JP4968998B2 - Gas hydrate mining system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technology for mining gas hydrates existing in the ground, and more particularly to a technology for procuring energy necessary for mining.
[0002]
[Prior art]
A gas hydrate is an icy solid substance composed of gaseous gas molecules and water molecules. Needless to say, a water molecule consists of one oxygen atom and two hydrogen atoms, but in the liquid state, a plurality of water molecules are bonded or separated, and dozens of water molecules are bonded. The state is called a cluster structure. The cluster structure is unstable in a liquid state, but becomes stable when pressurized or cooled, and the number of water molecules constituting the cluster structure increases.
[0003]
When sufficient gas molecules are present here, gas molecules are taken into the inside of the crevices and hydrates are generated. Those in which gas molecules are taken into the voids of the cluster structure are called gas hydrates, and those in which methane molecules are taken in are called methane hydrates.
[0004]
It has been clarified that gas hydrate containing a large amount of methane, that is, methane hydrate, exists in the natural world under permafrost and in submarine ground at a depth of about 500 m or less. The reserves are extremely large, and there are great expectations for next-generation energy resources to replace conventional fossil fuels.
[0005]
[Problems to be solved by the invention]
The existence of methane hydrate is supported by acoustic exploration and trial drilling of the seabed, but due to its unique properties, it is necessary to establish a unique drilling technique different from conventional fossil fuels such as oil and natural gas. .
[0006]
For example, gas fields that produce methane hydrate often exist at the end of extremely cold continents where it is difficult for humans to live, or on the ocean floor far away from the land. How to procure is a big problem.
[0007]
The present invention has been made in view of the above circumstances, and an object thereof is to independently procure gas hydrate existing in the ground without receiving energy supply from the outside.
[0008]
[Means for Solving the Problems]
As means for solving the above problems, the following configuration is adopted.
That engagement Ruga scan hydrate mining system of the present invention includes a separation means for separating at least a gas from a fluid state to a gas hydrate, the gas and water are mixed, a generator for generating a facility power, said separating means A drive unit that drives the generator using a part of the gas separated in step 1 as a fuel, an exhaust heat recovery heat exchanger that recovers exhaust heat of the drive unit, and a fluid before being introduced into the separation unit, Fluid heating means for heating with heat recovered by the exhaust heat recovery heat exchanger .
[0013]
In the present invention, a part of the mined gas is used as a fuel for the driving means of the generator and the heat source in the facility, or the exhaust heat of the driving means is used as the heat source in the facility. and Turkey be procured without the supply of energy of the power and heat from the outside consisting becomes possible.
[0014]
Further, the gas hydrate mining system according to the present invention includes a separation unit that separates at least a gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator that generates power in a facility, and the separation unit. And a driving means for driving the generator using a part of the separated gas as fuel, and a dehydrating means for dehydrating the remaining fluid from which the gas has been separated.
[0015]
In the present invention, the efficiency of transportation can be increased by dehydrating the gas hydrate.
[0016]
The above invention is characterized in that it comprises a gas recovery means for recovering a gas component contained in the water separated in the dehydration means.
[0017]
Water is rich in gas components and has sufficient utility value. Therefore, in the present invention, the yield of resources can be increased by recovering the gas component contained in the gas saturated water.
[0018]
Further, the gas hydrate mining system according to the present invention includes a separation unit that separates at least a gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator that generates power in a facility, and the separation unit. Drive means for driving the generator using a part of the separated gas as fuel, and slurry generating means for kneading the gas hydrate and water remaining after the gas is separated into a slurry, and And a concentrating means for lowering the water concentration in the slurry by separating water from the slurry.
[0019]
In the above invention , the concentration of the slurry concentrated in the concentration means is detected, and the concentration means is controlled based on the detection result.
[0020]
As a method of transporting the gas hydrate, a) a solid is packed and transported in a container, b) a slurry is transported through the pipeline, and c) a gas is transported through the pipeline. . Therefore, in the present invention, the mined gas hydrate is processed into a slurry form, and can be conveyed through the pipeline by adjusting the concentration appropriately.
[0021]
The above invention is characterized in that it comprises a gas recovery means for recovering a gas component contained in the water separated in the concentration means.
[0022]
Water contains abundant gas components, and this also has sufficient utility value. Therefore, in the present invention, it is possible to increase the yield of underground resources by recovering the gas component contained in the gas saturated water.
[0023]
Further, the gas hydrate mining system according to the present invention includes a separation unit that separates at least a gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator that generates power in a facility, and the separation unit. Drive means for driving the generator using a part of the separated gas as fuel, and hydrate heating means for heating the gas hydrate remaining after the gas is separated and evaporating the moisture to gasify it. It is characterized by that.
[0024]
In the above invention , the hydrate heating means heats the gas hydrate using the heat source in the facility.
[0025]
In the present invention, processing through the pipeline is possible by processing the mined gas hydrate into a gaseous state.
[0026]
Further, the gas hydrate mining system according to the present invention includes a separation unit that separates at least a gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator that generates power in a facility, and the separation unit. And a drive unit that drives the generator using a part of the separated gas as fuel, and a generating unit that generates gas hydrate using surplus gas as a raw material.
[0027]
In the present invention, it is possible to increase the yield of underground resources by generating gas hydrate using surplus gas generated in the separation means as a raw material.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of a gas hydrate mining system according to the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 shows a gas hydrate mainly containing methane (that is, methane hydrate) buried in the seabed and offshore facilities that excavate natural gas mainly composed of methane. In the figure, reference numeral 1 is a platform installed on the ocean, 2 is a gas hydrate mining system provided on the platform 1, 3 is a production facility for generating methane hydrate from the mined methane gas, and 4 is an underground hydrate. Hydrate piping for conducting methane hydrate from the layer H, 5 is a gas piping for conducting methane gas from the underground gas layer. Methane hydrate having a high concentration or generated on the platform 1 is transported on the sea by a transport ship 6 and stored in a storage facility 7 provided on land.
[0029]
In the gas hydrate mining system 2, as shown in FIG. 2, separation for separating methane gas from a fluid pulled up from the ground through the hydrate pipe 4 (this fluid contains methane hydrate, methane gas, and water). An apparatus (separating means) 10, a generator 11 that generates electric power required in the platform 1, and a prime mover (driving means) 12 that drives the generator 11 are provided.
[0030]
The separation device 10 employs a sedimentation tank that uses the specific gravity difference of methane hydrate, methane gas, and water, a cyclone separator that uses centrifugal force, a separator that uses inertial force, and the like. In addition to the function of separating methane gas from the fluid, the separation device 10 is provided with a function of separating water and gravel contained in the fluid and discharging them to the outside. A generator 11 having a capacity sufficient to meet the power demand in the platform 1 is employed. The prime mover 12 employs an internal combustion engine such as a gas engine or a gas turbine, and a part of the methane gas separated in the separation device 10 is used for the fuel.
[0031]
The gas hydrate mining system 2 supplies a heat medium to the exhaust heat recovery heat exchanger 13 and the exhaust heat recovery heat exchanger 13 as means for using the exhaust heat of the prime mover 12 as a heat source in the platform 1. A pump 14 is provided. Note that fresh water, which is easily separated separately, is used as the heat medium, but seawater that can be easily procured locally can also be used.
[0032]
The exhaust heat recovery heat exchanger 13 is connected to a combustor 15 for supplementing the amount of heat discharged from the prime mover 12. As the fuel for the combustor 15, a part of the methane gas separated in the separation device 10 is used as in the prime mover 12. The gas pipe 16 from the separation device 10 to the combustor 15 is provided with an adjustment valve 16a that adjusts the supply amount of methane gas as required.
[0033]
The heat recovered in the heat medium in the exhaust heat recovery heat exchanger 13 is supplied to equipment that requires heat in the platform 1 through the heat medium pipe 17. As a facility that requires heat, the hydrate pipe 4 includes a heat exchanger (fluid heating means) 18 that heats a fluid flowing through the inside and decomposes the gas hydrate to increase the gas concentration. In addition, there are various types of heat-requiring processes such as decomposition of methane hydrate in the seabed ground during excavation and decomposition of methane hydrate in the middle of the hydrate pipe 4 to prevent clogging of the pipe due to freezing. It is used for facilities.
[0034]
The gas hydrate mining system 2 generates a gas hydrate using the remaining methane gas obtained by subtracting the fuel supplied to the prime mover 12 and the combustor 15 from the methane gas separated by the separator 10 as a raw material. 19 is provided.
[0035]
Further, the gas hydrate mining system 2 includes a dehydrator 20 that dehydrates the methane hydrate separated in the separator 10 and the methane hydrate generated in the generator 19 to reduce the water content of the methane hydrate, A cooling device 21 that cools the methane hydrate having a reduced moisture content in the dehydrating device 20, a compacting device 22 that compacts the cooled methane hydrate, and a decompression device 23 that decompresses the molded methane hydrate. Is provided.
[0036]
The generator 11 generates all the electric power necessary for driving all devices installed in the platform 1 as well as the separation device 10, the generation device 19, the dehydration device 20, the cooling device 21, the consolidation device 22, and the decompression device 23. It is to be covered by the electricity that is used.
[0037]
In the gas hydrate mining system configured as described above, first, the fluid pulled up through the hydrate pipe 4 (mixed with methane hydrate, methane gas and water) is introduced into the separation device 10 to separate the methane gas. Is done. Furthermore, methane hydrate and water (including gravel) are roughly separated. Water containing gravel is discharged to the outside.
[0038]
Part of the methane gas separated in the separation device 10 is used as fuel for the prime mover 12, and drives the generator 11 to generate electric power used in the platform 1. Exhaust heat from the prime mover 12 is introduced into the exhaust heat recovery heat exchanger 13 to heat water as a heat medium. The heated heat medium is supplied through a heat medium pipe 17 to equipment that requires heat in the platform 1.
[0039]
When the amount of heat required in the platform 1 cannot be covered only by the exhaust heat of the prime mover 12, the adjustment valve 16a is opened and the combustor 15 is operated, and the generated heat is transferred to the exhaust heat recovery exchanger 13. It is introduced and used to heat the heat medium.
[0040]
When the amount of gas separated in the separation device 10 is small and the required amount of heat cannot be provided even when the combustor 15 is operated, a heat medium is introduced into the heat exchanger 18 and the gas hydrate contained in the fluid is contained. Is heated and decomposed to increase the amount of gas introduced into the separation apparatus 10.
[0041]
Methane hydrate separated in the separator 10 still contains a lot of water. Therefore, this methane hydrate is introduced into the dehydrator 20 and dehydrated, and the water content is reduced.
[0042]
If the methane gas is supplied to the prime mover 12 or the combustor 15 in the separator 10, the excess methane gas is introduced into the generator 19. In the production | generation apparatus 19, methane gas and water which are raw materials hydrate-react at a temperature higher than the freezing point and higher than atmospheric pressure to produce methane hydrate. The methane hydrate produced here is introduced into the dehydrator 20 and dehydrated in the same manner as described above.
[0043]
The methane hydrate whose water content has been reduced in the dehydrator 20 is cooled to a temperature at which it is not decomposed in the cooling device 21 even under atmospheric pressure, and is compacted into a shape suitable for storage and transportation in the compacting device 22. After being depressurized to atmospheric pressure at, it is packed into a dedicated storage tank 24.
[0044]
The gas hydrate packed in the storage tank 24 is loaded onto the transport ship 6 together with the storage tank 23 by the loading device 24 and transported toward the storage facility 7 on the ocean.
[0045]
Next, a second embodiment of the gas hydrate mining system according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component already demonstrated in the said 1st Embodiment, and description is abbreviate | omitted.
The gas hydrate mining system of the present embodiment is provided with a slurry manufacturing apparatus (slurry generating means) 30 that mixes the methane hydrate separated in the separator 10 and the water contained therein and processes it into a slurry form. Yes. The slurry production apparatus 30 is also supplied with methane hydrate from the generation apparatus 19.
[0046]
Furthermore, a concentration device (concentration means) 31 that separates water from the methane hydrate processed into a slurry to lower the water concentration in the slurry, and a concentration meter 32 that measures the concentration of the concentrated methane hydrate Is provided. The concentrator 32 is controlled by opening and closing a drain valve 33 a provided in the drain pipe 33 based on the methane hydrate concentration measured by the densitometer 32.
[0047]
The water separated from the concentrator 32 is saturated water rich in methane. Therefore, in the gas hydrate mining system of the present embodiment, the water tank connected to the drain pipe 33 as a gas recovery means for recovering the gas component contained in the methane saturated water separated from the methane hydrate in the concentrator 31. 34, a heater 35 that generates methane gas by heating methane saturated water in the water tank 34, and a gas pipe 36 that guides the methane gas in the water tank 34 to the generator 19. As a matter of course, the heat medium heated in the exhaust heat recovery heat exchanger 13 is used as the heat source of the heater 35.
[0048]
In the gas hydrate mining system configured as described above, the methane hydrate separated in the separation device 10 and the methane hydrate produced in the production device 19 are introduced into the slurry production device 30 to form a slurry. To be processed.
[0049]
The methane hydrate processed into the slurry is conveyed to the concentrating device 31 by the pump 37, and the water is separated and concentrated. The concentration of the concentrated methane hydrate is measured, and when the concentration is less than the predetermined concentration, the methane hydrate concentration is adjusted by controlling the opening degree of the drain valve 33a.
[0050]
Methane hydrate concentrated to an appropriate concentration is sent to the storage facility 7 through the pipeline PL laid between the platform 1 and the land storage facility 7.
[0051]
Next, a third embodiment of the gas hydrate mining system according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component already demonstrated in said each embodiment, and description is abbreviate | omitted.
The gas hydrate mining system of the present embodiment is provided with a heating device (hydrate heating means) 40 that heats the methane hydrate separated in the separation device 10 and the water contained therein to evaporate the water and gasify it. It has been. As the heat source of the heating device 40, the heat medium heated in the exhaust heat recovery heat exchanger 13 is naturally used.
[0052]
In the gas hydrate mining system configured as described above, the methane hydrate separated in the separation device 10 is introduced into the heating device 40 and heated to be gasified.
[0053]
The methane gas generated in the heating device 40 and the excess methane gas in the separation device 10 are sent to the storage facility 7 through the pipeline PL.
[0054]
【Effect of the invention】
As described above, according to the present invention, a part of the mined gas can be used as fuel for the driving means of the generator and the heat source in the facility, or the exhaust heat of the driving means can be used as the heat source in the facility. Thus, necessary electric power and heat energy can be procured without receiving external supply.
[0055]
According to the present invention, by dehydrating the obtained gas hydrate, the efficiency of transportation can be increased and the productivity can be improved.
[0056]
According to the present invention, by recovering the gas component in the gas saturated water separated from the gas hydrate by dehydration, the yield of underground resources can be increased and the productivity can be improved.
[0057]
According to the present invention, the mined gas hydrate is processed into a slurry state or gasified, so that it can be conveyed through the pipeline, and continuous resource supply can be performed.
[0058]
In the present invention, by recovering the gas component contained in the gas saturated water separated from the gas hydrate by concentration, the yield of underground resources can be increased and the productivity can be improved.
[0059]
In the present invention, by generating gas hydrate using surplus gas generated in the separation means as a raw material, the yield of underground resources can be increased and productivity can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment according to the present invention, and is a schematic diagram showing an offshore facility excavating methane hydrate and natural gas buried in seabed ground.
FIG. 2 is also a diagram illustrating the first embodiment, and is a diagram illustrating an overall outline of the system.
FIG. 3 is a diagram showing a second embodiment according to the present invention, and is a diagram showing an overall outline of the system.
FIG. 4 is a diagram showing a third embodiment according to the present invention, and is a diagram showing an overall outline of a system.
[Explanation of symbols]
2 Gas hydrate mining system 4 Hydrate piping 10 Separation device (separation means)
11 Generator 12 Motor (drive means)
13 Exhaust heat recovery heat exchanger 15 Combustor 18 Heat exchanger (fluid heating means)
20 Dehydrator 30 Slurry production device (slurry generating means)
31 Concentrator (concentration means)
32 Concentration meter 34 Water storage tank 40 Heating device (hydrate heating means)

Claims (12)

Separation means for separating at least gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator for generating power in the facility, and a part of the gas separated in the separation means as fuel And a heat recovery heat exchanger that recovers the exhaust heat of the drive means, and the fluid before being introduced into the separation means is heated by the heat recovered by the exhaust heat recovery heat exchanger. A gas hydrate mining system comprising: a fluid heating means . Separation means for separating at least gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator for generating power in the facility, and a part of the gas separated in the separation means as fuel A gas hydrate mining system comprising: a driving means for driving the gas ; and a dehydrating means for dehydrating the remaining fluid from which the gas has been separated. Separation means for separating at least gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator for generating power in the facility, and a part of the gas separated in the separation means as fuel and drive means for driving the water concentration of the slurry producing means, to separate the water from the produced slurry in a slurry in which the gas to form a slurry by kneading a gas hydrate and water remain after separation A gas hydrate mining system comprising: a concentrating means for lowering the concentration. Separation means for separating at least gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator for generating power in the facility, and a part of the gas separated in the separation means as fuel A gas hydrate mining system comprising: a driving means for driving the gas hydrate , and further comprising a hydrate heating means for heating the gas hydrate remaining after the gas is separated and evaporating moisture to gasify the gas hydrate. Separation means for separating at least gas from a fluid in a state where gas hydrate and gas and water are mixed, a generator for generating power in the facility, and a part of the gas separated in the separation means as fuel and drive means for driving a gas hydrate drilling system comprising: a generating means for generating a gas hydrate excess gas as a raw material. Gas hydrate drilling system of claim 1 or 5, wherein further comprising a dewatering means for dewatering the remainder of the fluid in which the gas has been separated. The gas hydrate mining system according to claim 2, further comprising a gas recovery unit that recovers a gas component contained in the water separated in the dehydration unit. A slurry generating means for kneading gas hydrate and water remaining after the gas is separated to form a slurry, and a concentrating means for separating water from the generated slurry to reduce the water concentration in the slurry. The gas hydrate mining system according to claim 1 or 5 . The gas hydrate mining system according to claim 3 or 8 , wherein the concentration of the slurry concentrated in the concentration means is detected, and the concentration means is controlled based on the detection result. The gas hydrate mining system according to any one of claims 3, 8 and 9, further comprising a gas recovery means for recovering a gas component contained in the water separated in the concentration means. Gas hydrate drilling system of claim 1 or 5, wherein further comprising a hydrate heating means said gases are gas hydrate is heated to evaporate water gasification which remains after separation. The gas hydrate mining system according to claim 4 or 11, wherein the hydrate heating means heats the gas hydrate using a heat source in the facility.

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