CN105863575B - Submarine natural gas collection device and method heated by circulating hot water pipeline with built-in buoyancy tank - Google Patents

Abstract

The invention discloses a seabed natural gas collection device and method heated by a circulating hot water pipeline with a built-in floating tank, and belongs to the technical field of natural gas collection. The invention comprises a mother ship and an inner hollow natural gas collection cover. The natural gas collection and storage device is provided on the mother ship. The natural gas storage and storage device is connected to the top of the natural gas collection cover through a gas production pipeline, and the natural gas collection cover is connected to the mother ship through a water riser At the bottom, the gas production pipeline is arranged in the water riser; the bottom of the natural gas collection cover is provided with an anchor system, a pressure regulation system is provided at the bottom of the natural gas collection cover, and a propulsion system is provided on the outer wall of the natural gas collection cover. The side wall of the natural gas collection hood is provided with a density adjustment system, and the inside of the natural gas collection hood is provided with a temperature adjustment system and an agitation system. The invention mainly solves the problem that the gas hydrate in the seabed mud bed will not form the escape and leakage of natural gas during the process of decomposing, collecting and exploiting.

Description

Submarine natural gas collection device and method heated by circulating hot water pipeline with built-in buoyancy tank

technical field

The invention relates to the technical field of natural gas collection, in particular to the seabed natural gas hydrate collection technology.

Background technique

Submarine natural gas hydrate is a crystal formed by the combination of methane gas and water molecules in the low-temperature and high-pressure environment of the seabed. It is a clean energy with huge reserves, and it is expected to replace oil and coal as the main energy source. Gas hydrates are widely distributed in seabed sediments, and have the characteristics of large reserves, weak cementation, and poor stability. Once the temperature and pressure conditions in the area change, it may cause a large amount of decomposition, gasification and free release of seabed gas hydrates.

Since natural gas hydrate is mainly decomposed into methane gas and water, however, methane gas is a greenhouse gas, and a large amount of release into the atmosphere will cause the greenhouse effect and cause serious damage to the environment. How to ensure that natural gas does not leak or escape during the exploitation of seabed natural gas hydrate and how to efficiently decompose natural gas hydrate are the main research directions for the development of seabed natural gas hydrate deposits.

In the existing natural gas hydrate mining technology, the natural gas hydrate deposits on the seabed are usually converted into gas and water by depressurization method, heat injection method or chemical reagent injection method, etc., the converted gas is collected, and then passed Underwater production facilities or floating production facilities are used for production. At present, there is no mature method and system for the exploitation of subsea natural gas hydrate that has been officially put into commercial operation. The United States, Japan and other countries are all conducting experimental exploitation.

The main reason is that the existing mining methods are relatively complicated, costly, and lack of controllability and operability, which may easily cause leakage of methane gas, cause environmental pollution and atmospheric greenhouse effect, and the mining efficiency cannot meet the minimum requirements for industrial development. , are still in the stage of laboratory exploration and cannot be put into commercial operation. Therefore, there is a need for an environmentally friendly, economical and efficient exploitation system to realize the exploitation of seabed natural gas hydrate.

Contents of the invention

The purpose of the present invention is to: aim at the above existing problems, to provide a seabed natural gas collection device and method with a built-in buoyancy tank circulating hot water pipeline heating, which mainly solves the problem of natural gas hydrate in the seabed mud bed in the process of decomposing, collecting and exploiting In the process, the problem of escape and leakage of natural gas will not be formed. The present invention breaks through the conventional thinking mode and cleverly uses pressure regulation to form negative pressure and temperature regulation system to increase temperature to promote the decomposition of natural gas hydrate in the seabed mud bed, which is beneficial to the seabed. The exploitation of natural gas hydrate, then greatly improves the collection rate of natural gas, provides a new direction for the exploitation of seabed natural gas hydrate; It can be seen that the present invention can ensure stable production through the control of density, pressure and temperature, and the collection of natural gas is convenient and convenient. High efficiency and can be reused many times.

The technical scheme that the present invention adopts is as follows:

The submarine natural gas collection device with built-in buoyancy tank circulating hot water pipeline heating of the present invention includes a mother ship and an inner hollow natural gas collection cover, the mother ship is provided with a natural gas collection and storage device, and the natural gas storage and storage device is connected to natural gas through a gas production pipeline The top of the collection cover, the natural gas collection cover is connected to the bottom of the mother ship through a riser, and the gas production pipeline is arranged in the riser; the bottom of the natural gas collection cover is surrounded by an anchor system, and the bottom of the natural gas collection cover is provided with a pressure Adjustment system, the outer wall of the natural gas collection hood is provided with a propulsion system, the side wall of the natural gas collection hood is provided with a density adjustment system, the inside of the natural gas collection hood is provided with a temperature adjustment system and an agitation system, and the temperature adjustment system It includes a heating device, a heating pipeline, a heat exchanger and a return water pipeline. The mother ship is provided with a heating device, and the heating device is connected with a heating pipeline, and the heating pipeline passes through the insulation The water pipe leads to the inside of the natural gas collection cover, and the natural gas collection cover is provided with a number of branch pipelines connected to the heating pipeline, and a number of heat exchangers are arranged on the branch pipelines; the branch pipelines are connected to the natural gas collection cover With the same frame structure, the branch pipeline is connected to the return water pipeline, and the water return pipeline is connected to the heating device on the mother ship through the riser.

Due to the above structure, the mother ship is used for the operation and control of the operator on the sea surface. The natural gas collection cover can be covered on the seabed mud bed in a designated area, and the seabed mud bed in the area is sealed, and the natural gas in the area is collected, and transmitted to the natural gas storage device on the mother ship through the natural gas production pipeline. Collection and storage. The water riser is used to place all gas production pipelines, air pressure pipelines, heating pipelines and cables in it to avoid seawater corrosion and ensure its life. The anchoring system is located around the bottom of the natural gas collection cover, which can seal and fix the collection cover on the seabed mud bed to ensure leakage during natural gas collection. The pressure regulating system can discharge the liquid in the collection cover, so that a negative pressure is formed in the closed collection cover, and the natural gas hydrate in the seabed mud bed is promoted to decompose, which is beneficial to the exploitation of the seabed natural gas hydrate. The agitation system is to stir the seabed mud bed through the agitation system after collecting in the designated area for a certain period of time, so as to promote the decomposition of deep hydrate in the seabed mud bed. The propulsion system can be used to make fine adjustments to the collection hood when lowering the natural gas collection hood to the designated area, so as to ensure the precise positioning of the collection hood. The density adjustment system is to adjust the density of the natural gas collection cover itself, so as to control the lifting and lowering of the collection cover. All the buoyancy modules are arranged between the inner and outer shells of the collection cover, so that the overall structure of the collection cover is more compact and simpler, and the collection cover is not easily affected by the external environment to move, which is more convenient for transportation and storage. The temperature regulation system is mainly used to adjust the temperature inside the collection hood. When the temperature inside the natural gas collection hood is too low, the heating device can be used to supply hot water to the natural gas collection hood through the heating pipeline to make the energy of the hot water It is transferred to the heating pipeline in the natural gas collection cover. When the hot water reaches the natural gas collection cover, it is divided into each branch pipeline and then enters the heat exchanger. The heat exchanger collects the heat of the hot water in the natural gas. The natural gas is released in the hood to increase the temperature in the natural gas collection hood and ensure the normal collection operation of natural gas. After heat exchange, the hot water returns to the heating device through the return water pipeline, thereby forming a circular flow that can be reused. Among them, the branch pipeline is a frame structure with the same shape as the natural gas collection cover, so that the heat energy distribution of the entire collection cover and its interior is uniform, so as to avoid the local temperature in the collection cover from being too high, forming a large temperature difference, and causing the instantaneous expansion pressure of natural gas to increase instantaneously. Large, dangerous accidents brought about to ensure production safety. The submarine natural gas collection device with built-in buoyancy tank circulating hot water pipeline heating of the present invention mainly solves the problem that the natural gas hydrate in the seabed mud bed will not form the escape and leakage of natural gas during the process of decomposing, collecting and exploiting. The invention breaks through the conventional thinking mode, and cleverly uses pressure regulation to form negative pressure and temperature regulation system to increase the temperature, so as to promote the decomposition of natural gas hydrate in the seabed mud bed, which is beneficial to the exploitation of seabed natural gas hydrate, and then greatly improves the natural gas collection rate. It provides a new direction for the exploitation of seabed natural gas hydrate; it can be seen that the present invention can ensure stable production through the control of density, pressure and temperature, and the natural gas collection is convenient and efficient, and can be reused many times.

In the submarine natural gas collection device heated by circulating hot water pipes with built-in buoyancy tanks of the present invention, the density adjustment system includes a buoyancy module, a pressure supply module and an air pressure pipeline; the inner and outer shells arranged on the natural gas collection cover are arranged There are a number of buoyancy modules, the buoyancy module includes a sealed inner hollow box, the box is equipped with an electronic liquid level gauge, and the box is provided with a drain pipe and an air intake pipe connecting the inside and outside, and the air intake pipes of all buoyancy modules It is connected in parallel with the air pressure pipeline, and the air pressure pipeline is fixed on the shell of the natural gas collection cover and passed through the water riser to connect to the pressure supply module, and the pressure supply module is arranged on the mother ship.

Due to the above structure, the density adjustment system generates pressure gas through the pressure supply module, and supplies pressure gas into the tank of the buoyancy module through the air pressure pipeline, so that the water in the tank can be discharged, thereby reducing the density of the collection cover itself for lifting; On the contrary, when the collection cover is lowered, the pressure gas in the control box can be discharged, and the seawater enters the box to increase the density of the collection cover itself, so that the collection cover is lowered to the seabed mud bed. All the buoyancy modules are arranged between the inner and outer shells of the collection cover, so that the overall structure of the collection cover is more compact and simpler, and the collection cover is not easily affected by the external environment to move, which is more convenient for transportation and storage.

In the subsea natural gas collection device heated by a circulating hot water pipeline with a built-in buoyancy tank according to the present invention, the natural gas collection cover includes a shell, a top platform, a baffle plate and a suspension ring, the shell includes an inner and outer shell, and the shell is an inner shell. An empty pyramid-shaped structure, the top of the housing is set as a top platform, a ring-shaped baffle is sealed and connected to the bottom of the housing, and a number of suspension rings are provided in the middle of the outer wall of the housing. The branch pipeline Inside the housing is a pyramid frame structure.

Due to the above structure, the hollow pyramid-shaped shell makes the shell easy to manufacture, and the structure is more reliable, which is more conducive to the concentration of natural gas on the inner top of the shell and the collection of weather. The buoyancy module can be set between the inner and outer shells, so that the structure of the whole collection cover is more compact; the top platform is used to connect the riser, which is convenient for the connection between the mother ship and the collection cover. The annular baffle at the bottom of the casing can seal the bottom of the collection cover with the seabed mud bed, thereby ensuring the formation of negative pressure in the collection cover, promoting the decomposition of natural gas hydrate in the seabed mud bed, and facilitating the exploitation of seabed natural gas hydrate . On the one hand, the lifting ring can be used to lift the collection cover, and on the other hand, it can be used to connect the floating buoyancy module to improve the control ability of the buoyancy of the collection cover. Wherein the branch pipeline has a pyramid frame structure in the casing, so that it can match the inner cavity structure of the natural gas collection cover, and when the natural gas collection cover is heated, the heat energy in the entire collection cover and its interior can be evenly distributed , so as to avoid the local temperature in the collection hood being too high, forming a large temperature difference, causing the instantaneous expansion pressure of the natural gas to increase instantly, and causing dangerous accidents, ensuring production safety.

In the submarine natural gas collection device heated by circulating hot water pipes with built-in buoyancy tanks of the present invention, the anchoring system is arranged around the bottom of the natural gas collection cover, and the anchoring system includes a screw, a motor, a transmission device and a closed anchoring shell. The anchoring shell is fixed on the upper part of the baffle, and a motor is fixed in the anchoring shell, and the electric motor is connected to the transmission device and drives the screw to rotate, and the screw passes through the bottom of the anchoring shell.

Due to the above structure, the motor can be used to control the screw rod through the transmission device, and the screw rod can be extended into the seabed mud bed, and the collection cover is fixed on the seabed mud bed, so as to ensure the sealing and stability of the collection cover, and avoid the influence of seabed environmental factors on the collection cover. Therefore, the problem of escape and leakage of natural gas can be effectively avoided during the process of decomposition, collection and exploitation.

In the subsea natural gas collection device heated by a circulating hot water pipeline with a built-in floating tank of the present invention, one end of the gas production pipeline is located on the top platform and communicates with the inside of the natural gas collection cover, and the other end is located on the mother ship to connect to the natural gas collection and storage device; There are gas extraction pipelines, air pressure pipelines, heating pipelines and cables.

Due to the above structure, the gas production pipeline is mainly used to connect the natural gas collection cover and the natural gas storage device, and the natural gas collected in the collection cover can be transmitted to the natural gas storage device through the gas production pipeline. Among them, the riser can be used for the pipelines and cables connected between the mother ship and the collection cover, effectively protecting the pipelines and cables and making them last longer.

In the submarine natural gas collection device heated by the circulating hot water pipeline of the built-in buoyancy tank of the present invention, the pressure regulation system is arranged at the bottom of the natural gas collection cover. Inside the cover, the submersible pump is fixed on the natural gas collection cover, the submersible pump is connected to the suction box through the water inlet hose, and the submersible pump is connected to the outside of the natural gas collection cover through the water outlet pipe.

Due to the above structure, the pressure regulating system can discharge the seawater inside the collection cover to the outside of the collection cover through the water suction box through the water inlet hose and the submersible pump, so that a negative pressure is formed inside the collection cover, which is more conducive to promoting the growth of the seabed mud bed species. The decomposition of natural gas hydrate is beneficial to the exploitation of subsea natural gas hydrate, and then greatly improves the natural gas collection rate; at the same time, the pressure regulation system can also ensure the stability of the internal pressure of the natural gas collection cover.

In the subsea natural gas collection device heated by a circulating hot water pipeline with a built-in floating tank of the present invention, a stirring system is provided on the inner lower side of the natural gas collecting cover, and the stirring system includes a crane and a water jet device, and the crane is fixed on the inner wall of the housing , the water jet device is installed on the vehicle and can move with the vehicle.

Due to the above structure, when the natural gas hydrate in the same designated seabed area is collected for a certain period of time, the agitation system will be activated to control the water jet device to aim at the seabed mud bed and spray high-pressure water to stir the seabed mud bed to promote the decomposition of deep hydrates, which is beneficial to the seabed The exploitation of natural gas hydrates can greatly increase the recovery rate of natural gas.

In the submarine natural gas collection device heated by a circulating hot water pipeline with a built-in buoyancy tank of the present invention, the propulsion system includes a carrying platform, a propeller propeller and a motor, the carrying platform is fixed in the middle of the outer side of the natural gas collection cover, and the motor is connected to the propeller propeller for installation. on the platform.

Due to the above structure, when the collection cover is lowered close to the predetermined position, the propulsion system can be activated to fine-tune the position of the natural gas collection cover, which can ensure that the collection cover reaches the predetermined position, which is more conducive to the collection of natural gas in the predetermined area.

In the submarine natural gas collection device heated by a circulating hot water pipeline with a built-in buoyancy tank of the present invention, a monitoring system is provided in the natural gas collection cover, and the monitoring system includes a temperature and pressure monitoring device and a shell stress monitoring device. The pressure monitoring device is installed inside the top platform, and several shell stress monitoring devices are installed outside the shell of the natural gas collection cover; the monitoring system, propulsion system, pressure regulation system, anchoring system, stirring system and density regulation Connect to the control center.

Due to the above structure, the monitoring system can effectively monitor the pressure and temperature values in and on the collection hood, so that the collection hood can be monitored in real time, avoiding the danger of excessive pressure on the natural gas collection hood, and ensuring safe and reliable operation ; Or the temperature is too low to collect natural gas, so as to improve the natural gas collection rate.

The seabed natural gas hydrate collection method heated by the circulating hot water pipeline of the built-in buoyancy tank of the present invention is realized by the following steps:

Step 1. The mother ship transports a number of natural gas collection covers to the designated seabed area, controls the density adjustment system to fill the buoyancy module with water, controls the natural gas collection cover to be lowered to a predetermined position, and starts the propulsion system to fine-tune the position of the natural gas collection cover;

Step 2. After the natural gas collection cover reaches the predetermined position, control the annular baffle to insert into the seabed mud bed, start the anchoring system to make the screw extend into the seabed mud bed, and fix and seal the natural gas collection cover;

Step 3. Turn on the pressure regulating system to discharge the seawater inside the natural gas collection hood, so that negative pressure is formed inside the natural gas collection hood to promote the decomposition of hydrates. The natural gas hydrates are collected through the gas production pipeline and processed and stored in the natural gas collection and storage device. At the same time, the monitoring system Monitor the pressure change inside the natural gas collection hood, adjust the working status of the pressure regulation system in real time, and ensure the stability of the internal pressure of the natural gas collection hood;

Step 4. The monitoring system monitors the internal temperature value of the natural gas collection hood, and compares the detected temperature value with the set value. If the temperature value is low, the temperature adjustment system is activated, and the heating device supplies hot water to the heating pipeline , the hot water enters the inside of the natural gas collection hood along the heating pipeline and is diverted to each branch pipeline, so that the heat energy of the hot water can be exchanged in the heat exchangers on each branch pipeline to increase the internal temperature of the natural gas collection hood, and then through the return The water pipeline returns to the heating device; when the temperature reaches the preset value, the heating device is controlled to stop supplying hot water;

Step 5. After collecting natural gas hydrates in the same designated seabed area for a certain period of time, start the agitation system, control the water jet device to align with the seabed mud bed and spray high-pressure water flow, and stir the seabed mud bed to promote the decomposition of deep hydrates;

Step 6. When the natural gas exploitation in the specified seabed area is completed, the density adjustment system will supply gas to the buoyancy module to reduce the overall density of the natural gas collection cover, the anchoring system will be released, and the natural gas collection cover will float up and out of contact with the seabed mud bed. The propulsion system pushes the natural gas collection hood to move to the next area to be exploited, repeating steps 2 to 5.

Due to the above method, the precise control of the natural gas collection cover is applied to the collection of subsea natural gas, providing a new direction for the exploitation of subsea natural gas hydrate. The collection method of the present invention solves the problem that the natural gas hydrate in the seabed mud bed will not be dissipated and leaked during the process of decomposing, collecting and exploiting. The negative pressure and temperature adjustment system increase the temperature to promote the decomposition of natural gas hydrate in the seabed mud bed, which is beneficial to the exploitation of seabed natural gas hydrate, and then greatly improves the natural gas collection rate. It can be used repeatedly and has a long service life.

In summary, owing to adopting above-mentioned technical scheme, the beneficial effect of the present invention is:

1. The submarine natural gas collection device and method heated by the built-in buoyancy tank circulating hot water pipeline of the present invention mainly solves the problem of natural gas hydrate in the seabed mud bed, and does not cause the escape and leakage of natural gas during the process of decomposing, collecting and exploiting The present invention breaks through the conventional thinking mode, cleverly utilizes pressure regulation to form negative pressure and temperature regulation system to increase temperature, so as to promote the decomposition of natural gas hydrate in the seabed mud bed, which is beneficial to the exploitation of seabed natural gas hydrate, and then greatly improves the natural gas production rate. The recovery rate provides a new direction for the exploitation of seabed gas hydrate.

2. The present invention can ensure stable production through the control of density, pressure and temperature. The natural gas collection is convenient, the collection efficiency is high, and it can be reused many times. The concept is novel, the structure is ingenious, and the service life is long. It can be widely used in seabed natural gas collection , has a wide range of applications and is suitable for popularization and application.

Description of drawings

The invention will be illustrated by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a structural schematic diagram of the temperature regulating system in the present invention.

Fig. 3 is a schematic diagram of the buoyancy module in the present invention.

Marks in the figure: 101-shell, 102-top platform, 103-baffle plate, 104-lift ring; 201-buoyancy module, 202-pressure supply module, 203, 11-air pressure pipeline, 204-electric valve, 205-inlet Air pipe, 206-drainage pipe, 207 electronic liquid level gauge; 3-pressure regulation system, 301-submersible pump, 302-suction tank;, 401-heating pipeline, 402-heating device, 403-heat exchanger, 404 -Return water pipeline; 5-mother ship, 6-propulsion system, 7-natural gas collection and storage device, 801-screw, 802-electric motor, 803-transmission device; 9-stirring system, 10-monitoring system, 12-gas production pipeline, 13 - Riser.

Detailed ways

All features disclosed in this specification, or steps in all methods or processes disclosed, may be combined in any manner, except for mutually exclusive features and/or steps.

Any feature disclosed in this specification (including any appended claims, abstract), unless otherwise stated, may be replaced by alternative features that are equivalent or serve a similar purpose. That is, unless expressly stated otherwise, each feature is one example only of a series of equivalent or similar features.

As shown in Figures 1 to 3, the submarine natural gas collection device heated by the circulating hot water pipeline of the built-in buoyancy tank of the present invention includes a mother ship 5 and an inner empty natural gas collection cover, and said mother ship 5 is provided with a natural gas collection and storage device 7, The natural gas collection and storage device 7 is connected to the top of the natural gas collection cover through the gas production pipeline 12, and the natural gas collection cover is connected to the bottom of the mother ship 5 through the riser 13, and the gas production pipeline 12 is arranged in the water riser 13; An anchoring system is arranged around the bottom of the hood, a pressure regulation system 3 is provided at the bottom of the natural gas collection hood, a propulsion system 6 is provided on the outer wall of the natural gas collection hood, and a density adjustment system is provided inside the side wall of the natural gas collection hood. The inside of the natural gas collection cover is provided with a temperature regulation system and an agitation system 9. The temperature regulation system includes a heating device 402, a heating pipeline 401, a heat exchanger 403 and a return water pipeline 404. The mother ship 5 is provided with A heat supply device 402, the heat supply device 402 is connected with a heat supply pipeline 401, and the heat supply pipeline 401 passes through the water riser 13 to the inside of the natural gas collection cover. A branch pipeline connected to the pipeline 401, on which a number of heat exchangers 403 are arranged; the branch pipeline is a frame structure with the same shape as the natural gas collection cover, and the branch pipeline is connected to the return water pipeline 404, The return water pipeline 404 is connected to the heating device 402 on the mother ship 5 through the riser 13 .

Wherein the density adjustment system includes a buoyancy module 201, a pressure supply module 202 and an air pressure pipeline 203; a number of buoyancy modules 201 are arranged between the inner and outer shells arranged on the natural gas collection cover, and the buoyancy modules 201 include sealing The inner empty box body, the electronic liquid level gauge 207 is set in the box body, the drainage pipe 206 and the air inlet pipe 205 connecting the inside and outside are arranged on the said box body, and the air inlet pipes 205 of all the buoyancy modules 201 are connected in parallel to the air pressure pipeline 203 Above, the air pressure pipeline 203 is fixed on the shell of the natural gas collection cover and passes through the riser 13 to connect to the pressure supply module 202 , and the pressure supply module 202 is arranged on the mother ship 5 .

Wherein the natural gas collection cover comprises a housing 101, a top platform 102, a baffle plate 103 and a suspension ring 104, the housing 101 comprises an inner and outer shell, the housing 101 is an inner hollow pyramid structure, the housing The top of 101 is set as the top platform 102, and the bottom edge of the housing 101 is sealed with a ring-shaped baffle 103, and the middle part of the outer wall of the housing 101 is provided with several lifting rings 104; The interior is a pyramid frame structure.

Wherein the anchoring system is arranged around the bottom of the natural gas collection cover, the anchoring system includes a screw 801, a motor 802, a transmission 803 and an airtight anchoring shell, the anchoring shell is fixed on the top of the baffle plate 103, and the anchoring shell A motor 802 is fixed inside, and the motor 802 is connected to a transmission device 803 and drives a screw rod 801 to rotate, and the screw rod 801 passes through the bottom of the anchor shell.

One end of the gas production pipeline 12 is located on the top platform 102 and connected to the inside of the natural gas collection cover, and the other end is located on the mother ship 5 and connected to the natural gas collection and storage device 7; the riser 13 is provided with a gas production pipeline 12 and a pneumatic pipeline 203 , heating pipeline 401 and cables.

Wherein said pressure regulating system 3 is arranged at the bottom of the natural gas collection cover, said pressure regulating system 3 comprises a submersible pump 301 and a water suction box 302, said water suction box 302 is placed inside the natural gas collection cover, and said submersible pump 301 is fixed on the natural gas On the collection cover, the submersible pump 301 is connected to the suction box 302 through a water inlet hose, and the submersible pump 301 is connected to the outside of the natural gas collection cover through a water outlet pipe.

Wherein the internal lower side of the natural gas collection cover is provided with a stirring system 9, the stirring system 9 includes a crane 901 and a water jet device 902, the crane 901 is fixed on the inner wall of the housing 101, and the water jet device 902 is installed on the crane The 901 can move with the vehicle.

Wherein the propulsion system 6 includes a carrying platform, a propeller propeller and a motor, the carrying platform is fixed in the middle of the outer side of the natural gas collection cover, and the motor is connected to the propeller propeller and installed on the carrying platform.

Wherein the natural gas collection cover is provided with a monitoring system 10, the monitoring system 10 includes a temperature and pressure monitoring device, and a shell stress monitoring device, the temperature and pressure monitoring device is installed inside the top platform 102, several shell stress The monitoring device is installed outside the casing 101 of the natural gas collection cover; the monitoring system 10, the propulsion system 6, the pressure regulation system 3, the anchoring system, the agitation system 9 and the density regulation system are respectively connected to the control center through cables.

The mother ship is used by the operator to operate and control on the sea surface. The natural gas collection cover can be covered on the seabed mud bed in a designated area, and the seabed mud bed in the area is sealed, and the natural gas in the area is collected, and transmitted to the natural gas storage device on the mother ship through the natural gas production pipeline. Collection and storage. The water riser is used to place all gas production pipelines, air pressure pipelines, heating pipelines and cables in it to avoid seawater corrosion and ensure its life. The anchoring system is located around the bottom of the natural gas collection cover, which can seal and fix the collection cover on the seabed mud bed to ensure leakage during natural gas collection. The pressure regulating system can discharge the liquid in the collection cover, so that a negative pressure is formed in the closed collection cover, and the natural gas hydrate in the seabed mud bed is promoted to decompose, which is beneficial to the exploitation of the seabed natural gas hydrate. The agitation system is to stir the seabed mud bed through the agitation system after collecting in the designated area for a certain period of time, so as to promote the decomposition of deep hydrate in the seabed mud bed. The propulsion system can be used to make fine adjustments to the collection hood when lowering the natural gas collection hood to the designated area, so as to ensure the precise positioning of the collection hood. The density adjustment system is to adjust the density of the natural gas collection cover itself, so as to control the lifting and lowering of the collection cover. All the buoyancy modules are arranged between the inner and outer shells of the collection cover, so that the overall structure of the collection cover is more compact and simpler, and the collection cover is not easily affected by the external environment to move, which is more convenient for transportation and storage. The temperature regulation system is mainly used to adjust the temperature inside the collection hood. When the temperature inside the natural gas collection hood is too low, the heating device can be used to supply hot water to the natural gas collection hood through the heating pipeline to make the energy of the hot water It is transferred to the heating pipeline in the natural gas collection cover. When the hot water reaches the natural gas collection cover, it is divided into each branch pipeline and then enters the heat exchanger. The heat exchanger collects the heat of the hot water in the natural gas. The natural gas is released in the hood to increase the temperature in the natural gas collection hood and ensure the normal collection operation of natural gas. After heat exchange, the hot water returns to the heating device through the return water pipeline, thereby forming a circular flow that can be reused. Among them, the branch pipeline is a frame structure with the same shape as the natural gas collection cover, so that the heat energy distribution of the entire collection cover and its interior is uniform, so as to avoid the local temperature in the collection cover from being too high, forming a large temperature difference, and causing the instantaneous expansion pressure of natural gas to increase instantaneously. Large, dangerous accidents brought about to ensure production safety. The submarine natural gas collection device with built-in buoyancy tank circulating hot water pipeline heating of the present invention mainly solves the problem that the natural gas hydrate in the seabed mud bed will not form the escape and leakage of natural gas during the process of decomposing, collecting and exploiting. The invention breaks through the conventional thinking mode, and cleverly uses pressure regulation to form negative pressure and temperature regulation system to increase the temperature, so as to promote the decomposition of natural gas hydrate in the seabed mud bed, which is beneficial to the exploitation of seabed natural gas hydrate, and then greatly improves the natural gas collection rate. It provides a new direction for the exploitation of seabed natural gas hydrate; it can be seen that the present invention can ensure stable production through the control of density, pressure and temperature, and the natural gas collection is convenient and efficient, and can be reused many times.

The seabed natural gas hydrate collection method heated by the circulating hot water pipeline of the built-in buoyancy tank of the present invention is realized by the following steps:

Step 1. The mother ship 5 transports a number of natural gas collection covers to the designated seabed area, controls the density adjustment system to fill the buoyancy module 201 with water, controls the natural gas collection covers to be lowered to a predetermined position, and starts the propulsion system 6 to fine-tune the position of the natural gas collection covers;

Step 2: After the natural gas collection cover reaches the predetermined position, control the annular baffle 103 to insert into the seabed mud bed, start the anchoring system to make the screw 801 extend into the seabed mud bed, and fix and seal the natural gas collection cover;

Step 3: Open the pressure regulating system 3 to discharge the seawater inside the natural gas collection hood, so that a negative pressure is formed inside the natural gas collection hood to promote the decomposition of hydrates, and the natural gas hydrates are collected through the gas production pipeline 12 to the natural gas collection and storage device 7 for processing and storage. Simultaneously, the monitoring system 10 monitors the internal pressure change of the natural gas collection cover, and adjusts the working state of the pressure regulation system 3 in real time to ensure the stability of the internal pressure of the natural gas collection cover;

Step 4: The monitoring system 10 monitors the internal temperature value of the natural gas collection cover, and compares the detected temperature value with the set value. If the temperature value is low, the temperature regulation system is activated, and the heating device 402 supplies heat to the heating pipeline 401. into the hot water, the hot water enters the inside of the natural gas collection cover along the heating pipeline 401 and is distributed to each branch pipeline, so that the heat energy of the hot water is exchanged in the heat exchanger 403 on each branch pipeline, and the internal gas collection cover of the natural gas collection cover is improved. temperature, and then return to the heating device 402 through the return pipe 404; when the temperature reaches a preset value, the heating device 402 is controlled to stop supplying hot water;

Step 5. After collecting natural gas hydrates in the same designated seabed area for a certain period of time, start the agitation system 9, control the water jet device 902 to aim at the seabed mud bed and spray high-pressure water flow, and stir the seabed mud bed to promote the separation of deep hydrates;

Step 6: After the natural gas exploitation in the designated seabed area is completed, the density adjustment system supplies gas to the buoyancy module 201 to reduce the overall density of the natural gas collection cover, the anchoring system is released, and the natural gas collection cover is lifted and floated away from the seabed mud bed. Contact, the propulsion system 6 pushes the natural gas collection cover to move to the next area to be exploited, and repeats steps 2 to 5.

Through the control of precise natural gas collection cover, it is applied to the collection of subsea natural gas, providing a new direction for the exploitation of subsea natural gas hydrate. The collection method of the present invention solves the problem that the natural gas hydrate in the seabed mud bed will not be dissipated and leaked during the process of decomposing, collecting and exploiting. The negative pressure and temperature adjustment system increase the temperature to promote the decomposition of natural gas hydrate in the seabed mud bed, which is beneficial to the exploitation of seabed natural gas hydrate, and then greatly improves the natural gas collection rate. It can be used repeatedly and has a long service life.

The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, and any new method or process step or any new combination disclosed.

Claims (9)

1. The sea-bottom natural gas collection device that buoyancy tank circulating hot water pipeline built in 1. heats, it is characterised in that: including lash ship (5) and interior Empty natural gas collecting hood, the lash ship (5) are equipped with natural gas storage device (7), and the natural gas storage device (7) passes through Gas production pipe (12) connects at the top of natural gas collecting hood, and the natural gas collecting hood is connected to lash ship (5) by marine riser (13) Bottom, the gas production pipe (12) are set in marine riser (13)；Natural gas collecting hood bottom surrounding is disposed with anchoring system, Pressure regulating system (3) are equipped in the bottom of natural gas collecting hood, the natural gas collects cover outer wall and is equipped with propulsion system (6), it is equipped with Auto-regulating System of Density of Heavy Medium system in the side wall of the natural gas collecting hood, is equipped with temperature inside the natural gas collecting hood and adjusts System (4) and agitation system (9), the humidity control system include heating plant (402), heat supplying pipeline (401), heat exchanger (403) and water return pipeline (404), the lash ship (5) are equipped with heating plant (402), are connected on the heating plant (402) Heat supplying pipeline (401), the heat supplying pipeline (401) pass through inside marine riser (13) to natural gas collecting hood, and the natural gas is received Several branch lines being connected with heat supplying pipeline (401) are equipped in collection cover, the branch line is equipped with several heat exchangers (403)；The branch line is frame structure identical with natural gas collection hood shape, and the branch line connects water return pipeline (404), the water return pipeline (404) passes through marine riser (13) and is connected to heating plant (402) on lash ship (5)；The density tune Section system includes buoyant module (201), for die block (202) and pneumatic circuit (203)；It is arranged on the natural gas collecting hood It is disposed between inside and outside layer shell several buoyant modules (201), the buoyant module (201) includes the interior empty van body of sealing, described It is set in cabinet electronic liquid level gauge (207), the cabinet is equipped with the inside and outside drainpipe (206) of connection and air inlet pipe (205), owns The air inlet pipe (205) of buoyant module (201) is parallel on pneumatic circuit (203), and the pneumatic circuit (203) is fixed on natural gas It passes through and is connected to for die block (202) on the shell of collecting hood and from marine riser (13), it is described to be set to mother for die block (202) On ship (5).
2. 2. the sea-bottom natural gas collection device of built-in buoyancy tank circulating hot water pipeline heating as described in claim 1, feature exist In: the natural gas collecting hood includes shell (101), top platform (102), baffle (103) and hanging ring (104), the shell It (101) include ectonexine shell, the shell (101) hollow pyramid structure is set as at the top of the shell (101) Top platform (102) is sealedly connected with a circle ring baffle (103), the shell (101) on the bottom edge of the shell (101) Outer wall in the middle part of be equipped with several hanging rings (104)；The branch line is in pyramid frame structure in shell (101).
3. 3. the sea-bottom natural gas collection device of built-in buoyancy tank circulating hot water pipeline heating as claimed in claim 2, feature exist In: the anchoring system is set to natural gas collecting hood bottom surrounding, and the anchoring system includes screw rod (801), motor (802), transmission device (803) and closed anchoring shell, the anchoring shell are fixed on baffle (103) top, in the anchoring shell It is fixed with motor (802), the motor (802) connects transmission device (803) and drives screw rod (801) rotary motion, institute State the bottom that screw rod (801) is pierced by anchoring shell.
4. 4. the sea-bottom natural gas collection device of built-in buoyancy tank circulating hot water pipeline heating as claimed in claim 2, feature exist In: one end of the gas production pipe (12) is located at top platform (102) and is connected to inside natural gas collecting hood, and the other end is located at mother Natural gas storage device (7) are connected on ship (5)；Wherein gas production pipe (12), pneumatic circuit are equipped in marine riser (13) (203), heat supplying pipeline (401) and cable.
5. 5. the sea-bottom natural gas collection device of built-in buoyancy tank circulating hot water pipeline heating as claimed in claim 2 or 3 or 4, Be characterized in that: the pressure regulating system (3) is set to the bottom of natural gas collecting hood, and the pressure regulating system (3) includes latent Water pump (301) and suction box (302), the suction box (302) are placed in inside natural gas collecting hood, and the immersible pump (301) is solid Due on natural gas collecting hood, the immersible pump (301) is connected to suction box (302) by water supply hose, the immersible pump (301) It is connected to outside natural gas collecting hood by outlet pipe.
6. 6. the sea-bottom natural gas collection device of built-in buoyancy tank circulating hot water pipeline heating as claimed in claim 5, feature exist In: the inner lower of the natural gas collecting hood is equipped with agitation system (9), and the agitation system (9) includes driving (901) and water Fluidic device (902), the driving (901) are fixed on shell (101) inner wall, and the water jet device (902) is installed on driving It (901) can following vehicle movement on.
7. 7. the sea-bottom natural gas collection device of built-in buoyancy tank circulating hot water pipeline heating as claimed in claim 5, feature exist In: the propulsion system (6) includes carrying platform, screw propeller and motor, and the carrying platform is fixed on natural gas The outer middle side part of collecting hood, motor connection screw propeller are mounted on carrying platform.
8. 8. the sea-bottom natural gas collection device of built-in buoyancy tank circulating hot water pipeline heating as claimed in claim 7, feature exist In being equipped with monitoring system (10) in: the natural gas collecting hood, the monitoring system (10) include temperature and pressure monitoring device, And shell stress monitoring device, the temperature and pressure monitoring device are mounted on top platform (102) inside, several shell stress The shell (101) that monitoring device is mounted on natural gas collecting hood is external；The monitoring system (10), propulsion system (6), pressure tune Section system (3), anchoring system, agitation system (9) and Auto-regulating System of Density of Heavy Medium system pass through cable connection in control centre respectively.
9. 9. a kind of sea of the sea-bottom natural gas collection device using built-in buoyancy tank circulating hot water pipeline heating according to any one of claims 8 Bottom gas hydrates acquisition method, it is characterised in that: it is realized by following steps:

   Step 1, lash ship (5) are if transport dry gas collecting hood controls Auto-regulating System of Density of Heavy Medium system to buoyancy mould to specified sea-bed area Block (201) interior water-filling, when control natural gas collecting hood is transferred to close to predetermined position, natural gas is received in starting propulsion system (6) Collection cover carries out fine position；

   After step 2, natural gas collecting hood reach predetermined position, seabed mud bed, starting anchoring system are inserted into control ring baffle (103) System protrudes into screw rod (801) in the mud bed of seabed, and natural gas collecting hood is fixed and sealed；

   The seawater inside natural gas collecting hood is discharged in step 3, cracking pressure regulating system (3), makes shape inside natural gas collecting hood Promote decomposition of hydrate at negative pressure, gas hydrates are collected by gas production pipe (12) to place in natural gas storage device (7) Reason and storage, while system (10) monitoring natural gas collecting hood internal pressure variation is monitored, adjust pressure regulating system (3) in real time Working condition, it is ensured that the internal pressure of natural gas collecting hood is stablized；

   Step 4, monitoring system (10) monitor natural gas collecting hood internal temperature values, and will test temperature value and compared with setting value Compared with if temperature value is lower, start-up temperature regulating system, heating plant (402) feeds hot water, heat into heat supplying pipeline (401) Water enters inside natural gas collecting hood along heat supplying pipeline (401) and branches to each branch line, makes the thermal energy of hot water in each branch Heat exchanger (403) on pipeline carries out heat exchange, improves the internal temperature of natural gas collecting hood, then through water return pipeline (404) It is back to heating plant (402)；When temperature value reaches preset value, control heating plant (402) stops hot-water supply；

   Step 5, when in same specified sea-bed area gas hydrates acquisition after a certain period of time, start agitation system (9), control Water jet device (902) processed is directed at seabed mud bed and sprays high pressure water flow, and agitation seabed mud bed promotes deep layer decomposition of hydrate；

   Step 6, after the completion of the natural gas extraction of specified sea-bed area, Auto-regulating System of Density of Heavy Medium system to buoyant module (201) by supplying Gas reduces the global density of natural gas collecting hood, and anchoring system, which releases, fixes, and natural gas collecting hood floats and is detached from and seabed mud The contact of bed, propulsion system (6) push natural gas collecting hood to be moved to next domain to be exploited, repeat step 2 to step 5.