40 results about "Hydrate dissociation" patented technology

The invention provides an experimental method and an experimental device for measuring sand produced by hydrate dissociation and seepage. The experimental method comprises the following steps: filling a sample tube with an experimental material to simulate a hydrate sediment layer; placing the sample tube in an environment with the pressure of 8-30MPa and at a temperature of 0-10 DEG C; filling the sample tube with methane gas and water to simulate hydrate dissociation and production; simulating hydrate dissociation and seepage through a filter screen, wherein a water-sand-gas mixture in the sample tube passes through the filter screen and then methane gas and a mixture of water and part of sand flow out; and enabling the methane gas to flow upwards through a flow meter to obtain the volume of the methane gas, and enabling the water and sand mixture to flow downwards through a nuclear magnetic resonance measurement module to obtain the volume of sand. The experimental method and the experimental device can be used for measuring the temperature and pressure, the sand production rate, the gas output and the water flow during hydrate dissociation and seepage in real time, thereby providing a scientific basis and a technical support for predicting sand produced by hydrate production and making control measures.

In hydrate-based desalination or other water purification conducted using naturally buoyant or trapped-gas-assisted buoyancy hydrate in a hydrate fractionation column, a portion of fresh or purified product water is extracted from an upper, hydrate dissociation region of the fractionation column and reintroduced into a lower portion of the fractionation column at a point above but generally near a product water / saline water interface. The difference in density between the reintroduced product water and the fluid in the hydrate fractionation column above the point of reintroduction (water, hydrate, and gas) drives a natural circulation system which enhances the rate at which hydrate rises into the hydrate dissociation region.

It is an object of the present invention to provide a deriving technique with economy and technical difficulty improved without depending on fuel consumption for a heat source when methane gas is derived from a methane hydrate layer. Warm water is pumped up by a pump from an underground aquifer present 1000 to 1500 m below the seabed, geothermal energy is caused to flow through a permeable layer below a methane hydrate layer, a dissociation boundary surface of an un-dissociated area of the methane hydrate layer is dissociated to generate methane gas, the methane gas is led into a production well from peripheral areas and through a gas inlet screen and caused to rise so that the methane gas is collected on the sea.

Method intended for continuous detection and control of hydrate formation at any point of a pipe carrying multiphase petroleum fluids. The method uses a compositional code allowing to simulate the circulation modes and conditions at any point of the pipe, considering that the fluid mixture is substantially continuously at equilibrium, that the composition of the multiphase mixture is variable all along the pipe and that the mass of each constituent of the mixture is globally defined by a mass conservation equation regardless of its phase state. The thermodynamic hydrate formation conditions are detected after a particular stage of grouping the petroleum fluids into pseudo-components so as to isolate the hydrate forming components, with definition for each one of a mass fraction and of a certain number of characteristic physical quantities, and the data relative to these particular fractions are applied to the modules so as to determine at any point the hydrate dissociation temperature (Td). A control device (C) can also be used to compare the temperature of the petroleum fluids with this dissociation temperature (Td), and measures designed to fight hydrate formation can be applied under the control of this control device (C). The method can be applied for deep-sea petroleum production for example.

Disclosed herein is an apparatus and method for simulating a submarine landslide. The apparatus includes an inclined flume; a plurality of sedimentary layers which are stacked on top of one another in the flume and tapped; water which is charged into the flume on the sedimentary layers in such a way that the surface of the water is formed in the flume; and a plurality of injectors which are provided in a bottom of the flume so as to be movable upwards or downwards with respect to the flume and inject gas or water into the sedimentary layer. The sedimentary layers are changed in pressure and temperature by the gas or water injected from the injectors into the sedimentary layers so that an artificial slope collapse is caused, whereby a water wave is generated in the flume.

The present invention provides a method for continuous separation of methane, carbon dioxide and hydrogen sulfide from biogas by hydrate method, and a three-stage gas separation device for implementing the method. High purity methane is separated by a first stage hydrate dissociation tower working at the temperature of 273.7K-283.1K and under the pressure of 1.324MPa-4.502MPa, high-purity carbon dioxide is separated by a second stage hydrate dissociation tower working at the temperature above 272.8K-288.7K and under the pressure of 0.093MPa-0.499MPa; high-purity hydrogen sulfide is separated by a third stage hydrate dissociation tower working at the temperature above room temperature and under the pressure above atmospheric pressure, and the three-stage gas separation device can be controlled by a written program by a computer to run automatically and select the proper working condition. The gas-liquid contact efficiency, hydrate formation rate, separation process target gas recovery rate and gaseous product purity are improved, hydrate formation heat removal is enhanced, high pressure hydrate system gas, liquid and solid three-phase automatic separation can be achieved, and the method can replace the existing technology, and can be used in production of continuous separation of methane, carbon dioxide and hydrogen sulfide from biogas by industrialized hydrate method.

The disclosure discloses a method for obtaining formation parameters of a gas hydrate reservoir through well testing interpretation, which comprises: (1) establishing a physical model for well testing interpretation of the gas hydrate reservoir according to multiphase flow, hydrate dissociation, secondary hydrate formation and heat transfer exhibited in the well testing process of the gas hydrate reservoir; (2) establishing a mathematical model for well testing interpretation of the gas hydrate reservoir; (3) conducting spatial discretization and temporal discretization on the mathematical model, and adopting a finite volume method to obtain a numerical solution of bottom-hole pressure; (4) calculating a bottom-hole pressure variation curve and a production rate variation curve in the well testing process of the hydrate reservoir, and drawing theoretical curves of bottom-hole pressure difference and pressure difference derivative; and (5) matching a measured pressure curve with the theoretical curve to obtain the relevant formation parameters.

In hydrate-based desalination or other water purification conducted using naturally buoyant or trapped-gas-assisted buoyancy hydrate in a hydrate fractionation column, a portion of fresh or purified product water is extracted from an upper, hydrate dissociation region of the fractionation column and reintroduced into a lower portion of the fractionation column at a point above but generally near a product water / saline water interface. The difference in density between the reintroduced product water and the fluid in the hydrate fractionation column above the point of reintroduction (water, hydrate, and gas) drives a natural circulation system which enhances the rate at which hydrate rises into the hydrate dissociation region.

The invention discloses a well structure design and method for exploiting geothermal energy and gas hydrate reservoir at the same time of water injection. The design mainly comprises a dual branch injection well and a horizontal producing well, wherein cold fluid is injected into the dual branch injection well, heated by a geothermal layer and returned to the gas hydrate reservoir; the self-carrying heat is transmitted to hydrate, and the hydrate dissociation is promoted. The method comprises the steps that a well group system which is composed of the dual branch injection well and the horizontal producing well is built on the sea level, wherein the dual branch injection well comprises a vertical mineshaft which extends from the sea level to the geothermal layer, a first branch mineshaft which is located on the gas hydrate reservoir and a second branch mineshaft which is located on the geothermal layer; the cold fluid is injected into a wellhead oil tube of the dual branch injection well, the cold fluid enters an oil sleeve annulus at the tail end of the second branch mineshaft and is subjected to heat exchange with the geothermal layer, after the heated fluid enters the gas hydrate reservoir, the heat is transmitted to the gas hydrate reservoir, the hydrate dissociation is caused, and mixed fluid which is composed of natural gas and injection fluid generated by the dissociation passes through a hydraulic power fracturing fracture under the gravity and pressure effect and is exploited by the horizontal producing well. According to the well structure design and method, the geothermal energy provides energy for the hydrate dissociation, the shortages such as low heat utilization efficiency and high exploiting cost in a traditional thermal excitation exploiting method are overcome, the device is simple, the operation is convenient, the economy is high, and the well structure design and method can provide guidance for reasonable exploiting of the gas hydrate reservoir.

The invention provides a natural gas hydrate dissociation gas release rate calculation method and apparatus. The method comprises: according to a hydrate dissociation related theory basis, establishing a hydrate slurry dissociation kinetic model and fitting values of related parameters in the hydrate dissociation model; according to natural gas components, performing phase-state flash evaporation and performing calculation to obtain natural gas related parameters; obtaining an amount of substances of natural gas hydrate during initial natural gas hydrate dissociation and real-time temperature and pressure data after a dissociation reaction is performed; and according to the hydrate slurry dissociation kinetic model, the values of the related parameters in the hydrate dissociation model, the natural gas related physical parameters, the amount of the substances of the natural gas hydrate during the initial natural gas hydrate dissociation and the real-time temperature and pressure data after the dissociation reaction is performed, obtaining a natural gas hydrate dissociation gas release rate. The calculation method and apparatus are mainly applied to the aspects of natural gas hydrate mineral development, flow assurance of removal of natural gas hydrate freezing and plugging, natural gas hydrate storage and transport technology, hydrate separation and the like.

The invention discloses an experimental simulation method for hydrate production and a confining pressure loading and thermal insulation integrated system. The confining pressure loading and thermal insulation integrated system comprises a refrigerating machine, a hydraulic press, a temperature sensor and a liquid cavity; the temperature sensor is connected with the refrigerating machine and is used for feeding the temperature of the surface of a sample back to the refrigerating machine; the refrigerating machine is connected with the hydraulic press and is used for adjusting the temperature of liquid of the hydraulic press into the temperature of the surface of the sample; the hydraulic press is used for inputting the liquid to the liquid cavity, wherein the temperature of the liquid is adjusted by the refrigerating machine; and the liquid cavity is connected with the hydraulic press and is used for supplying a confining pressure to the sample through the circulating liquid, enabling the sample to be isolated from the heat of environments, receiving the liquid input by the hydraulic press and outputting the circulated liquid to the refrigerating machine. The confining pressure loading and thermal insulation integrated system can provide a practical environment for the accurate testing of temperature variation caused by hydrate dissociation in the hydrate production process and is very beneficial to the scientific research and future field monitoring of hydrate production which gets more and more attention.

A natural gas hydrate development simulation experiment device, which can simulate horizontal wells, control and change the production data such as bottomhole pressure and heat injection temperature of production wells, optimize development parameters, and can be used to study the temperature field in the process of hydrate synthesis and decomposition Spatial distribution, spatial distribution of saturation field, advancing speed of hydrate decomposition front, and hydrate decomposition mechanism. The natural gas hydrate development simulation experiment device includes: an injection system, a drilling fluid wellhead annular circulation system, a model system, a control system, a data measurement system, and a data acquisition and processing system.

The present invention relates to a method of enriching a gaseous effluent in acid compounds, which comprises the following stages:feeding into a contactor a feed gas comprising acid compounds and a composition comprising at least two liquid phases non-miscible with one another, including an aqueous phase, at least one amphiphilic compound and at least one mixture of promoters,establishing in said contactor predetermined pressure and temperature conditions for the formation of hydrates consisting of water, promoters and acid compounds,carrying the hydrates dispersed in the phase non-miscible in the aqueous phase through pumping to a hydrate dissociation drum,establishing in the drum the hydrate dissociation conditions,discharging the gas resulting from the dissociation enriched in acid compounds in relation to the feed gas.

The invention discloses an external discharge type continuous hydrate seawater desalination device, and belongs to the technical field of hydrate seawater desalination. The device comprises a high-pressure reaction kettle, a low-temperature seawater spraying system, a high-concentration seawater recycling system, a hydrate dissociation chamber and a gas intake and collection system. A gas hydration agent and seawater are introduced into the high-pressure reaction kettle to generate a hydrate, the hydrate is lifted out of the water surface for low-temperature seawater spraying by a hard filter screen, meanwhile, high-concentration seawater is discharged, seawater is reintroduced for next-step hydrate generation reaction, then a hydrate is discharged to the outer-layer hydrate dissociation chamber, dissociated fresh water is collected, and the gas hydration agent is collected and recycled, so as to implement highly concentrated production by virtue of a hydrate seawater desalination technology. At the same time of low-temperature seawater spraying, the high-concentration seawater is discharged and the seawater is reintroduced into the high-pressure reaction kettle to start a next-step hydrate generation process to implement continuous reaction for hydrate seawater desalination, so that the device is more compact in structure and more complete in function, and the economy is improved.

The present invention relates to a method of enriching a gaseous effluent with acid compounds, comprising the following stages:feeding into a contactor R1 a feed gas and a mixture of at least two liquid phases non-miscible with one another, including an aqueous phase, the feed gas containing at least acid compounds,establishing in said contactor predetermined pressure and temperature conditions for the formation of hydrates consisting of water and of acid compounds,carrying the hydrates dispersed in the phase non-miscible in the aqueous phase by pumping P1 to a hydrate dissociation drum R2,establishing in the drum the hydrate dissociation conditions,discharging the gas resulting from the dissociation enriched in acid compounds in relation to the feed gas.

The invention belongs to the technical field of hydrate application, and discloses a spillover type continuous hydrate seawater desalination device. The spillover type continuous hydrate seawater desalination device comprises a reactor, a hydrate dissociation device, a spraying system, a gas circulating system, a water circulating system and a high-concentration seawater recycling system. A hydrate is separated from a solution by virtue of the difference that the hydrate and seawater have different densities, so that a hydrate seawater desalination technology can be industrialized. Moreover, hydrate generation and dissociation devices are combined in the same container, and an overturning controllable opening and closing device is utilized, so that the utilization efficiency of a material is improved, and the problem of pore plugging caused by hydrate generation is effectively solved. At the same time of low-temperature seawater spraying, high-concentration seawater is discharged and the seawater is reintroduced into an inner reactor to start a next-step hydrate generation process to implement cyclic production of fresh water by virtue of a hydrate method.

Disclosed herein is an apparatus and method for simulating a submarine landslide. The apparatus includes an inclined flume; a plurality of sedimentary layers which are stacked on top of one another in the flume and tapped; water which is charged into the flume on the sedimentary layers in such a way that the surface of the water is formed in the flume; and a plurality of injectors which are provided in a bottom of the flume so as to be movable upwards or downwards with respect to the flume and inject gas or water into the sedimentary layer. The sedimentary layers are changed in pressure and temperature by the gas or water injected from the injectors into the sedimentary layers so that an artificial slope collapse is caused, whereby a water wave is generated in the flume.

The invention discloses a gas hydrate dissociation and reaction liquid recovery device. The device comprises a three-phase separator, a gas hydrate dissociation unit, a carbon dioxide collection tank,an absorption liquid regeneration unit, a chemical absorption tower, an absorption liquid storage tank stored with an ethanol amine solution, a slurry pump, a counterbalance valve, a first anticorrosive pump, a second anticorrosive pump and a third anticorrosive pump. The device can be used for solving the problem of heat supply of hydrate dissociation; hydrate slurry entering a swirl chamber canbe kept in the chamber for a longer period, the slurry descends in the swirling process, gas rises, vacuum is formed in the swirling center in the swirling process, and hydrate dissociation is favored; an exhaust fan is beneficial to quick emission of dissociated gas, gas consumption can be reduced, and hydrate secondary generation which may possibly occur can be reduced; and as filter pores areformed in the conical bottom of the swirl chamber and the outer wall of the inner chamber of the lower chamber body, high-temperature regenerated gas enters inside the swirl chamber to perform heat convection with hydrate slurry, and the hydrate dissociation efficiency can be greatly improved.

The invention discloses a well structure design and method for exploiting geothermal energy and gas hydrate reservoir at the same time of water injection. The design mainly comprises a dual branch injection well and a horizontal producing well, wherein cold fluid is injected into the dual branch injection well, heated by a geothermal layer and returned to the gas hydrate reservoir; the self-carrying heat is transmitted to hydrate, and the hydrate dissociation is promoted. The method comprises the steps that a well group system which is composed of the dual branch injection well and the horizontal producing well is built on the sea level, wherein the dual branch injection well comprises a vertical mineshaft which extends from the sea level to the geothermal layer, a first branch mineshaft which is located on the gas hydrate reservoir and a second branch mineshaft which is located on the geothermal layer; the cold fluid is injected into a wellhead oil tube of the dual branch injection well, the cold fluid enters an oil sleeve annulus at the tail end of the second branch mineshaft and is subjected to heat exchange with the geothermal layer, after the heated fluid enters the gas hydrate reservoir, the heat is transmitted to the gas hydrate reservoir, the hydrate dissociation is caused, and mixed fluid which is composed of natural gas and injection fluid generated by the dissociation passes through a hydraulic power fracturing fracture under the gravity and pressure effect and is exploited by the horizontal producing well. According to the well structure design and method, the geothermal energy provides energy for the hydrate dissociation, the shortages such as low heat utilization efficiency and high exploiting cost in a traditional thermal excitation exploiting method are overcome, the device is simple, the operation is convenient, the economy is high, and the well structure design and method can provide guidance for reasonable exploiting of the gas hydrate reservoir.

The invention discloses an experimental simulation method for hydrate production and a confining pressure loading and thermal insulation integrated system. The confining pressure loading and thermal insulation integrated system comprises a refrigerating machine, a hydraulic press, a temperature sensor and a liquid cavity; the temperature sensor is connected with the refrigerating machine and is used for feeding the temperature of the surface of a sample back to the refrigerating machine; the refrigerating machine is connected with the hydraulic press and is used for adjusting the temperature of liquid of the hydraulic press into the temperature of the surface of the sample; the hydraulic press is used for inputting the liquid to the liquid cavity, wherein the temperature of the liquid is adjusted by the refrigerating machine; and the liquid cavity is connected with the hydraulic press and is used for supplying a confining pressure to the sample through the circulating liquid, enabling the sample to be isolated from the heat of environments, receiving the liquid input by the hydraulic press and outputting the circulated liquid to the refrigerating machine. The confining pressure loading and thermal insulation integrated system can provide a practical environment for the accurate testing of temperature variation caused by hydrate dissociation in the hydrate production process and is very beneficial to the scientific research and future field monitoring of hydrate production which gets more and more attention.

The invention belongs to the technical field of geotechnical engineering, and provides a modeling method of a sediment multi-field coupling model taking hydrate decomposition into account. According to the modeling method, on the basis of a pore-medium mechanical basic theory, in combination with the mechanical characteristics, flow characteristics and heat-transfer characteristics of hydrate sediment, control equations and constitutive equations of physical and mechanical behaviors of the hydrate sediment are given. By the adoption of a PDE module in COMSOLM ultiphysics software, the control equation discretization of temperature, pressure and saturation degrees is achieved, an outer material interface in a structural mechanical module is adopted, and a hydrate-sediment critical-state constitutive model based on a thermodynamics method is embedded. Meanwhile, a return mapping algorithm of a backward euler integral format is adopted, C++ language is adopted to write a model program, and numerical simulation and analysis, taking the hydrate decomposition process into account, of the physical and mechanical behaviors of the sediment are achieved.

The invention discloses a simulation and observation system for submarine landslide caused by natural gas hydrate decomposition. The simulation and observation system comprises a mechanical support, a heating decomposition unit and a deformation measurement unit, wherein the mechanical support is used for providing a platform and support for the heating decomposition unit and providing an observation area for the deformation measurement unit; the heating decomposition unit is used for heating an observed hydrate material so as to be decomposed and feeding back the amount of decomposition information to the deformation measurement unit; the deformation measurement unit is used for collecting a deformation signal in the mechanical support, observing the deformation process after the heating decomposition unit heats an observed test piece for decomposition according to the deformation signal, and obtaining the digital speckle images of the profile of the test piece in chronological order to generate the deformation information of the test piece for storage. The simulation and observation system solves the problems that in physical simulation experiments in a laboratory, the amount of decomposition and the decomposition area of material samples similar with a hydrate cannot be precisely controlled, the slope angle of the sample cannot be controlled, the landslide deformation cannot be quantitatively described and the like.

The invention provides an experimental method and an experimental device for measuring sand produced by hydrate dissociation and seepage. The experimental method comprises the following steps: filling a sample tube with an experimental material to simulate a hydrate sediment layer; placing the sample tube in an environment with the pressure of 8-30MPa and at a temperature of 0-10 DEG C; filling the sample tube with methane gas and water to simulate hydrate dissociation and production; simulating hydrate dissociation and seepage through a filter screen, wherein a water-sand-gas mixture in the sample tube passes through the filter screen and then methane gas and a mixture of water and part of sand flow out; and enabling the methane gas to flow upwards through a flow meter to obtain the volume of the methane gas, and enabling the water and sand mixture to flow downwards through a nuclear magnetic resonance measurement module to obtain the volume of sand. The experimental method and the experimental device can be used for measuring the temperature and pressure, the sand production rate, the gas output and the water flow during hydrate dissociation and seepage in real time, thereby providing a scientific basis and a technical support for predicting sand produced by hydrate production and making control measures.

The invention discloses a triaxial test device for natural gas hydrate deposits, which belongs to the field of testing the mechanical properties of natural gas hydrate deposits. The device includes a triaxial test device host, a temperature control system, a pore pressure control system, a confining pressure control system and a computer data acquisition and control system. The host of the triaxial test device adopts a double pressure chamber structure, which can accurately measure the change of sediments during the decomposition of natural gas hydrate; the load sensor is installed inside the pressure chamber to improve the accuracy of the strength data; The pore gas and pore water of the sample are pre-cooled to reduce the decomposition of natural gas hydrate in the saturated water process, and also improve the accuracy of temperature control; the sample installation process is connected by quick joints, which is convenient and fast. The device can simulate the decomposition process of natural gas hydrate under production conditions, realize high-precision temperature control, and accurately measure strength and volume change. It is of great significance to understand the mechanical properties of natural gas hydrate deposits and evaluate the stability of reservoirs.

The invention belongs to the technical field of hydrate application, and discloses a spillover type continuous hydrate seawater desalination device. The spillover type continuous hydrate seawater desalination device comprises a reactor, a hydrate dissociation device, a spraying system, a gas circulating system, a water circulating system and a high-concentration seawater recycling system. A hydrate is separated from a solution by virtue of the difference that the hydrate and seawater have different densities, so that a hydrate seawater desalination technology can be industrialized. Moreover, hydrate generation and dissociation devices are combined in the same container, and an overturning controllable opening and closing device is utilized, so that the utilization efficiency of a material is improved, and the problem of pore plugging caused by hydrate generation is effectively solved. At the same time of low-temperature seawater spraying, high-concentration seawater is discharged and the seawater is reintroduced into an inner reactor to start a next-step hydrate generation process to implement cyclic production of fresh water by virtue of a hydrate method.

The invention relates to a system and method for evaluating the instability of a seabed slope caused by hydrate decomposition, characterized in that it includes a pre-processing module, a core calculation module and a post-processing module; the pre-processing module includes a geometric model module, a material model Model module, physical grid model module and hydrate decomposition module; the geometric model module establishes the geometric model of the seabed slope and sends it to the physical grid model module and core calculation module; the material model module establishes the material model of the seabed slope and sends it to the physical grid The model module and the hydrate dissociation module; the mechanical model module establishes the mechanical model of the seabed slope and sends it to the core calculation module and the hydrate dissociation module; the physical grid model module establishes the physical grid model and sends it to the core calculation module; the hydrate dissociation The module calculates the amount of hydrate decomposition and sends it to the core calculation module; the core calculation module solves the stability data of the seabed slope and sends it to the post-processing module for display. The invention can be widely used in the stability evaluation of seabed slopes.