, a production tubular string and an auxiliary riser. A first check valve is mounted at the bottom of the outer string, a gas supply pipeline is connected into an upper portion of the outer string, and a flow controller is mounted in the gas supply pipeline. The production tubular string is mounted in the outer string.

System and method for exploiting natural gas hydrate with downhole gas-liquid synergic depressurization

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.

Natural gas hydrate exploitation experimental device and method for full-sized production wells

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.

Divisible experimental device and method for sand production and sand control during natural gas hydrate exploitation

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.

Comprehensive three-dimensional exploitation experimental system for large-scale and full-sized exploitation wells

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.

Device for measuring stratum deformation during natural gas hydrate exploitation

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.

Flow field measurement device and method for scale model of natural gas hydrate reservoir

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.

Device and method for gas-water-sand separation and measurement in experiment of natural gas hydrate exploitation

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.

Physical characterization device and method for scale model of natural gas hydrate reservoir

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.

Method and device for exploiting natural gas hydrate from marine rock

An in-situ hydraulic jet exploiting device and method of a low-permeability natural gas hydrate reservoir. The device includes a high-pressure reaction kettle configured for formation, fracturing and exploiting of a hydrate, a stable-pressure gas supply module configured to adjust and control a gas flow rate, a constant-speed constant-pressure liquid supply module configured to control a liquid flow rate or keep liquid injection pressure constant, a thermostatic water bath configured to provide a constant-temperature environment for a device system, a back-pressure module configured to automatically control an exploiting rate or exploiting pressure, an in-situ hydraulic jet permeability enhancement module, a data collection and processing module configured to collect and process basic system parameters, and a pipeline connecting various components.

In-situ hydraulic jet exploiting device and method of low-permeability natural gas hydrate reservoir

A hydrate formation promoter and the use thereof in methane storage. The hydrate formation promoter is a mixed aqueous solution including cyclopentane, sodium dodecyl sulfate and water, wherein a volume fraction of the cyclopentane is 5% to 23.4% and a mass fraction of the sodium dodecyl sulfate is 0.01% to 0.08%. The hydrate formation promoter can realize effective and rapid formation of methane hydrate at approximate room temperature (25&#xb0; C.), and can remain stable at higher temperatures.

Hydrate formation promoter and use thereof in methane storage

A method for recovering gas in natural gas hydrate exploitation is disclosed, in which a gas-water mixture at a bottom of a exploitation well is delivered to an ocean surface platform through a marine riser, by adopting the gas-lift effect of methane gas derived from the dissociation of natural gas hydrate, so as to achieve a controllable flowing production of marine natural gas hydrate. In the startup stage, the pressure in the bottom of the well is decreased by the gas-lift effect of the injected gas to allow dissociation of the hydrate. In the flowing production stage, the flowing production is achieved by the gas-lift effect of the gas derived from the dissociation of the natural gas hydrate, wherein a seafloor gas tank is employed to control the flowing rate and replenish the consumed gas.

Method and system for recovering gas in natural gas hydrate exploitation

Disclosed is an experimental device for studying the sediment yield behavior and the radial deformation of porous media during the exploitation of natural gas hydrates, comprising a high-pressure reactor, a hydrate sample chamber, a simulated wellbore, a deformation measurement unit, an ambient temperature control unit, an outlet control unit, an inlet control unit and a data processing unit. Further disclosed is a method using the above-mentioned experimental device to carry out experiments. The experimental device and method according to the present invention can conveniently measure the deformation of the porous media during the decomposition of the hydrates and simulate the sediment producing situation in the wellbore, can simulate the sediment yield problem during the exploitation of natural gas hydrates as well as the gas-liquid-solid flowing problem in the wellbore during the exploitation of natural gas hydrates, and can accurately obtain the gas-solid-liquid three-phase yields in real time during the decomposition of natural gas hydrates. Being simple to operate and easy to control, and suitable for various sizes and shapes of reactors, it can provide basic experimental data and a theoretical basis for the technologies of hydrate exploitation.

Experimental device and method for studying relationship between sediment yield behavior and radial deformation of porous media during exploitation of natural gas hydrates

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Guangzhou, China

Zhaoyang Chen