CN112360400B

CN112360400B - Offshore combustible ice mining, digging and backfilling device and method

Info

Publication number: CN112360400B
Application number: CN202011172726.5A
Authority: CN
Inventors: 高盟; 张粮; 王滢
Original assignee: Shandong University of Science and Technology
Current assignee: Shandong University of Science and Technology
Priority date: 2020-10-28
Filing date: 2020-10-28
Publication date: 2022-04-12
Anticipated expiration: 2040-10-28
Also published as: CN112360400A

Abstract

The invention discloses a device and a method for excavating and backfilling offshore combustible ice, which relate to the field of combustible ice exploitation and comprise an exploitation platform, a telescopic pipe, a drilling mechanism, a backfilling mechanism and a collecting and storing mechanism, wherein one end of the telescopic pipe is arranged on the exploitation platform and is communicated with the collecting and storing mechanism, the other end of the telescopic pipe is butted and communicated with a duct piece, the drilling mechanism is arranged in the telescopic pipe, the output end of the backfilling and grouting mechanism is positioned in the telescopic pipe and faces the duct piece, the telescopic pipe can drive the duct piece to move along the axial direction, the communication relation between a combustible ice storage layer and the exploitation platform is established by matching the telescopic pipe piece with the duct piece, the telescopic pipe and the pipe piece are used as an air inlet pipeline to guide the gas released by the reservoir to a collecting and storing mechanism for storage, thereby completing the safe mining process, the disposable segment can be used for well plugging a mining area after being injected with backfill materials, so that the residual in the storage layer is prevented from overflowing, and the effects of safe backfill and plugging are achieved.

Description

Offshore combustible ice mining, digging and backfilling device and method

Technical Field

The disclosure relates to the field of combustible ice mining, in particular to a device and a method for mining, excavating and backfilling marine combustible ice.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The combustible ice is a mixture mainly composed of methane (CH)₄) Gas and water molecule (H)₂O) ice-like crystalline material formed under low temperature and high pressure conditions. Researches find that 1 cubic meter of combustible ice can be decomposed into 164 cubic meters of natural gas, only carbon dioxide and water can be generated after combustion, solid residues can not be left, harmful gas can not be generated, and the energy source is a novel clean energy source with high combustion value and no pollution.

The inventors have found that the principle of the existing production method mainly involves changing the temperature and pressure conditions of the combustible ice reservoir, inducing its decomposition, and thereby releasing methane. 1) A thermal excitation mining method: the method is used for directly heating a combustible ice reservoir to enable the temperature of the reservoir to exceed the equilibrium temperature of the reservoir, so that the combustible ice is decomposed into methane and water. However, the method has not solved the problem of low heat utilization rate, and the combustible ice reservoirs on the seabed are not concentrated into one piece, are not a large rock, and are distributed uniformly. 2) And (3) a reduced pressure mining method: when free gas or other fluid is present below the combustible ice reservoir, the pressure of the combustible ice reservoir is reduced by pumping out the free gas or other fluid below. The method is low in cost and suitable for large-area mining, but is only economically feasible when the combustible ice deposit is positioned near the temperature and pressure balance boundary. 3) Chemical reagent injection mining method: injecting chemical agent into the combustible ice storage layer, such as salt water, methanol, ethanol, etc., to break the phase equilibrium state of the combustible ice storage layer and promote the decomposition of the combustible ice. However, chemical agents are expensive, slow acting and can also cause environmental pollution problems. 4) Substitution method: under certain temperature conditions, the pressure ratio CO required for the combustible ice to be stable₂The hydrates are higher. Thus, CO is injected into the combustible ice reservoir within a specific pressure range₂Gas, CO₂The gas may react with the combustible ice to form methane and CO₂A hydrate. However, this method may result in a large amount of CO₂The leakage of gas causes serious greenhouse effect. 5) A solid mining method: the combustible ice is promoted to be decomposed into a gas-liquid mixture in the reservoir, mixed slurry mixed with gas, liquid and solid hydrate is collected, and then the slurry is guided into a production platform for processing. However, some areas of combustible ice are mainly present in seabed sediments, and the methods have various degrees of high efficiency, economy and environmental ecology problems when the method faces the exploitation of marine combustible ice; most of the technologies still stay in the test stage, and only combustible ice can be exploited, and special equipment is still required to be additionally configured for exploring a combustible ice reservoir, so that the continuous working process of exploitation after exploration is difficult to realize.

Disclosure of Invention

The purpose of the disclosure is to provide a device and a method for excavating and backfilling offshore combustible ice, aiming at the defects in the prior art, a communication relation between a combustible ice reservoir and an exploitation platform is established by matching a telescopic pipe with a duct piece, the telescopic pipe and the duct piece are used as an air inlet pipeline to guide gas released by the reservoir to a collecting and storing mechanism for storage, a safe exploitation process is completed, the jettisonable duct piece can well plug an exploitation area after being injected with backfill materials, the residual in the reservoir is prevented from overflowing, and the effects of safe backfilling and plugging are achieved.

The first purpose of the disclosure is to provide a marine combustible ice mining, digging and backfilling device, which adopts the following technical scheme:

the device comprises a mining platform, a telescopic pipe, a drilling mechanism, a backfilling mechanism and a collecting and storing mechanism, wherein one end of the telescopic pipe is installed on the mining platform and is communicated with the collecting and storing mechanism, the other end of the telescopic pipe is in butt joint with a communicated pipe piece, the drilling mechanism is installed in the telescopic pipe, the output end of the backfilling and grouting mechanism is located in the telescopic pipe and faces the pipe piece, the telescopic pipe can drive the pipe piece to move axially, and gas released from a reservoir layer is conveyed to the collecting and storing mechanism to be stored as an air inlet pipeline of the collecting and storing mechanism.

Furthermore, the segment is coaxially and detachably butted with the end part of the telescopic pipe, and a ring cutter head is arranged at one end, away from the telescopic pipe, of the segment.

Furthermore, the backfill mechanism is installed on the mining platform and is communicated with the interior of the telescopic pipe through a backfill pipeline to form an output end of the backfill mechanism, and backfill materials are input to be matched with the segments to block the reservoir gas release opening.

Furthermore, the drilling mechanism comprises a drilling motor and a drill bit, wherein the drilling motor is connected with the drill bit through a linear moving pair and can drive the drill bit to move along the axis direction while rotating so as to change the distance between the drill bit and the seabed.

Furthermore, a drainage mechanism is installed on the inner wall of the telescopic pipe, the input end of the drainage mechanism is communicated with the inside of the telescopic pipe, the output end of the drainage mechanism penetrates through the wall of the telescopic pipe and extends out of the telescopic pipe, and a detection mechanism is arranged in the telescopic pipe.

Furthermore, the collecting and storing mechanism comprises a collector and a pressure chamber, the input end of the collector is communicated with one end of the telescopic pipe through a pipeline, a vacuum pump is arranged on the pipeline between the collector and the telescopic pipe, and the output end of the collector is communicated with the pressure chamber through a pipeline.

Furthermore, the filter is installed to the one end that flexible pipe connects the vacuum pump, and drilling mechanism installs between filter and section of jurisdiction.

The second purpose of the present disclosure is to provide a method for mining, excavating and backfilling combustible ice on the sea, which utilizes the above-mentioned device for mining, excavating and backfilling combustible ice on the sea, and comprises the following steps:

detecting the seabed, acquiring a combustible ice storage area, and moving the mining platform to the position above the storage area;

the telescopic pipe drives the duct piece to be lowered, so that the end part of the duct piece is inserted into the surface layer of the seabed, and water in the telescopic pipe is drained;

drilling the seabed below the drilling mechanism until the reservoir stratum is reached to destroy the phase equilibrium state in the reservoir stratum, and withdrawing the drilling mechanism;

the pipe piece is combined with the telescopic pipe to serve as an air inlet pipeline of the collecting and storing mechanism, and gas decomposed by the combustible ice in the reservoir is guided into the collecting and storing mechanism to be stored;

after the mining is finished, the collecting and storing mechanism is closed, the backfilling device inputs backfilling materials into the segment to plug the seabed drilled hole, and after the backfilling is finished, the segment is dismounted from the tail end of the telescopic pipe and the telescopic pipe is retracted.

Furthermore, when the driving pipe piece is placed downwards, the water body which is drawn out of the telescopic pipe is discharged outwards, so that pressure difference is formed between the inner part and the outer part of the water body, and the telescopic pipe and the pipe piece gradually sink to the seabed in combination with the self-weight action.

Further, when gas decomposed by the combustible ice is collected, the collecting and storing mechanism operates and maintains negative pressure in the telescopic pipe to guide the combustible ice storage layer to release the gas.

Compared with the prior art, the utility model has the advantages and positive effects that:

(1) the expansion pipe is matched with the pipe piece to establish a communication relation between the combustible ice reservoir and the mining platform, the expansion pipe and the pipe piece are used as gas inlet pipelines to guide gas released by the reservoir to the collecting and storing mechanism and then store the gas, so that a safe mining process is completed, compared with a traditional mining method, the method can be carried out more conveniently and safely, and the treatment process of the gas after mining is reduced;

(2) the mining area can be well plugged after the disposable duct piece is filled with the backfill material, the backfill material is combined with the duct piece to form a buckling structure, and a stable plugging structure can be formed after the other end of the duct piece is inserted into a seabed, so that compared with the traditional direct backfill grouting, the sealing structure increases the attachment area of the backfill material, thereby avoiding the residual overflow in the storage layer and achieving the effects of safe backfill and plugging;

(3) the adopted equipment has stronger leakproofness, can effectively avoid gas leakage, has no destructive influence on marine ecological environment, reduces cost and has exploration and backfill functions.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure.

Fig. 1 is a schematic overall structure diagram of a mining and backfilling device in

embodiments

1 and 2 of the present disclosure;

fig. 2 is a schematic structural view of a telescopic rod in

embodiments

1 and 2 of the present disclosure;

fig. 3 is a schematic view of the connection between the telescopic rod and the drilling mechanism in

embodiments

1 and 2 of the present disclosure;

fig. 4 is a schematic structural diagram of a collection and storage mechanism in

embodiments

1 and 2 of the present disclosure.

In the figure, 1 — the mining platform; 2-sea water layer; 3-seabed surface layer; 4-reservoir bed; 5-ring cutting head; 6-a duct piece; 7-solid drill bit; 8-a water inlet; 9-a water outlet; 10-draining pump; 11-a drill pipe; 12-a robotic arm; 13-backfilling the pipeline; 14-a pumping machine; 15-a drilling motor; 16-a track; 17-electromagnetic wave CT explorer; 18-segment motor; 19-backfill material; 20-a backfill valve; 21-vacuum pump means; 22-a vent hole; 23-a collector; 24-a collector valve; 25-constant temperature pressure chamber; 26-a refrigerator; 27-a valve; 28-trachea; 29-a controller; 30-a filter plate; 31-high molecular waterproof material; 32-a roller; 33-a collector conduit; 34-a vent valve; 35-vent valve; 36-internal piping.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an", and/or "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof;

for convenience of description, the words "up", "down", "left" and "right" in this disclosure, if any, merely indicate that the directions of movement are consistent with those of the figures themselves, and are not limiting in structure, but merely facilitate the description of the invention and simplify the description, rather than indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present disclosure.

As described in the background art, combustible ice exists mainly in seabed sediments in the prior art, and the methods have various problems of high efficiency, economy and environmental ecology when mining the marine combustible ice; most of the technologies stay in the test stage, only combustible ice can be exploited, and special equipment is required to be additionally configured for exploration of a combustible ice reservoir; in order to solve the problems, the disclosure provides a device and a method for excavating, backfilling and backfilling combustible ice on the sea.

Example 1

In an exemplary embodiment of the present disclosure, as shown in fig. 1-4, a marine combustible ice mining backfill apparatus is provided.

The system mainly comprises an exploitation platform, a telescopic pipe, a detection mechanism, a drilling mechanism, a backfill mechanism and a collection and storage mechanism;

the mining platform is used as a bearing mechanism for bearing other parts and driving the whole body to float on the sea surface, and the telescopic pipe is arranged on the mining platform and can be stretched and retracted back and forth along the vertical direction to drive the duct piece arranged at the tail end of the telescopic pipe to move;

the detection mechanism is positioned in the telescopic pipe, detects the seabed, and determines whether a combustible ice reservoir exists at the detection position by using a computer tomography technology;

the drilling mechanism is positioned in the telescopic pipe, and can change the distance between the drilling mechanism and the seabed through telescopic movement to drive the tail drill to drill the seabed so as to gasify and release the combustible ice in the reservoir;

the backfill mechanism main body is positioned on the mining platform, the output end penetrates through the telescopic pipe and is positioned in the telescopic pipe, backfill materials can be output into the telescopic pipe, and the drill hole is plugged;

the collecting and storing mechanism is communicated with the telescopic pipe, the gas released by the reservoir is collected through the telescopic pipe and is cooled and stored, negative pressure is formed in the telescopic pipe in the collecting process, the gas releasing speed of the reservoir is improved, and the collecting and storing efficiency is improved.

Specifically, as shown in fig. 2, one end of the extension tube is mounted on the mining platform and communicated with the collecting and storing mechanism, and the other end of the extension tube is in butt joint with the duct piece;

the telescopic pipe is a multi-stage telescopic structure formed by coaxially and slidably matching a plurality of pipe sections, the adjacent pipe sections are sleeved, and a linear motion pair is formed between the pipe sections, wherein in the embodiment, the linear motion pair is a motion structure formed by matching a track with a roller;

the extension and contraction among the pipe sections can be driven by a pipe section motor, and the pipe section motor can drive the roller to rotate, so that the corresponding pipe sections are driven to move along the axial direction by matching with the track to complete the extension and contraction action;

in order to ensure the stable operation of the extension tube, a mechanical arm extends from the mining platform to fix and restrain the extension tube and realize auxiliary clamping.

It should be pointed out that, the polymer waterproof material is filled between the pipe sections, the pipe sections are airtight, the surface of the pipe sections has slight adsorbability, the pipe sections can be well attached to the wall of the mining pipe, and the lubricating agent is coated between the pipe sections and the wall of the mining pipe, so that the cavity of the mining pipe is separated from the outside air, and the pipe sections have good airtightness.

For the arrangement of the internal pipeline, the internal pipeline is reserved according to the requirement and then arranged in the telescopic pipe, the reserved quantity is used as the adaptive extension and shortening quantity before and after the telescopic pipe is extended, and the pipeline is prevented from being broken in the extension process.

For the telescopic pipe, because the uppermost pipe section is provided with the electromagnetic wave CT prospecting device, the drilling mechanism, the backfilling mechanism and the like, the telescopic length is limited, so that the pipe section is arranged at the lower part of the telescopic pipe section to form the telescopic pipe, and the rollers and the tracks are arranged according to the telescopic mode.

When the mining motor is not started, all the rollers are in an unconstrained state and can freely slide, so that mining can sink due to the self-weight action, and when the mining motor is started, the rotation of the rollers is controlled by the mining motor, and the driving retraction is realized.

For the segment structure at the tail end, the segment is coaxially and detachably butted with the end part of the telescopic pipe, and one end of the segment, which is far away from the telescopic pipe, is provided with a circular cutter head;

the annular cutter head is used as one end penetrating into the seabed, the thickness of the pipe piece is reduced, the thin-blade cutter head is formed, the pipe piece can be conveniently inserted into the seabed, and after the end part of the pipe piece is inserted into the seabed, a channel for communicating a reservoir drilling hole with the collecting and storing mechanism is formed by combining the telescopic pipe, so that gas released by the reservoir directly enters the collecting and storing mechanism through the channel, and the overflow and diffusion of the gas are avoided.

For the drilling mechanism, the drilling mechanism is arranged in the telescopic pipe and comprises a drilling motor and a drill bit, the drilling motor is connected with the drill bit through a linear moving pair and can drive the drill bit to rotate and move along the axial direction at the same time so as to change the distance between the drill bit and the seabed;

in addition, because the drilling mechanism is integrally positioned in the telescopic pipe, when the telescopic pipe forms an air inlet pipeline, a sliding support can be configured on the drilling mechanism for facilitating the flow of air;

the drilling mechanism is installed in the telescopic pipe through the sliding support to can be through the sliding support for the flexible pipe removal, the drilling position can be adjusted on the one hand, on the other hand, when carrying out the gas transmission operation, with the drilling mechanism remove to the telescopic pipe in the position of being close to the pipe wall, guarantee gas transportation process's smoothness nature.

The inner wall of the telescopic pipe is provided with a drainage mechanism, the input end of the drainage mechanism is communicated with the inside of the telescopic pipe, the output end of the drainage mechanism penetrates through the wall of the telescopic pipe and extends out of the telescopic pipe, and a detection mechanism is arranged in the telescopic pipe;

the detection mechanism is an electromagnetic wave CT (computed tomography) prospecting device 17, transmits radio waves to a drill hole, and determines whether the combustible ice reservoir layer 4 exists at the position by using a computer tomography technology;

as shown in fig. 3, the initial position of the drilling motor coincides with the electromagnetic wave CT prospecting device, after the drilling operation is completed, the drill pipe contracts, the drilling motor moves to both sides along the track, the electromagnetic wave CT prospecting device is started to survey the drilling position, and if the position is determined to contain a combustible ice reservoir, other operations are performed.

The drainage mechanism is a drainage pump, after the existence of the combustible ice reservoir is determined, the drainage pump 9 is started, seawater enters from the water inlet 8 (in a telescopic mode) and is drained from the drainage outlet 9, after drainage is finished, the drainage pump 9 and the ventilation hole 22 are closed, and the vacuum pump device 21 is started to apply proper negative pressure.

The output end of the backfill grouting mechanism is positioned in the telescopic pipe and faces the segment, the telescopic pipe can drive the segment to move axially and is used as an air inlet pipeline of the collecting and storing mechanism to convey the gas released by the reservoir layer to the collecting and storing mechanism for storage;

the collecting and storing mechanism comprises a collector and a pressure chamber, the input end of the collector is communicated with one end of the telescopic pipe through a pipeline, a vacuum pump is arranged on the pipeline between the collector and the telescopic pipe, and the output end of the collector is communicated with the pressure chamber through a pipeline; one end of the telescopic pipe connected with the vacuum pump is provided with a filter plate, and the drilling mechanism is arranged between the filter plate and the pipe piece;

specifically, with reference to fig. 4, a filter plate 30 (only allowing gas to pass through) is arranged between the vacuum pump and the cavity of the mining duct piece, so as to prevent impurities from entering the vacuum pump and causing blockage;

the collector 23 is communicated with one end of a telescopic pipe through a collector pipeline 33, a vacuum pump is installed on the collector pipeline, a collector valve 24 is arranged on the collector pipeline, the telescopic pipe is provided with a vent hole 22, a vent hole valve 34 is arranged on the vent hole, an exhaust pipe is arranged on the vacuum pump, and the exhaust pipe is matched with an exhaust hole valve 35;

when exhaust hole valve 35 is opened, the vacuum pump can be with outside all gas exhaust device in the device, when exhaust hole valve 35 closed, the vacuum pump can with gas pumping to the gas collector in to the inside negative pressure state that can maintain stable always of exploitation section of jurisdiction and can not let methane gas reveal.

The expansion pipe is matched with the pipe piece to establish a communication relation between the combustible ice reservoir and the mining platform, the expansion pipe and the pipe piece are used as gas inlet pipelines to guide gas released by the reservoir to the collecting and storing mechanism and then store the gas, so that a safe mining process is completed, compared with a traditional mining method, the method can be carried out more conveniently and safely, and the treatment process of the gas after mining is reduced;

the equipment has strong leakproofness, gas leakage can be effectively avoided, the adopted equipment and method have no destructive influence on marine ecological environment, the cost is reduced, and the functions of exploration and backfill are realized.

Example 2

In another exemplary embodiment of the present disclosure, as shown in fig. 1 to 4, a method for backfilling and excavating combustible ice at sea is provided, which uses the device for backfilling and excavating combustible ice at sea as described in example 1.

The method comprises the following steps:

when the duct piece is driven to be lowered, the water body drawn out of the extension pipe is discharged to the outside, so that pressure difference is formed inside the extension pipe, the extension pipe and the duct piece gradually sink to the seabed in combination with the self-weight action, the end part of the duct piece is inserted into the surface layer of the seabed, and water in the extension pipe is drained;

when gas decomposed by the combustible ice is collected, the collecting and storing mechanism operates and maintains negative pressure in the telescopic pipe to guide the combustible ice reservoir to release the gas;

Specifically, the mining, excavating and backfilling method in the embodiment is described in detail with reference to the accompanying drawings:

opening the mechanical arm 12, starting the drainage pump 10 (the drainage rate is greater than the water inflow rate of the mining pipe orifice), discharging seawater inside the telescopic pipe (segmented pipe piece and telescopic) outwards (pressure difference is formed between the inside and the outside of the mining pipe piece), slowly sinking the telescopic pipe under the action of self weight and the pressure difference, closing the drainage pump 10 after the circular cutter head 5 is inserted into the seabed surface layer 3, and opening the vent hole 22;

starting a drill motor 15, drilling a hole by using the solid drill 7 (the drill pipe 11 can be stretched up and down), after the hole is drilled, shrinking the drill pipe 11, and moving the drill motor 15 to the edge of the pipe wall of the stretching pipe along a track 16;

starting an electromagnetic wave CT (computed tomography) prospecting device 17, transmitting radio waves to a drill hole, and determining whether the combustible ice reservoir layer 4 exists at the position by using a computer tomography technology;

after the combustible ice storage layer 4 is determined to exist, starting a drainage pump 9, enabling seawater to enter from a water inlet 8 (in a telescopic manner) and be discharged from a drainage port 9, closing the drainage pump 9 and a ventilation hole 22 after the drainage is finished, starting a vacuum pump device 21 to apply proper negative pressure, enabling the interior of a telescopic pipe to be in a vacuum state, slowly inserting the telescopic pipe into the combustible ice storage layer under the action of an internal and external pressure difference, and starting a segment motor 18 to fix the telescopic pipe to enable the telescopic pipe not to stretch and move any more after a certain depth;

starting a drill bit motor 15 to destroy the seabed surface layer 3 until the combustible ice reservoir 4 is exposed;

the exposed part of the combustible ice reservoir 4 is under the action of negative pressure, and the balance state is firstly broken, so that the combustible ice is induced to be continuously decomposed;

the methane gas rises along the annular space of the telescopic pipe under the action of negative pressure, is purified by the filter plate 31 and then enters the gas collector 23;

starting the refrigerating machine 26 and the constant-temperature pressure chamber 25, controlling the temperature and the pressure within the range of liquefying the methane gas, opening the valve 27, and starting liquefying the methane gas and storing the liquefied methane gas in the constant-temperature pressure chamber 25;

after mining, closing the valve 27, closing the vacuum pump device 21, closing the electromagnetic wave CT prospecting device 17, opening the vent hole 22, opening the backfill valve 20, and starting the pumping machine 14 to backfill the mined geological formation through the backfill pipeline 13;

the backfill material is tightly attached to the segment to form a buckling structure, a stable plugging structure can be formed after the other end of the segment is inserted into the seabed, and the segment is discarded;

starting a segment motor 18, slowly contracting the telescopic pipe while backfilling, and closing the pumping machine 14 and the valve 20 after backfilling is finished;

the ring cutter head 5 enters the seawater layer 2, and the telescopic pipe slowly shrinks under the action of the pipe piece motor 18.

After the contraction is finished, the mechanical arm 12 is started to fix the telescopic pipe, and the whole process of combustible ice mining is completed.

the mining area can be well plugged after the disposable segment is filled with the backfill material, the backfill material is combined with the segment to form a buckling structure, and a stable plugging structure can be formed after the other end of the segment is inserted into a seabed.

The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure, and various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A marine combustible ice mining, digging and backfilling device is characterized by comprising a mining platform, a telescopic pipe, a drilling mechanism, a backfilling mechanism and a collecting and storing mechanism, wherein one end of the telescopic pipe is installed on the mining platform and is communicated with the collecting and storing mechanism, the other end of the telescopic pipe is in butt joint with a duct piece, the drilling mechanism is installed in the telescopic pipe, the output end of the backfilling and grouting mechanism is located in the telescopic pipe and faces the duct piece, the telescopic pipe can drive the duct piece to move axially, and the gas released from a reservoir layer is conveyed to the collecting and storing mechanism to be stored as an air inlet pipeline of the collecting and storing mechanism;

the segment is coaxially and detachably butted with the end part of the telescopic pipe, and one end of the segment, which is far away from the telescopic pipe, is provided with a circular cutter head;

the backfill mechanism is arranged on the mining platform and is communicated with the interior of the telescopic pipe through a backfill pipeline to form an output end of the backfill mechanism, and the backfill mechanism is used for inputting backfill materials to be matched with the segments to block the gas release port of the reservoir.

2. The offshore combustible ice mining, backfilling device of claim 1, wherein the drilling mechanism comprises a drilling motor and a drill bit, the drilling motor is connected with the drill bit through a linear moving pair, and the drill bit can be driven to rotate and move along the axial direction at the same time so as to change the distance between the drill bit and the seabed.

3. The offshore combustible ice mining, backfilling device according to claim 1, wherein a drainage mechanism is mounted on the inner wall of the telescopic pipe, the input end of the drainage mechanism is communicated with the inside of the telescopic pipe, the output end of the drainage mechanism passes through the wall of the telescopic pipe and extends out of the telescopic pipe, and a detection mechanism is arranged in the telescopic pipe.

4. The offshore combustible ice mining, backfilling device according to claim 1, wherein the collecting and storing mechanism comprises a collector and a pressure chamber, the input end of the collector is communicated with one end of the telescopic pipe through a pipeline, a vacuum pump is arranged on the pipeline between the collector and the telescopic pipe, and the output end of the collector is communicated with the pressure chamber through a pipeline.

5. The offshore combustible ice mining, backfilling device according to claim 4, wherein one end of the telescopic pipe connected with the vacuum pump is provided with a filter plate, and the drilling mechanism is arranged between the filter plate and the pipe piece.

6. An offshore combustible ice mining and backfilling method by using the offshore combustible ice mining and backfilling device of any one of claims 1-5, which comprises the following steps:

the drilling mechanism is lowered, the seabed is drilled until the reservoir stratum is reached to destroy the phase equilibrium state in the reservoir stratum, and the drilling mechanism is withdrawn;

7. The offshore combustible ice mining, backfilling method according to claim 6, wherein when the flexible pipe piece is lowered, the water body pumped out of the telescopic pipe is discharged to the outside, so that the inside and the outside of the telescopic pipe form a pressure difference, and the telescopic pipe and the pipe piece are gradually sunk to the seabed in combination with the self-weight action.

8. The offshore combustible ice mining backfill method according to claim 6, wherein when collecting gas generated by decomposition of the combustible ice, the collecting and storing mechanism operates and maintains negative pressure in the telescopic pipe to guide the combustible ice reservoir to release the gas.