JP6047024B2 - Gas recovery system from gas hydrate layer and oil recovery system from oil sand layer - Google Patents

Description

  The present invention relates to a gas recovery system from a gas hydrate layer that recovers a flammable gas such as methane gas from a gas hydrate layer that exists in layers in the vicinity of the sea surface, underground, or near the surface of a cold region. The present invention can also be used for oil recovery from an oil sand layer.

  In general, natural gas often exists in a gas state in a gas layer existing in the ground, and can be recovered relatively easily by excavating the gas layer, and is widely used commercially.

For such conventional natural gas, there is a non-conventional natural gas that has not been established for recovery or is not commercially available due to low productivity.
Among such unconventional natural gas, gas hydrate is said to have the largest amount of resources. Gas hydrate is a kind of inclusion compound, and methane (CH ₄ ), ethane, which is a component of natural gas, is contained in a three-dimensional cage inclusion lattice formed by a plurality of water molecules (H ₂ O). A molecule such as (C ₂ H ₆ ) enters and has a comprehensive crystal structure.

Since this gas hydrate is filled with natural gas (methane gas or ethane gas) at a high density, the gas hydrate is theoretically converted to gas in the standard state in 1 m ^{3 of} gas hydrate. About 170 m ³ of natural gas is contained, and it has attracted a great deal of attention as a next-generation energy source.

  In addition, once gas hydrate is formed under the conditions of low temperature and high pressure, it can exist stably under the specific conditions. Therefore, even in the natural world, a layer is formed in the ground that meets these conditions. None exists. Such a gas hydrate layer is referred to as a “gas hydrate layer” or simply a “hydrate layer”.

  Since the gas hydrate exists under conditions of low temperature and high pressure as described above, the gas hydrate is decomposed and separated into gas and water by increasing the temperature or decreasing the pressure. For this reason, as a typical method for recovering gas from gas hydrate, hot water or the like is injected as heat energy into the gas hydrate layer existing in the seabed or underground ground, and the gas hydrate is gasified in the ground. There is known a method of separating the gas into water and recovering the gas to the surface in a gaseous state.

However, in order to decompose the gas hydrate and recover the gas, a temperature increase of several tens of degrees Celsius is required under the same pressure. Furthermore, taking into account the latent heat for melting ice, a lot of heat energy is required, and this hot water has to be supplied to the seabed at a depth of several hundreds of meters, usually where the gas hydrate layer exists. . In addition, since a large amount of hot water is supplied to the gas hydrate layer existing in the ground, the same amount of water as the supplied hot water must be collected together with gas from the seabed at a depth of several hundred meters. It needed a lot of power to pump up the water. In addition, when using electric power as a heat source for overheating, the electric power must be supplied to the seabed at a depth of several hundreds of meters, resulting in a large voltage drop and high energy efficiency even when using electric power. It was difficult to do.

  As with gas hydrate, oil sand is known as an alternative to petroleum fuel. However, oil recovery from the oil sand layer is more expensive than crude oil, and it can be used for disposal of waste soil. It has not been done so much because of the high cost.

  The gas recovery system according to Patent Document 1 addresses these problems, and is a gas recovery system from a gas hydrate layer that is highly energy efficient and does not require a large amount of water to be pumped and is profitable.

Japanese Patent No. 4707502

However, when trying to use the gas recovery system from the gas hydrate layer according to Patent Document 1 for a long period of time, the suction pipe of the thermal energy generator is clogged, or the filter (not shown) installed in the suction pipe is clogged, Gas recovery cannot be performed efficiently.
Moreover, in order to remove the clogging of the suction pipe and the filter, it is necessary to maintain the thermal energy generation device including the suction pipe and the filter (not shown). The thermal energy generation device is installed several hundred meters below the sea level. Therefore, it takes a great deal of cost and time to perform maintenance on the sea or on land.

  Patent Document 1 does not describe any oil recovery from the oil sand layer, but the gas recovery system described in Patent Document 1 can be used for oil recovery from the oil sand layer. The oil recovery from the same problem as the gas recovery from the gas hydrate layer exists.

Accordingly, a first object of the present invention is to eliminate the labor involved in maintenance required due to clogging of the suction pipe of the thermal energy generator or clogging of the filter, and stably recovering gas continuously for a long time. It is an object of the present invention to provide a gas recovery system from a gas hydrate layer that can perform the above.
In addition, the second object of the present invention is to eliminate the labor related to maintenance required due to clogging of the suction pipe of the thermal energy generator or clogging of the filter, and to recover oil stably continuously for a long time. It is an object of the present invention to provide an oil recovery system from an oil sand layer that can be used.

  In order to solve the above problems, the present invention is generated by disposing a thermal energy generator inside or near the gas hydrate layer and decomposing the gas hydrate with the thermal energy generated by the thermal energy generator. A gas recovery system for recovering gas from a gas hydrate layer, wherein the thermal energy generator includes a steam generator for heating the water to generate steam, and further heating the steam generated by the steam generator to overheat. Superheated steam generator that generates steam, and superheated steam generated by the superheated steam generator is jetted toward the gas hydrate layer as a high-speed air stream, or gas hydrate melted with the thermal energy of superheated steam at high speed A first pipe and a second pipe which are connected to each other and spatially continuous, and a part of which is recirculated to the superheated steam generator, The hot steam is jetted from the first pipe as a high-speed air stream toward the gas hydrate layer, and the gas hydrate melted by the thermal energy of the superheated steam is circulated by the high-speed air stream to form a circulating flow, part of which is 1st operation | movement which recirculates to a superheated steam production | generation apparatus from 2 pipe | tubes, and the gas hydrate which the superheated steam was jetted from the 2nd pipe | tube toward the gas hydrate layer as a high-speed air flow, and was fuse | melted with the thermal energy of superheated steam Is circulated by a high-speed air flow to form a circulating flow, and a control device that switches a second operation of returning a part of the flow from the first pipe to the superheated steam generating device is generated by the steam generating device. A gas characterized by switching the first operation and the second operation by switching the blowing direction of the superheated steam generated by the superheated steam generation device by switching the blown direction of the generated steam Providing a gas recovery system from Hydrate layer.

  The control device further includes a first filter that can be installed in the opening of the first tube and a second filter that can be installed in the opening of the second tube. The first filter is removed from the opening of the first tube, the second filter is installed in the opening of the second tube, and the second filter is opened from the opening of the second tube during the second operation. It is preferable to control the first filter and the second filter, respectively, so that the filter is removed and the first filter is installed in the opening of the first tube.

  In addition, the steam generator includes a water supply pipe for supplying water, a heater installed in the water supply pipe for heating the water supplied by the water supply pipe to generate steam, and an inclination toward the opening of the first pipe. A first steam supply pipe connected to the first pipe, a second steam supply pipe inclined to the opening of the second pipe and connected to the second pipe, and the first The apparatus further includes a first valve installed in the steam supply pipe and a second valve installed in the second steam supply pipe, and the control device opens the first valve and closes the second valve. Thus, the steam generated by the heater is blown out from the first steam supply pipe to the first pipe, the second valve is opened, and the first valve is closed to convert the steam generated by the heater into the second steam. It is preferable to blow out from the supply pipe to the second pipe and switch the direction of the blow out of the steam.

  Further, in the first operation, the control device installs the first filter in the opening of the first tube, removes the second filter from the opening of the second tube, and in the second operation, The first filter and the second filter are respectively controlled so that the second filter is installed at the opening of the second tube and the first filter is removed from the opening of the first tube. The second filter or the second filter can be backwashed.

  The first filter and the second filter are preferably wire filters.

  Further, a plurality of thermal energy generators are provided at predetermined intervals in the circumferential direction at the same position with respect to the axis of the gas recovery system, and the first filter is common to each of the openings of the plurality of first tubes. The installed second filter is preferably installed in common to each of the openings of the plurality of second tubes.

  The first valve and the second valve may be operated by the steam pressure generated by the steam generator.

  In addition, the present invention provides an oil sand that arranges a thermal energy generator in or near the oil sand layer, separates the oil from the oil sand by the thermal energy generated by the thermal energy generator, and collects the separated oil. An oil recovery system from a layer, wherein a thermal energy generator includes a steam generator for heating water to generate steam, and superheated steam generation for further heating the steam generated by the steam generator to generate superheated steam The superheated steam generated by the device and the superheated steam generator is ejected as a high-speed air stream toward the oil sand layer, or the oil separated by the thermal energy of the superheated steam is circulated by the high-speed air current to form a circulating flow, A part of the first and second pipes connected to each other and returning to the superheated steam generator and spatially continuous with the superheated steam as a high-speed air stream The oil separated from the heat energy of the superheated steam is circulated by a high-speed air flow to form a circulation flow, and a part of the oil is recirculated from the second pipe to the superheated steam generator. In the first operation, the superheated steam is jetted from the second pipe toward the oil sand layer as a high-speed air stream, and the oil separated by the thermal energy of the superheated steam is circulated in the high-speed air stream to form a circulating flow. And a control device that switches the second operation of returning the part from the first pipe to the superheated steam generation device, and the control device switches over the blowing direction of the steam generated by the steam generation device, thereby generating superheated steam. Provided is an oil recovery system from an oil sand layer, wherein a first operation and a second operation are switched by switching a jet direction of superheated steam generated by an apparatus.

  According to the present invention, the maintenance of the thermal energy generating device required due to clogging of the suction pipe or clogging of the filter can be omitted, and gas recovery from the gas hydrate layer and oil recovery from the oil sand layer are continuously performed for a long time. And can be performed stably.

It is a figure showing the schematic structure of the gas recovery system from the gas hydrate layer concerning one embodiment of the present invention. It is sectional drawing of the longitudinal direction which shows schematic structure of the hydrate decomposition | disassembly apparatus in the gas recovery system shown in FIG. It is a figure which shows the detailed structure of an example of the thermal energy generator in the hydrate decomposition | disassembly apparatus shown in FIG. It is operation | movement explanatory drawing which shows an example of the gas recovery operation | movement of the thermal energy generator shown in FIG. It is operation | movement explanatory drawing which shows the other example of gas recovery operation | movement of the thermal energy generator shown in FIG. It is operation | movement explanatory drawing which shows an example of the filter backwashing operation | movement of the thermal energy generator shown in FIG. It is operation | movement explanatory drawing which shows the other example of the filter backwashing operation | movement of the thermal energy generator shown in FIG. It is a figure which shows the detailed structure of the 1st modification of the thermal energy generator in the hydrate decomposition | disassembly apparatus shown in FIG. It is the sectional view on the AA line of the cylindrical heating apparatus in the thermal energy generator shown in FIG. It is a figure which shows the detailed structure of the 2nd modification of the thermal energy generator in the hydrate decomposition | disassembly apparatus shown in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing a schematic configuration of a gas recovery system 10 from a gas hydrate layer according to an embodiment of the present invention. FIG. 2 is a diagram of a hydrate decomposition apparatus 46 in the gas recovery system 10 shown in FIG. It is sectional drawing of the longitudinal direction which shows schematic structure.

  As shown in FIG. 1, the gas recovery system 10 from the gas hydrate layer according to the present embodiment is a multi-tubular structure that reaches a gas hydrate layer that exists in layers in the vicinity of the sea surface, underground or near the surface of a cold region. It has the structure of. Here, the case where the gas hydrate layer is present in a layered manner on the sea floor at a depth of several hundred meters below the sea surface, which is the most common form of the gas hydrate, will be described as an example.

  The gas recovery system 10 has a double structure of an outer cylinder 12 and an inner cylinder 14. The inside of the inner cylinder 14 is a gas recovery pipe 16 that recovers and conveys gas (methane gas or ethane gas) generated by decomposing gas hydrate, and the gap between the outer cylinder 12 and the inner cylinder 14 is Further, combustible gas and air supplied separately as heat sources from the outside, and a supply pipe 18 that supplies water that becomes superheated steam as a medium for heating the gas hydrate, and a conduction path 22 of a signal line 20 that transmits and receives signals. It has become.

The upper end of the gas recovery system 10 is connected to a structure 26 constructed on the sea surface 24 (or on the shore). Inside the structure 26, a combustible gas supply device 28, an air supply device 30, A water supply device 32, a gas tank 36, and a control device 34 are installed.
The combustible gas supply device 28, the air supply device 30 and the water supply device 32 supply the combustible gas, air and water through the supply pipe 18, and the control device 34 transmits and receives control signals through the signal line 20 to excavate. And control the combustion of combustible gas.

  In addition, the gas tank 36 is connected to the gas recovery pipe 16 and temporarily stores gas that has been separated and purified from moisture, mud, and gravel. The gas stored in the gas tank 36 is carried out by a pipeline and filled in a desired transport tank, or hydrated again and transported to the outside of the structure 26.

  In addition, a drilling device 38 is provided at the lower end (tip) of the gas recovery system 10. The drilling device 38 excavates and penetrates the upper formation 40 to form the upper formation 40 and the lower formation 42. A hydrate decomposition device 46 formed at the tip of the gas recovery system 10 is inserted into the gas hydrate layer 44 existing therebetween.

As shown in FIG. 2, the hydrate decomposition device 46 includes a thermal energy generation device 48, a thermal power generation device 50, and a gas recovery port 68 installed inside the multiple pipe of the gas recovery system 10.
The thermal energy generation device 48 includes a water supply pipe 56, a steam generation device 58, a superheated steam generation device 60, and a first filter 90 and a second filter 92, and the water supply pipe 56 is a second hand before the cylindrical member. And is connected to the cylindrical member by the first steam supply pipe 64A and the second steam supply pipe 64B. In addition, the steam generator 58 includes a first electromagnetic unit installed in each of the heater 62 installed before the branch of the water supply pipe 56 and the first steam supply pipe 64A and the second steam supply pipe 64B after branching. It consists of a valve 63A and a second electromagnetic valve 63B . The superheated steam generation device 60 includes a cylindrical member made up of the first tube 52 and the second tube 54 and a high-frequency heating device 66 installed in each of the first tube 52 and the second tube 54. . The first filter 90 and the second filter 92 are movably installed in the opening of the first tube 52 and the opening of the second tube 54 inside the outer cylinder 12. The

The water supply pipe 56 supplies water for steam generation to the steam generator 58. The water is heated by the heater 62 installed in front of the branch through the water supply pipe 56 to become steam, and the first steam supply pipe 64A or the second steam supply pipe connected to the cylindrical member at an inclination. From 64B, it is ejected to the 1st pipe | tube 52 or the 2nd pipe | tube 54 of a cylindrical member.
The heater 62 of the steam generator 58 heats the water passing through the water supply pipe 56 into steam, and jets the steam to the first steam supply pipe 64A or the second steam supply pipe 64B. The first electromagnetic valve 63A and the second electromagnetic valve 63B of the steam generating device 58 are configured to switch either the first electromagnetic valve 63A or the second electromagnetic valve 63B based on the control signal from the control device 34 described above. Open and close the other. The steam is jetted into the cylindrical member 61 from the open steam supply pipe.

  The tubular member 61 of the superheated steam generator 60 is constituted by a first tube 52 and a second tube 54, and the first tube 52 and the second tube 54 are inclined toward the gas hydrate layer, respectively. Open. Further, the first steam supply pipe 64A is connected to the first pipe 52 and is inclined and opened in the direction of the first pipe 52. Similarly, the second steam supply pipe 64B It is connected to the tube 54 and is opened inclining in the direction of the second tube 54.

As shown in detail in FIG. 3, the first tube 52 includes a first steam valve 65A, and the second tube 54 includes a second steam valve 65B. The first steam valve 65A is moved by the steam ejected by opening the first electromagnetic valve 63A to open the opening of the first steam supply pipe 64A, and the second steam valve 65B is The opening of the second steam supply pipe 64B is closed by being moved by the steam ejected by opening the first electromagnetic valve 63A. Further, the first steam valve 65A is moved by the steam ejected by opening the first electromagnetic valve 63B to close the opening of the first steam supply pipe 64A, and the second steam valve 65B is When the first electromagnetic valve 63B is opened, the first electromagnetic valve 63B is moved by the jetted steam to open the opening of the second steam supply pipe 64B. Note that the first steam valve 65A and the second steam valve 65B are not supplied with steam from either the first electromagnetic valve 63A or the second electromagnetic valve 63B, for example, a spring (not shown) or the like. Due to the elastic force, the first steam supply pipe 64A and the second steam supply pipe 64B operate so as to close the respective openings.

  Further, the high-frequency heating device 66 of the superheated steam generation device 60 is disposed around the first tube 52 and the second tube 54, respectively, and has a cylindrical shape from the first steam supply tube 64A or the second steam supply tube 64B. The steam ejected into the member 61 is further heated to generate superheated steam. In addition, as a high frequency electromagnetic wave used here, a thing with a frequency of about several hundred megahertz-dozens of terahertz is used suitably. In particular, the terahertz class has the effect of promoting the decomposition of gas hydrate by penetrating deeply into the inside of gas hydrate and electromagnetic waves of frequencies (generally hundreds to thousands of megahertz) used for the decomposition of gas hydrate. It is also effective to use an appropriate combination with electromagnetic waves having the above frequency.

The first filter 90 and the second filter 92 are movable inside the outer cylinder 12 so as to cover the opening of the first tube 52 and the opening of the second tube 54 of the cylindrical member, respectively. It is installed and operates according to a control signal from the control device 34. When superheated steam is ejected from the first pipe 52 toward the hydrate layer, the first filter 90 is removed from the opening of the first pipe 52, and the second filter 92 is connected to the second pipe 54. Installed in the opening. When superheated steam is ejected from the second pipe 54 toward the hydrate layer, the second filter 92 is removed from the opening of the second pipe 54, and the first filter 90 is connected to the first pipe 90. 52 at the opening.
The first filter 90 and the second filter 92 may be configured by, for example, cylindrical wire filters along the inner peripheral surface of the outer cylinder 12 of the gas recovery system 10. In addition, the first filter 90 and the second filter 92 may be moved up and down by, for example, a motor supplied with power by the power generation device 50, and the first steam valve 65A and the second steam Similarly to the valve 65B, the valve 65B may move up and down depending on the vapor pressure.

The thermal power generator 50 includes a combustible gas supply pipe 70, an air supply pipe 72, a combustion chamber 74, a burner 76, a turbine 78, a generator including a rotor 80 and a stator 82, a rotating shaft 84, and an exhaust path 86. It is comprised by.
The combustible gas supply pipe 70 and the air supply pipe 72 supply the combustible gas and air to the combustion chamber 74 independently from the outside.
In the combustion chamber 74, the combustible gas and air supplied from the combustible gas supply pipe 70 and the air supply pipe 72 are mixed and burned by the burner 76 installed in front of the combustion chamber 74, and combustion gas is generated.
The turbine 78 is connected to the rotor 80 of the generator by a rotating shaft 84 rotatably supported by a bearing device (not shown), and is installed behind the combustion chamber 74 to supply high-speed fuel gas. It rotates at high speed.

The generator includes a rotatable rotor 80 and a stator 82, and power is generated by the rotor 80 rotating with respect to the stator 82.
Since the rotor 80 is connected by the turbine 78 and the rotating shaft 84, the rotor 78 is rotated by the rotation of the turbine 78. The stator 82 receives the rotation of the rotor 80 to generate electric power, and the heater 62 of the steam generator 58, the first electromagnetic valve 63A and the second electromagnetic valve 63B, the high-frequency heating device 66 of the superheated steam generator 60, and the like. To supply power.

  The exhaust path 86 exhausts the combustion gas burned in the combustion chamber 74 to the outside. In the present embodiment, the turbine 78 is rotated again as a waste heat turbine in the middle of the exhaust path 86 to increase the power generation efficiency. In addition, the exhaust passage 86 heats the surrounding gas hydrate layer by returning to the outer peripheral portion of the gas recovery system 10, and refluxes the outside of the water supply pipe 56 to freeze the water in the water supply pipe 56. To prevent. The exhaust path 86 may include a blower (not shown) that creates a flow in the exhaust direction. By creating a flow in the exhaust direction with the blower, exhaust can be performed smoothly. The exhaust path 86 is connected to, for example, an opening (not shown) installed in the outer cylinder 12, and the exhaust gas cooled through the exhaust path 86 may be exhausted into the sea or the like through an opening (not shown). In addition, the opening part which is not illustrated opens in the sea etc., preventing intrusion of seawater etc. in the case of exhaust_gas | exhaustion.

  The gas recovery port 68 recovers the gas hydrate (gas) that has been heated by the heat energy of the superheated steam and has melted and flowed, and transports it to the gas recovery pipe 16. The gas recovery port 68 is provided with a strainer and a filter (not shown) so that foreign matter such as earth and sand and gravel does not enter during gas recovery.

Next, the gas recovery operation of the gas recovery system 10 according to the present embodiment will be described.
The gas recovery system 10 digs up the upper formation 40 in the sea by a drilling device 38 installed at the tip of the gas recovery system 10, and the inside of the gas hydrate layer 44 existing between the upper formation 40 and the lower formation 44 in the sea. Then, the hydrate decomposition device 46 is installed inside the gas hydrate layer 44.
During excavation, the thermal energy generating device 48 of the hydrate decomposition device 46 closes the first electromagnetic valve 63A and the second electromagnetic valve 63B, and the first steam valve 65A and the second steam valve. Since no steam is supplied to any of 65B, as described above, as shown in FIG. 3, the first steam valve 65A installed in the first pipe 52 of the cylindrical member is the first steam supply. The pipe 64A is closed, and the second steam valve 65B installed in the second pipe 54 closes the second steam supply pipe 64B. In addition, the first filter 90 is installed at the opening of the first tube 52, and the second filter 92 is installed at the opening of the second tube 54. By installing the first filter 90 and the second filter 92 in the respective openings of the first tube 52 and the second tube 54, the first filter 90 and the second filter 92 are placed inside the first tube 52 and the second tube 54. By preventing dirt and sand and gravel from entering, and the first steam valve 65A and the second steam valve 65B close each of the first steam supply pipe 64A and the second steam supply pipe 64B, such as water to each of the first steam supply pipe 64A and the second steam supply pipe 64B is prevented from flowing back.

As shown in FIG. 4, the thermal energy generating device 48 of the hydrate decomposition device 46 receives the control signal for gas hydrate recovery from the control device, opens the first electromagnetic valve 63A, and the second electromagnetic valve 63B. Is closed, and the steam heated by the heater 62 is supplied to the first electromagnetic valve 63A side. The steam is ejected through the first electromagnetic valve 63A, opens the first steam valve 65A, closes the second steam valve 65B, and enters the first pipe 52 from the first steam supply pipe 64A. Is erupted. The jetted steam is further heated to superheated steam by a high-frequency heating device 66 installed around the first pipe 52, and becomes a high-speed air stream to form gas hydrate from the opening of the first pipe 52. Spouted toward the bed, the surrounding gas hydrate is heated and separated into gas and water. The high-speed air flow ejected toward the gas hydrate layer becomes a circulation flow containing gas, water, and steam, and a part of the circulation flow is the first installed in front of the opening of the second pipe 54. The flow returns to the second pipe 54 through the second filter 92. This reflux is superheated again by the high-frequency heating device 66 installed around the first pipe 52 together with the steam supplied from the first steam supply pipe 64 </ b> A, and is ejected from the opening of the first pipe 52 again. The Since the second steam supply pipe 64B is closed by the second steam valve 65B, the reflux does not flow back through the second steam supply pipe 64B.

Moreover, the thermal energy generator 48 of the hydrate decomposition apparatus 46 can switch the direction of the circulating flow that decomposes the gas hydrate layer. When the second filter 92 is clogged and the circulation flow cannot be generated well in the above-described direction, the thermal energy generator 48 sends a control signal for gas hydrate recovery from the controller as shown in FIG. In response, the second electromagnetic valve 63B is opened and the first electromagnetic valve 63A is closed, whereby the steam heated by the heater 62 is supplied to the first electromagnetic valve 63B side. The steam is ejected through the second electromagnetic valve 63B, opens the second steam valve 65B, closes the first steam valve 65A, and enters the second pipe 54 from the second steam supply pipe 64B. Is erupted. The jetted steam is further heated to superheated steam by a high-frequency heating device 66 installed around the second pipe 54, and becomes a high-speed air stream to form a gas hydrate from the opening of the second pipe 54. Spouted toward the bed, the surrounding gas hydrate is heated and separated into gas and water. The high-speed airflow ejected toward the gas hydrate layer becomes a circulation flow containing gas, water, and steam, and part of the circulation flow is the first installed in front of the opening of the first pipe 52. The flow returns to the first pipe 52 through the first filter 90. The reflux is superheated again by the high-frequency heating device 66 installed around the second pipe 54 together with the steam supplied from the second steam supply pipe 64B, and is ejected from the opening of the second pipe 54 again. The In addition, since the first steam supply pipe 64A is closed by the first steam valve 65A, the reflux does not flow back through the first steam supply pipe 64A.

The gas recovery port 68 recovers the gas from the circulating flow of the gas hydrate heated by the heat energy of the superheated steam and flowing in the molten state, and conveys the recovered gas to the gas recovery pipe 16. Since the gas recovery port 68 is provided with a strainer and a filter, water and impurities are removed and only the gas is recovered in the gas recovery pipe 16.
The above is the gas recovery operation of the gas recovery system 10 according to the present embodiment.
By switching the direction of the circulation flow of the gas hydrate, even if one filter is clogged, gas recovery can be continued using the other filter.

Next, the backwashing operation of the filter of the gas recovery system 10 according to the present embodiment will be described.
It has been found that the first filter 90 or the second filter 92 is clogged when the flow rate of the circulating flow measured by an unillustrated current meter or the like does not exceed a predetermined value or after a long period of use. In this case, the control device 34 instructs the thermal energy generation device 48 of the hydrate decomposition device 46 to backwash the filter.

When it is determined that the second filter 92 is clogged, as shown in FIG. 6, the thermal energy generator 48 receives the control signal from the controller 34 and moves the second filter 92 to the second filter 92. Further, the first electromagnetic valve 63A is closed and the second electromagnetic valve 63B is opened, and the steam heated by the heater 62 is moved to the second electromagnetic valve 63B side. Supply.
The steam is ejected through the second electromagnetic valve 63B, opens the second steam valve 65B, closes the first steam valve 65A, and enters the second pipe 54 from the second steam supply pipe 64B. Is erupted. The ejected steam was further heated to superheated steam by a high-frequency heating device 66 installed around the second pipe 54, and was installed at the opening of the second pipe 54 as a high-speed air stream. The second filter 92 is backwashed. The high-speed airflow passes through the second filter 92 in the reverse direction, so that the second filter 92 is vibrated, and dirt such as gravel clogged in the eyes of the second filter 92 is further removed from the outside of the second tube 54. Sifts to the outside of the outer cylinder 12.

When it is determined that the first filter 90 is clogged, the thermal energy generator 48 receives the control signal from the controller 34 and turns the first filter 90 on as shown in FIG. It arrange | positions in the front surface of the opening part of the 1st pipe | tube 52, and also the 2nd electromagnetic valve 63B is closed, the 1st electromagnetic valve 63A is open | released, and the vapor | steam heated by the heater 62 is 1st electromagnetic valve 63A. Supply to the side.
The steam is ejected through the first electromagnetic valve 63A, opens the first steam valve 65A, closes the second steam valve 65B, and enters the first pipe 52 from the first steam supply pipe 64A. Is erupted. The ejected steam was further heated to superheated steam by a high-frequency heating device 66 installed around the first pipe 52, and was installed at the opening of the first pipe 52 as a high-speed air stream. The first filter 90 is backwashed. The high-speed airflow passes through the first filter 90 in the reverse direction, so that the first filter 90 is vibrated, and dust such as gravel clogged in the eyes of the first filter 90 is further removed outside the first pipe 52. Sifts to the outside of the outer cylinder 12.
The above is the backwashing operation of the filter of the gas recovery system 10 according to the present embodiment.
By regularly backwashing the filter, it is possible to prevent a reduction in gas recovery efficiency due to clogging of the filter and to recover gas stably for a long period of time.

The thermal energy generation device 48 of the gas recovery system 10 according to the present invention does not include the first filter 90 and the second filter 92 in the respective openings of the first tube 52 and the second tube 54. May be.
Even if a filter is not installed in the openings of the first tube 52 and the second tube 54, a circulating flow can be generated, and the first tube 52 or the second tube 54 can be provided without a filter. However, the clogging of the pipe can be removed by reversing the direction of the circulation flow.

  The gas recovery system 10 according to the present invention further includes at least one for adjusting the recovered gas pressure in the gas recovery path including the gas recovery pipe 16 between the ground or the sea and the gas hydrate layer. It is preferable to have two pressure adjusting means.

  Further, in the gas recovery path including the gas recovery pipe 16, it is preferable to have at least one conversion means for converting the recovered gas between the ground or the sea and the gas hydrate layer. Here, the gas conversion is, for example, a step of removing impurities in methane gas (actually, a mixed gas containing methane as a main component) obtained as a result of thermal decomposition of methane hydrate, or a step of removing moisture. Furthermore, although the process etc. which change methane gas to methanol by adding oxygen using a catalyst are used suitably, it is not limited to these.

  In addition, the combustible gas used in the power generation apparatus 50 needs to be supplied from the outside at the beginning, but after the gas recovery from the gas hydrate gets on track, a part of the recovered gas is used. Can be changed.

  Incidentally, it is effective to generate cracks in the gas hydrate layer in order to efficiently recover the gas by the decomposition of the gas hydrate using the circulating flow as described above. As a method of generating cracks in such a gas hydrate layer, it is effective to generate strain by locally heating and expanding the gas hydrate layer, but in addition to that, giving an impact Therefore, it is also effective to generate cracks mechanically. The method of giving an impact is not particularly limited, but in general, it is not a method using mechanical vibration, but a non-contact method in which a shock wave or the like is generated and this is applied to a gas hydrate layer to generate a crack. Is easy to use and effective.

As a shock wave generating device that can be used here, there are various known methods such as a spark discharge method, a piezo effect method, an electromagnetic conversion method, and an electrohydraulic method. Any method may be used as long as the above can be obtained.
In the case of actually applying a shock wave, it is preferable to further apply a shock wave to the hydrate layer while irradiating the hydrate layer with ultrasonic waves or microwaves.

  The gas recovery system 10 according to this embodiment generates cracks in the hydrate layer by applying a shock wave, and improves the hydrate decomposition efficiency by causing the cracks to function as a base for hydrate decomposition. As long as this object is achieved, a shock wave generated by an arbitrary method can be applied by an arbitrary method (continuous or intermittent).

In the above-described embodiment, the first steam supply pipe 64A and the second steam supply pipe 64B are gate valves (slides) that are closed by sliding the first steam valve 65A and the second steam valve 65B, respectively. Valve), the first steam valve 65A and the second steam valve 65B can be used as the gate valves if the backflow to the first steam supply pipe 64A and the second steam supply pipe 64B can be prevented. Instead, for example, it may be configured by a butterfly valve, may be configured by a ball valve, may be configured by a globe valve, may be configured by a check valve, a needle valve, a piston valve, etc. It may be constituted by. As described above, various known valves can be used. The first steam valve 65A and the second steam valve 65B are not only closed by simply sliding, but also not only closed by simply rotating, but also, for example, sliding while rotating. Thus, each of the first steam supply pipe 64A and the second steam supply pipe 64B can be more reliably closed.
Similarly, the above-described various known valves can be used for the first electromagnetic valve 63A and the second electromagnetic valve 63B.

  The hydrate decomposition device 46 includes a steam generator 58, a superheated steam generator 60 and a thermal energy generator 48 including a tubular member 61, a combustion chamber 74, a turbine 78, a rotating shaft 84, a rotor, and a stator. A power generator 50 composed of a generator forms a set, and it is preferable that a plurality of sets of the hydrate decomposition apparatuses 46 are arranged at appropriate intervals along the gas recovery system 10. By installing a plurality of gasses in this way, gas recovery at a plurality of locations is performed by one gas recovery system 10, and a larger amount of gas can be recovered efficiently.

Further, a plurality of units including the energy generation device 48 and the power generation device 50 may be provided in the same position on the axis of the gas recovery system 10 and in the circumferential direction of the outer cylinder 12. In this case, it is preferable that the combustion gas supply pipe and the water supply pipe inside the unit can be used independently for each unit. The first filter 90 is installed in common in the openings of the plurality of first tubes 52, and the second filter 92 is installed in common in the openings of the plurality of second tubes 54. It is preferable.
By providing the above-described configuration, the surrounding gas hydrate can be efficiently decomposed without complicating the configuration of the gas recovery system 10.

(First Modification of Thermal Energy Generator)
As a first modification of the thermal energy generating device according to the present invention, as shown in FIG. 8, the first tube 152 and the second tube 154 include a cylindrical heating device 169 on the outside thereof. Also good. Since the first tube 152 and the second tube 154 are vertically symmetrical , only the first tube 152 side is shown in FIG.
FIG. 9 is a cross-sectional view taken along line AA of the cylindrical superheater 169 shown in FIG. As shown in FIGS. 8 and 9, the cylindrical heating device 169 includes a cylindrical combustible gas supply pipe 170 and a cylindrical air supply pipe 172, a cylindrical combustion chamber 174, a cylindrical burner 176, and It consists of a cylindrical exhaust passage 186. A cylindrical combustible gas supply pipe 170 and a cylindrical pipe are provided outside the center where the first pipe 152 and the second pipe 154 are connected to each other, and cover the periphery of the first pipe 152 and the second pipe 154, respectively. Air supply pipes 172 are respectively installed, and combustion chambers 174 are respectively installed at the ends thereof.

Combustible gas and air are supplied from the cylindrical combustible gas supply pipe 170 and the cylindrical air supply pipe 172, and are ignited by the burner 176, whereby combustion occurs in the combustion chamber 174, and the first pipe 152 and the first pipe The circumference of the second tube 154 is heated. The first pipe 152 and the second pipe 154 are heated by the combustion chamber 174 to heat the steam supplied to the first pipe 152 and the second pipe 154 together with the high-frequency heating device 66, and superheated steam. And The exhaust path 186 is installed so as to cover the cylindrical combustion chamber 174, the cylindrical combustible gas supply pipe 170, and the cylindrical air supply pipe 172, thereby preventing the temperature of these portions from decreasing. , Make effective use of waste heat. The exhaust passage 186 may further include a blower (blower) (not shown). By creating an air flow in the exhaust direction by the blower, quick combustion and exhaust are possible. Similarly to the exhaust path 86, the exhaust path 186 is connected to, for example, an opening (not shown) installed in the outer cylinder 12, and the exhaust gas cooled through the exhaust path 186 passes through the opening (not shown) into the sea or the like. It may be exhausted. In addition, the opening part which is not illustrated opens in the sea etc., preventing intrusion of seawater etc. in the case of exhaust_gas | exhaustion.
As shown in FIG. 8, the cylindrical heating device 169 may be installed in front of the high-frequency heating device 66, or may be installed at substantially the same position as the high-frequency heating device 66. It may be installed behind.

The above-described cylindrical heating device 169 is not limited to the first tube 152 and the second tube 154, and may be installed in the gas recovery tube 16 at a predetermined interval as in the case of the thermal power generation device 50. It may be installed in the mouth 168.
Since the gas is recovered from the gas hydrate layer under a low temperature and a high pressure , the gas may be cooled and immediately return to the gas hydrate. Moreover, the water supplied by the water supply pipe 56 is also easily frozen in the middle of the water supply pipe. Therefore, in the gas recovery system 10, by installing the cylindrical heating device 169 and the thermal power generation device 50 at predetermined intervals, the recovered gas can be prevented from becoming gas hydrate and freezing of water.

Further, as shown in FIG. 8, a plurality of gas recovery ports 168 may be installed in the vicinity of the openings of the first tube 152 and the second tube 154 of the thermal energy generator 148.
Even if the gas hydrate is gasified by the thermal energy generator 148, the gas is immediately deprived of heat and returned to the gas hydrate when the temperature is increased and the temperature is increased such as at the sea bottom. Therefore, the closer the installation position of the thermal energy generator 148 and the installation position of the gas recovery port 168 are, the more efficiently the gasified gas hydrate can be recovered.
At that time, the first filter 90 and the second filter 92 may also serve as one of a plurality of filters installed in the gas recovery port 168.

(Second Modification of Thermal Energy Generator)
Further, as a second modification of the thermal energy generating device according to the present invention, as shown in FIG. 10, the first tube 252 and the second tube 254 of the thermal energy generating device 248 may have a spiral shape. Good. Similar to the first modification of the thermal energy generation device, the first tube 252 and the second tube 254 may include a cylindrical heating device 269 on the outside thereof. The cylindrical heating device 269 has the same configuration as that of the first modification.
The first tube 252 and the second tube 254 are each provided with a spiral shape, so that the steam and the circulation flow through the first tube 252 and the second tube 254 are warmed for a longer time, and the gas hydrate layer is formed. The heat energy can be supplied more reliably.

  As mentioned above, although the gas recovery system from the gas hydrate layer of the present invention has been described in detail, the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the gist of the present invention. Changes may be made.

  The gas recovery system of the present invention can be used not only for gas recovery from the gas hydrate layer but also for oil recovery from the oil sand layer. An oil recovery system having the same configuration as the gas recovery system of the present invention is installed in the oil sand layer, and high pressure superheated steam is injected into the oil sand layer from the thermal energy generator to separate the oil from the oil sand layer. It can be recovered.

  10 gas recovery system, 12 outer cylinder, 14 inner cylinder, 16 gas recovery pipe, 18 supply pipe, 20 signal line, 22 conduction path, 24 sea surface, 26 structure, 28 combustible gas supply apparatus, 30 air supply apparatus, 32 water Supply device, 34 control device, 36 gas tank, 38 drilling device, 40, 42 formation, 44 gas hydrate layer, 46 hydrate decomposition device, 48, 148, 248 thermal energy generation device, 50 thermal power generation device, 52, 152, 252 first pipe, 54, 154, 254 second pipe, 56 water supply pipe, 58 steam generator, 60 superheated steam generator, 61 cylindrical member, 62 heater, 63A first electromagnetic valve, 63B second Solenoid valve, 64A first steam supply pipe, 64B second steam supply pipe, 65A 1 steam valve, 65B second steam valve, 66 high frequency heating device, 68, 168 gas recovery port, 169, 269 cylindrical heating device, 70, 170 combustible gas supply pipe, 72, 172 air supply pipe, 74, 174 Combustion chamber, 76, 176 burner, 78 turbine, 80 rotor, 82 stator, 84 rotating shaft, 86, 186 exhaust path, 90 first filter, 92 second filter.

Claims (8)

Gas recovery from the gas hydrate layer that disposes the gas hydrate by recovering the gas hydrate by disposing the gas hydrate with the thermal energy generated in the thermal energy generator, placing the thermal energy generator in or near the gas hydrate layer A system,
The thermal energy generator is
A steam generator for heating water to generate steam;
A superheated steam generator for further heating the steam generated by the steam generator to generate superheated steam;
The superheated steam generated by the superheated steam generator is jetted toward the gas hydrate layer as a high-speed air stream, or the gas hydrate melted by the thermal energy of the superheated steam is circulated in the high-speed air stream. A first stream and a second pipe connected to each other and spatially continuous, a part of which is recirculated to the superheated steam generator,
The superheated steam is jetted from the first pipe as the high-speed air stream toward the gas hydrate layer, and the gas hydrate melted by the thermal energy of the superheated steam is circulated by the high-speed air stream to form a circulating flow. , A first operation of returning a part of the superheated steam from the second pipe to the superheated steam generator, and jetting the superheated steam from the second pipe as the high-speed air stream toward the gas hydrate layer. A second operation of circulating a gas hydrate melted by the thermal energy of the superheated steam with the high-speed air flow to form a circulating flow, and returning a part of the gas hydrate from the first pipe to the superheated steam generation device. A control device for switching,
The control device switches the blowing direction of the superheated steam generated by the superheated steam generating device by switching the blowing direction of the steam generated by the steam generating device, and the first operation and the first 2. A gas recovery system from a gas hydrate layer, wherein the operation is switched between two operations. A first filter that can be installed in the opening of the first tube, and a second filter that can be installed in the opening of the second tube;
In the first operation, the control device removes the first filter from the opening of the first tube, installs the second filter in the opening of the second tube, and In the second operation, the first filter is removed so that the second filter is removed from the opening of the second tube, and the first filter is installed in the opening of the first tube. The gas recovery system from a gas hydrate layer according to claim 1, wherein the second filter and the second filter are controlled. The steam generator is
A water supply pipe for supplying water;
A heater installed in the water supply pipe, for heating the water supplied by the water supply pipe to generate steam;
A first steam supply pipe inclined to the opening of the first pipe and connected to the first pipe;
A second steam supply pipe inclined to the opening of the second pipe and connected to the second pipe;
A first valve installed in the first steam supply pipe;
A second valve installed in the second steam supply pipe,
The controller is
By opening the first valve and closing the second valve, the steam generated by the heater is blown out from the first steam supply pipe to the first pipe, and the second valve is opened. The steam generated by the heater is blown out from the second steam supply pipe to the second pipe by closing the first valve, and the blowing direction of the steam is switched. Or the gas recovery system from the gas hydrate layer of 2.   In the first operation, the control device installs the first filter in the opening of the first tube, removes the second filter from the opening of the second tube, and In the operation, the first filter and the second filter are installed so that the second filter is installed in the opening of the second tube, and the first filter is removed from the opening of the first tube. The gas recovery system from a gas hydrate layer according to claim 2 or 3, wherein the first filter or the second filter is back-washed by controlling each of the filters.   The gas recovery system from a gas hydrate layer according to any one of claims 2 to 4, wherein the first filter and the second filter are wire filters. A plurality of the thermal energy generators are provided at predetermined intervals in the circumferential direction at the same position with respect to the axis of the gas recovery system,
The first filter is commonly installed in each of the openings of the plurality of first tubes, and the second filter is commonly installed in each of the openings of the plurality of second tubes. The gas recovery system from a gas hydrate layer according to any one of claims 2 to 5, wherein   4. The gas recovery system from a gas hydrate layer according to claim 3, wherein the first valve and the second valve are operated by a vapor pressure generated by the steam generator. 5. An oil recovery system from an oil sand layer that arranges a thermal energy generator inside or near the oil sand layer, separates the oil from the oil sand by the thermal energy generated by the thermal energy generator, and recovers the separated oil Because
The thermal energy generator is
A steam generator for heating water to generate steam;
A superheated steam generator for further heating the steam generated by the steam generator to generate superheated steam;
The superheated steam generated by the superheated steam generation device is jetted toward the oil sand layer as a high-speed air flow, or the oil separated by the thermal energy of the superheated steam is circulated by the high-speed air flow to form a circulating flow. A first pipe and a second pipe connected to each other and spatially recirculating a part thereof to the superheated steam generator;
The superheated steam is jetted from the first pipe as the high-speed air stream toward the oil sand layer, and the oil separated by the thermal energy of the superheated steam is circulated by the high-speed air stream to form a circulating flow. A first operation for recirculating a part from the second pipe to the superheated steam generator, and the superheated steam is jetted from the second pipe toward the oil sand layer as the high-speed air stream, A control device for switching the second operation of circulating the oil separated by the heat energy of the high-speed air flow into a circulating flow and returning a part of the oil to the superheated steam generator from the first pipe ,
The control device switches the blowing direction of the superheated steam generated by the superheated steam generating device by switching the blowing direction of the steam generated by the steam generating device, and the first operation and the first 2. An oil recovery system from an oil sand layer, characterized in that the operation of 2 is switched.

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