359 results about "Hydrate decomposition" patented technology

A simulation device of an entire natural gas hydrate exploitation process includes a high pressure reaction kettle, a gas-liquid separation device, a hydrate accumulation simulation subsystem simulating a hydrate accumulation process, a hydrate formation drilling simulation subsystem simulating a hydrate formation drilling process, a hydrate exploitation simulation subsystem simulating a hydrate decomposition and gas production process, and a produced gas collecting and processing simulation subsystem simulating a produced gas collecting and processing process. A method for simulating an entire natural gas hydrate exploitation process includes a hydrate accumulation process, a hydrate formation drilling process, a hydrate exploitation process and a produced gas collecting and processing process. With this simulation device and method, the external environment can be truly simulated, so that the authenticity and accuracy are better, and the entire natural gas hydrate exploitation process is continuously simulated and comprehensively evaluated to provide guidance for natural gas hydrate exploitation.

The invention provides an experimental method and a device thereof for simulating the exploitation of gas hydrates, wherein the method includes: underlying gas hydrates are generated in a reaction kettle which is provided with water-containing porous medium fill areas. In the step, experimental gas is led in from the lower part of the reaction kettle, thereby spreading the gas from bottom to top into the porous medium fill areas to generate hydrates. Then the hydrates generated are decomposed by adopting a voltage drop method, a heat injection method and or a chemical injection method; and thegas produced after decomposition of the hydrates is discharged out of the reaction kettle, thus simulating the process of exploitation of hydrates. In addition, the invention also provides a device specially designed for implementing the experimental method. The method and the device not only can make three-dimensional simulation of generation circumstance of the gas hydrates in marine sedimentsand the gas hydrates symbiotic with underlying free gas, but also can simulate exploitation of the hydrates by combining a single principle with a multi principle, and can realistically simulate the exploitation process of the gas hydrates.

The invention provides a natural gas hydrate water discharge gas production exploitation device and an exploitation method of the natural gas hydrate water discharge gas production exploitation device, and belongs to the technical field of natural gas hydrate exploitation. A feeding cavity (12) communicated with a natural gas hydrate layer (29) is connected with an in-well gas-liquid separator (7), an exhaust cavity (8) of the in-well gas-liquid separator (7) is communicated with a gas production sleeve pipe (17), and a water discharge opening of the in-well gas-liquid separator (7) is communicated with a liquid storage cavity (2) arranged at the lower part. According to the exploitation method adopting the device, the natural gas hydrate layer (29) is firstly heated, the in-well gas-liquid separator (7) is utilized for separating gas-water mixture generated in the natural gas hydrate decomposition process, meanwhile, a liquid level monitoring device is utilized for regulating the water discharge speed of an electric submersible pump (4), and the decomposition speed of the natural gas hydrate is controlled. The device and the method have the advantages that the natural gas hydrate exploitation well liquid accumulation can be effectively prevented, the gas production efficiency is improved, the work is safe and reliable, the environment is protected, the service life is long, and the like.

The invention relates to a visual natural gas hydrate sediment mechanical property testing apparatus, belonging to the field of the measurement of basic natural gas hydrate physical properties. The visual natural gas hydrate sediment mechanical property testing apparatus mainly comprises an automatic-pressing triaxial apparatus main machine, an axial loading system, a confining pressure control system, a backpressure control system, a temperature control system, a data collection system and an X-ray CT (computed tomography) imaging system. The low-temperature high-pressure hydrate triaxial apparatus is organically combined with the X-ray CT imaging system, so that the testing on macro and micro mechanical properties of natural gas hydrate sediments can be synchronously carried out. The visual natural gas hydrate sediment mechanical property testing apparatus can simulate a stress state of a real reservoir stratum, macro and micro mechanical property data of the natural gas hydrate sediments can be acquired, the important significance on disclosing a deformation mechanism of the natural gas hydrate reservoir stratum and a triggering mechanism of geological hazards such as submarine landslide caused by the decomposition of natural gas hydrate can be realized, and an important guiding function for safely and high efficiently exploiting the natural gas hydrate can be realized.

The present invention relates to a sampler for gas hydrates by hole bottom freezing, the sampler comprises a fisher, a wire-line coring mechanism and an outer barrel, and it further comprises a refrigeration portion, a low temperature control portion and a frozen insulation sample portion, which constitute an inner barrel assembly located inside the outer barrel together, wherein a refrigerant in the refrigeration portion is injected into the frozen insulation sample portion under a control of the low temperature control portion, so that a cooling medium in the frozen insulation sample portion is always kept under a predetermined temperature, and a core sample of gas hydrates is frozen at the bottom of a drill hole. The invention also relates to a sampling method using the sampler as mentioned above. In the invention, the temperature of the sample can be decreased by using an external cooling source to suppress hydrate decomposition, the critical decomposition pressure of gas hydrates can be reduced by active decreasing the temperature of the sample, and the stability of gas hydrates is maintained by a passive pressure drop. The method of the present invention need not to keep the pressure of the sample, and is simple to obtain a core sample of gas hydrates with higher fidelity.

The single well operation process for exploiting hydrate from sea bottom includes the following steps: drilling one horizontal section in the top of hydrate layer to expand the hydrate layer exposing area; connecting slotted pipe to the end of the horizontal section to increase the passage area of the recirculated medium; forming one circulation with the oil pipe and the annular space and with water as the circulating medium; injecting hot water into oil pipe from the platform and returning hot water to the vertical section to exchange energy with stratum and to decompose the hydrate; backing upwards the mixed liquid through the annular space; adopting sand preventer in the horizontal section to leave sand in the storing layer; and treating the exploited water and reinjetting to underground for reuse and separating from sea water to avoid environmental pollution.

The invention provides a mining method of undersea natural gas hydrates and a device thereof. The undersea natural gas hydrates are mined by utilizing renewable energy sources, abundant solar energy in marine areas is collected and transformed into electric energy which is transformed into heat energy for heating a stratum containing the natural gas hydrates which is a certain depth from a submarine stratum so as to lead the hydrates therein to be decomposed, and the natural gas generated from decomposing is collected. The device comprises a solar power generating system arranged on a sea production platform and a distributor comprising an electric heater, wherein, the solar power generating system is connected with the electric heater by an insulated cable so as to supply power for the electric heater. The method has the advantages of high efficiency, low energy consumption, strong feasibility, and safety and environmental protection; in addition, the device is simple and the cost is lower.

The invention relates to a method for low-pressure processing of coal bed gas, comprising the steps of: introducing the coal bed gas into a hydration reactor from the bottom part of a hydration reactor so as to be contacted with hydrate working liquid in the hydration reactor, leading methane contained in the coal bed gas and water in the hydrate working liquid to generate hydration reaction to form a hydrate which is removed from the coal bed gas; meanwhile, the purified gas is obtained after the methane in the coal bed gas is removed; wherein the operation pressure of the hydration reactor is 0.11-0.85MPa, and the temperature is 3-18 DEG C. The formed hydrate can be further introduced into a hydrate decomposition device for decomposition, thereby obtaining the methane with high concentration. The invention simultaneously relates to a device for realizing the method for low-pressure processing of the coal bed gas. The invention can safely purify the oxygen-containing coal bed gas under lower pressure and remove the contained methane to be lower than 0.05 molar fraction, thereby reducing the emission of the methane, reducing the greenhouse effect and simultaneously avoiding the risk of explosion.

The invention discloses a mechanical-thermal hydrate exploiting method. The mechanical-thermal hydrate exploiting method comprises the following steps: excavating a hydrate stratum, crushing hydrate sediment into hydrate sediment granules, and conveying the hydrate sediment granules into a decomposing chamber; stirring and mixing relatively hot seawater and the hydrate sediment granules in the decomposing chamber, partially decomposing the hydrate sediment granules, separating the obtained mixture, and removing the separated sediment; upwardly conveying the remaining mixture along an exploiting shaft, further decomposing the hydrate in the mixture in the conveying process, and separating the remaining mixture and generated gas from the sediment in the mixture; and collecting the obtained gas on an exploiting platform. By the method, hydrate decomposing heat can be supplied by a huge heat source from seawater and convective heat transfer; expansion energy of gas which is generated in a centralized way can be made full use; backfill of the sediment can restore certain stratum strength; and leakage of the hydrate decomposing gas from a covering layer can be avoided.

The invention relates to an experiment device and a method for deepwater shaft multiphase flow containing natural gas hydrate phase changes. The experiment device comprises a deepwater shaft natural gas hydrate forming and decomposition simulator and a simulator for deepwater shaft multiphase flow containing natural gas hydrate phase changes. The experiment method comprises the steps of performing deepwater shaft natural gas hydrate forming simulation experiment; determining the amount of the formed natural gas hydrate; performing deepwater shaft natural gas hydrate decomposition simulation experiment; determining the decomposition speed of natural gas hydrate; and performing simulation experiment of the deepwater shaft multiphase flow containing natural gas hydrate phase changes. The experiment device and the method for deepwater shaft multiphase flow containing natural gas hydrate phase changes have the advantages of capable of achieving simulation of the deepwater shaft multiphase flow containing natural gas hydrate phase changes, including the natural gas hydrate forming simulation experiment, the natural gas hydrate decomposition simulation experiment, and the simulation experiment of effects of natural gas hydrate decomposition on shaft multiphase flow regularities in deepwater shafts.

The present invention relates to an apparatus and a method for monitoring a hydrate decomposition area under different drilling and production processes. The apparatus for monitoring hydrate decomposition area under different drilling and production processes comprises a reaction unit, an auxiliary unit and a determination unit; the reaction unit is used to simulate the hydrate storage layer environment, provide a place for generation and decomposition of a hydrate, simulate a hydrate heat-injection exploitation process, a hydrate pressure-reduction exploitation process and a hydrate CO₂ displacement exploitation process, and also analyze the hydrate decomposition status at various areas by calculating the hydrate decomposition rate, thereby evaluating and optimizing the drilling and production process; the auxiliary unit is used to provide a gas source and a liquid source for the reaction unit, and simulate different hydrate drilling and production processes; and the determination unit is used to measure the hydrate decomposition rate in different drilling and production processes.

The invention relates to a mineshaft multiphase flow device for simulating deep-water oil and gas production. In the technical scheme, the simulation of ocean low temperature environment condition is completed by an environment temperature flowing maintaining system, wherein a liquid part of high pressure flow environment is mainly formed by the connection of a water tank, a high pressure water pump, a flow liquid temperature control system and a flow meter, a gas part is mainly formed by the connection of a gas compressor, a high pressure gas tank, a drier and a gas flow meter, and a gas-liquid mixture is completed through a bubble generator and then flows through a control valve to enter into a main mineshaft; natural gas hydrate decomposed injected gas is simulated, and flows through acontrol system and a gas injection pipeline to enter into the main mineshaft; mixed liquid enters into a gas-liquid separating tank through a backflow pipeline to complete circulation. The invention has the advantages of capability of simulating deepwater low temperature oil and gas production at 1000 meters depth of water, further researches on multiphase flow law inside the mineshaft under deepwater flow condition, and establishes a multiphase flow state mechanical model of the deepwater mineshaft and a computing method.

The invention relates to a low temperature and low hydration heat cementing concrete system used in the natural gas hydrate layer cementing field. The objective of the invention is to effectively reduce the heat release of the cement hydration, prevent the hydrate from decomposing because of large heat and reduce the harm of the hydrate to the cementing. The whole performance of the cement under the low heat release condition is improved by adding materials which can reduce the whole hydration heat release of the cement using G grade oil well cement as base material. (1) The proper addition of superfine slag with a specific surface area between 6000 and 12000cm2/g can make sure the strength properties of the early and later stage of the cement. (2) The hydration heat is further reduced by adding fly ash with a lower hydration activity. (3) An amount of gypsum component is added so that the cement paste has certain expansion property at a low temperature to prevent the cement paste shrinking at a low temperature. The low temperature and low hydration heat cementing concrete provided by the invention has an obvious effect for reducing the whole cement hydration heat and a good effect for preventing the deep water hydrate decomposition.

The invention provides a cutter exploitation method of seabed natural gas hydrates. The method employs a seabed exploitation vehicle, a sea level decomposition and storage system, and a waterpower conveying system for connecting the seabed exploitation vehicle as well as the sea level decomposition and storage system. The seabed exploitation vehicle comprises a reamer, a reamer arm, a crawler type running gear as well as a power and control system, and the like, and is used for cutting and fragmenting the seabed natural gas hydrate. The waterpower conveying system comprises an auxiliary slurry pump, a conveying flexible pipe, a buoyancy ball, a main slurry pump, a conveying hard tube, and the like, and the system is used for conveying the natural gas hydrates which is fragmented by the exploitation vehicle to the sea level decomposition and storage system. The decomposition and storage system comprises a decomposer, a storage container, a mine tailing pipe, and the like, and is used for decomposing and separating the natural gas hydrates which are conveyed by the conveying system and collecting the natural gas hydrates in the storage container, and the separated seabed deposits and other refuses are discharged to the seabed. The cutter exploitation method of seabed natural gas hydrates has high production efficiency and controllable exploitation process, 'air bag' and the like are not needed to construct, and the method has good application prospects.

The invention relates to a method for using original catalyst oxidization thermal chemical method to product natural gas hydrate, and a relative device, wherein said method is characterized in that: pouring hydrate decompose accelerant into the hydrate storage layer to decompose the natural hydrate; using oxidant to catalyze and oxidize the fuel to heat the heat liquid in the catalyst oxidization burner; then pumping the liquid into storage layer to support the heat needed in the decomposition of natural gas hydrate; then pouring the CO₂ gas generated by burning into hydrate storage layer; and the inventive device comprises: catalyze oxidize burner 14, as one coaxial sleeve reactor, while the tube is the catalyze oxidize burning area and the frame is divided into preheating section and heat exchanging section. The invention can combine the mechanical method and the CO₂ exchange method, to improve the producing speed and confirm the stability of seabed.

The invention discloses a high-pressure experimental system for simulating leakage type natural gas hydrate formation/decomposition, which comprises a visual large-volume high-pressure transparent reaction kettle, a gas supply system, a temperature control system, a power system and a data acquisition system, wherein the gas supply system is connected with the reaction kettle and can provide flowing gas at required pressure, temperature and humidity for the reaction kettle; the temperature control system is used for providing the required temperature and the humidity for the reaction kettle; the power system is connected with the reaction kettle and can provide a vacuum environment for the reaction kettle and ensure smooth circulation of the gas; and the data acquisition system is connected with the reaction kettle and used for acquiring data, such as the temperature, the pressure, electrical conductivity, flow rate and the like in real-time, recording and processing the data and performing observation experiments. The high-pressure experimental system can simulate the process that the gas forms hydrates in three sections of different phases while moving under different flow rates, thereby describing characteristics of heat transfer and mass transfer of the hydrates formed by the leaked gas in a leakage system and providing references and similar parameter data for researchingthe hydrates under actual sea bottom similar conditions. Simultaneously, the experimental system and a method can further develop the corresponding hydrate decomposition research.

The invention discloses a hydrate reservoir developing well group structure and method using geothermal energy. The well group structure mainly comprises a horizontal injection well and a comprehensive well, wherein cold fluid is injected into the horizontal injection well, flows into a directional communication well section of the comprehensive well on the top after being heated by a hot dry rock reservoir, and flows upwards back to a hydrate reservoir, the heated fluid flows into the hydrate reservoir through a perforation section to provide energy for hydrate decomposition, and the mixed fluid of natural gas generated by decomposition and the injected fluid is extracted from a horizontal production well section of the comprehensive well on the top under the influence of gravity and pressure. According to the hydrate reservoir developing well group structure and method using the geothermal energy, heat of the hot dry rock reservoir is transmitted to the hydrate reservoir through heat transport fluid, at the same time, a plurality of horizontal well sections are chosen to improve the heat exchange efficiency, and deficiencies such as low heat utilization rate and high development cost of a traditional thermal excitation method are made up for. The hydrate reservoir developing well group structure using the geothermal energy has simple equipment and is convenient to operate, high in economic efficiency and capable of providing guidance for implementation of hydrate reservoir production increasing measures.

The invention discloses a natural gas hydrate exploiting method, which comprises the following steps: drilling a communicated well in a hydrate reserving layer; laying a screen pipe on the horizontal segment for well completion and putting a throttling device into a well completion pipe; next, injecting hot water or a hydrate decomposition accelerator into an injection well. At the initial exploiting stage, under the double action of the local low pressure generated by the downstream of the throttling device and the thermal energy of the fluid or the hydrate decomposition accelerator injectedinto the injection well, the hydrate decomposition is started, and then the natural gas generated via decomposition enters the communicated well and flows along with the fluid in a well sleeve to flow out of a production well; and after a period of exploiting, the hydrate near the throttling device is decomposed, and a new flowing channel is formed in the hydrate reserving layer, so that the action area of the fluid on the hydrate reserving layer is enlarged, and the heat and mass transferring efficiency and the hydrate exploiting efficiency are improved. With the increasing of the decomposednatural gas, the gas content in the well sleeve is increased and the pressure in the well sleeve is lowered gradually by reducing the injected discharging volume, so that the decompression exploitation can be realized, and the hydrate exploiting efficiency can be improved.

The invention discloses a natural gas hydrate sediment triaxial test device, and belongs to the field of testing the mechanical properties of natural gas hydrate sediment. The device comprises a triaxial test device main machine, a temperature control system, a pore pressure control system, a confining pressure control system and a computer data acquisition and control system. The triaxial test device main machine, which is in a dual-pressure-chamber structure, can be used for accurately measuring volume change in the sediment in a natural gas hydrate decomposing process; a load sensor is arranged inside the pressure chamber and is capable of improving the precision of intensity data; a pre-cooling hollow cavity is formed inside a base to pre-cool pore gas and pore water which enter a sample, so as to relieve the decomposition of the natural gas hydrate in a saturated water process and to improve the precision of temperature control; in a sample installation process, a quick coupling is adopted for connection, so that the operation is convenient and rapid. The device can simulate the natural gas hydrate decomposing process under mining conditions, so as to achieve the high-precision temperature control, and accurate measurement of intensity and volume change; and the device has great significances for understanding the mechanical properties of the natural gas hydrate sediment and assessing the stability of a reservoir.

The invention discloses a device and method for exploiting terrestrial natural gas hydrates through CO2 fracturing and displacing. The device is composed of a CO2 control system, a natural gas hydrate control system and a power generation control system; the power generation control system is connected to the CO2 control system and the natural gas hydrate control system, and the CO2 control system is connected with the natural gas hydrate control system. According to the device and method, by combining CO2 dry fracturing with CO2 displacing, the problems that when the hydrates are exploited only by adopting CO2 displacing, the speed and the efficiency are low are solved, hydrate exploiting and greenhouse gas burying and storing are integrated into a whole, and meanwhile the stability of a hydrate layer in the exploiting process is guaranteed. Information such as the pressure, the temperature and the permeability of the hydrate layer can be collected in real time in the fracturing and exploiting process, the exploiting speed of hydrate decomposition gas and improvement treatment on the reservoir permeability are adjusted and controlled according to the information, and therefore the purpose of efficient and safe exploiting is achieved.

The invention discloses a method and a device for integrated utilization of natural gas pipe network pressure energy refrigeration and hydrate, wherein the method comprises the steps of carrying out shunting on the high pressure pipe network natural gas of a natural gas gate station; carrying out depressurization refrigeration on the natural gas which meets the instantaneous demand of urban pipe networks and storing the cold energy through cooling mediums; leading the depressurized natural gas to enter downstream urban pipe networks; leading another part of high pressure natural gas to enter ahydrate generation tower to generate natural gas hydrate slurry which flows into a hydrate storage tank for storage; using the cooling mediums in a low-temperature storage tank to provide cold energyfor the hydrate storage tank and the generation tower to generate the hydrate when in gas consumption trough; and heating to vaporize the hydrate in the storage tank for supplementing the downstreampipe networks when in gas consumption peak; and simultaneously applying the cold energy generated by the decomposition of the hydrate to cold water air conditioners and cold storages. The invention uses the natural gas pressure energy refrigeration to generate the natural gas hydrate, simultaneously applies the cold energy of the vaporization of the hydrate to air conditioners and cold storages, thus realizing the peak regulation function of the urban natural gas pipe networks and the electric network, and greatly improving the energy utilization efficiency.

The invention discloses a kind of marine natural gas hydrate drilling device and equipment. The method incldues the following steps: exploit the natural gas hydrate layer in the sea floor; separate the silt in the sea floor through silt separating equipment, then transmits the mixture of natural hydrate, resolved gas and water into the resolving device on the sea-level; channel the sea water with higher temperature into the resolving device on to resolve natural gas hydrate; channel out the resolved natural gas and sea water separately. The device includes drilling facility, silt separating equipment, hydrate resolving device and natural gas leadingo ut pipeline, etc. The method and device of the invention well overcome the drawbacks of the existing method for exploiting marine natural gas hydrate, its equipment is simple, operation is easy, cost is low, working efficiency is high, and can apply to extensive exploitation of marine natural gas hydrate.

The invention discloses an exploitation method and equipment for natural gas hydrate on the shallow layer of the seabed. Operation is conducted on a water surface exploitation ship, a seabed exploitation device is controlled to conduct physical crushing on shallow strata containing the natural gas hydrate, crushed mixtures are conveyed to a seabed hydrate decomposition device, a seabed heating method is mainly adopted, the solid state existence condition of the natural gas hydrate is changed, the natural gas hydrate contained in the mixtures is decomposed out in a controllable mode, and gasified natural gas is conveyed to deck equipment along a continuous oil tube for being processed and stored. The whole exploitation equipment has a self-walking function, exploited energy can be utilized to generate power, power required by self walking is provided, local sealed heating is adopted for decomposition of the hydrate, and therefore the exploitation method has no influence on biology of the seabed.