阅读说明：本技术 一种辅助高压水致裂煤体的干冰封存装置及控制方法 (Dry ice sealing device for assisting high-pressure water fracturing coal body and control method ) 是由 张春华 胡威 于 2020-08-20 设计创作，主要内容包括：本发明提供了一种辅助高压水致裂煤体的干冰封存装置及其控制方法,包括多个封存单元,多个封存单元相互排列组成封存装置设置在预设的钻孔,钻孔的入口处通过封孔材料固定有高压水管,通过高压水管向钻孔内注水完成封存装置的使用,封存单元包括保温层外壳、保温层、内胆外壳、出气口压盖、泄压头和进水口单向阀,本发明通过多个封存单元构成封装装置,放置在钻孔内后,可在煤矿井下实施高压水压裂的煤层钻孔内保温封存干冰,防止在高压水致裂钻孔封孔固化时间内干冰气化损失,有效阻止地下水侵入钻孔后提前进入本装置使其泄压失效,本装置保存干冰效果好,自动工作,可有效辅助高压水致裂煤体作用。(The invention provides a dry ice sealing device for assisting high-pressure water fracturing coal and a control method thereof, and the dry ice sealing device comprises a plurality of sealing units, wherein the plurality of sealing units are mutually arranged to form a sealing device arranged in a preset drill hole, a high-pressure water pipe is fixed at the inlet of the drill hole through a hole sealing material, water is injected into the drill hole through the high-pressure water pipe to finish the use of the sealing device, and the sealing device comprises a heat-insulating layer shell, a heat-insulating layer, an inner container shell, an air outlet gland, a pressure relief head and a water inlet one-way valve. The automatic working can effectively assist the coal body cracking effect caused by high-pressure water.)

1. The utility model provides an supplementary high pressure water sends dry ice sealing device who splits coal body, includes a plurality of sealing units (17), its characterized in that: the sealing units (17) are mutually arranged to form a sealing device arranged in a preset drill hole (16), a high-pressure water pipe (14) is fixed at an inlet of the drill hole (16) through a sealing material (15), and water is injected into the drill hole (16) through the high-pressure water pipe (14) to finish the use of the sealing device;

the sealing unit (17) comprises a heat-insulating layer shell (1), a heat-insulating layer (3), a liner shell (4), an air outlet gland (5), a pressure relief head (7) and a water inlet one-way valve (9), wherein the heat-insulating layer (3) is arranged inside the heat-insulating layer shell (1), the liner shell (4) is arranged inside the heat-insulating layer (3), a liner (12) is arranged inside the liner shell (4), the water inlet one-way valve (9) is fixed at the side end of the liner (12), and the liner shell (4), the heat-insulating layer (3) and the heat-insulating layer shell (1) are all fixed on the outer side of the water inlet one-way valve (9);

the air outlet gland (5) is fixed at the other end of the heat-insulating layer shell (1) and the inner container shell (4), the middle of the air outlet gland (5) is in threaded connection with a pressure relief head (7), and a one-way valve air outlet (8) is arranged in the middle of the pressure relief head (7).

2. The dry ice sealing device for assisting high-pressure water fracturing coal body according to claim 1, wherein the heat insulation layer (3) is filled type pearl sand which is vacuumized.

3. The dry ice sequestration device for assisting high-pressure water fracturing coal body according to claim 1, characterized in that one end of the sequestration unit (17) close to the water inlet check valve (9) is provided with a first gas check valve (2), the inside of the first gas check valve (2) extends to the inside of the heat insulation layer (3), the pressure relief head (7) is provided with a second gas check valve (13), and the inside of the second gas check valve (13) extends to the inside of the pressure relief head (7).

4. The dry ice sealing device for assisting high-pressure water fracturing coal body according to claim 3, wherein the inlets of the first gas check valve (2) and the second gas check valve (13) are respectively provided with a filter screen.

5. The dry ice sealing device for assisting high-pressure water fracturing coal body according to claim 1, wherein the air outlet gland (5) is of a groove hollow cylinder structure, and a thread (6) for threaded connection with the pressure relief head (7) is arranged on the inner side of the groove.

6. The dry ice sealing device for assisting high-pressure water fracturing coal body according to claim 1, wherein a gasket (10) and a constant pressure shear blade (11) are arranged at the joint of the pressure relief head (7) and the air outlet gland (5), and the constant pressure shear blade (11) is set to be a threshold value of 1 MPa.

7. The dry ice sealing device for assisting high-pressure water fracturing coal body according to claim 1, wherein the pressure relief head (7) is of a hollow structure, and the interior of the pressure relief head is filled with pearlife.

8. The dry ice sealing device for assisting high-pressure water fracturing coal body according to claim 1, wherein the liner shell (4) and the heat-insulating layer shell (1) of the sealing unit (17) are of concentric circle structures.

9. The dry ice sealing device for assisting high-pressure water fracturing coal body according to claim 1, wherein the relative vacuum degree of the heat-insulating layer (3) after being vacuumized is-6000 Pa to-3000 Pa.

10. The control method of the dry ice storage device for assisting high-pressure water fracturing coal bodies according to any one of claims 1 to 9, characterized by comprising the following steps:

s1, selecting a proper number of sealing units (17) according to the length of the drilled hole (16), detaching the pressure relief head (7) and the constant pressure shearing sheet (11), filling dry ice in an inner container of the pressure relief head, and sequentially arranging the dry ice end to form a sealing device;

s2, placing the sealing device in the drill hole (16), sealing the inlet of the sealing device by using a sealing material (15), and fixing a high-pressure water pipe (14) communicated with the inlet of the sealing device in the middle of the sealing material (15);

s3, injecting high-pressure water into the drill hole (16) through the high-pressure water pipe (14), and when the pressure in the drill hole (16) reaches the threshold value of the water inlet check valve (9) of 5MPa, allowing the high-pressure water to enter the storage unit (17) through the water inlet check valve (9) and react with dry ice to release carbon dioxide gas and assist in fracturing.

Technical Field

The invention belongs to the technical field of hydraulic fracturing, and particularly relates to a dry ice sealing device for assisting high-pressure water fracturing coal and a control method.

Background

The geological conditions of coal mines in China are complex, and the coal seams generally have the phenomenon of high gas and low gas permeability, so that great challenges are brought to gas disaster prevention and control. In order to increase the high gas and low gas permeability and improve the extraction effect, anti-reflection technologies such as deep-hole explosive blasting, hydraulic punching, hydraulic slotting, liquid carbon dioxide blasting and the like are developed domestically, and various anti-reflection technologies are widely applied to coal mines at present but have the advantages and the disadvantages.

For the high-pressure water fracturing coal body permeability increasing technology, the higher the working pressure of a high-pressure water pump is, the higher the input cost is, and meanwhile, the requirement of ultrahigh-pressure hydraulic fracturing operation on the pressure-bearing performance of a pipeline is strict, and the safety can also be reduced; in addition, in the high-pressure water fracturing process, large-scale new or primary fractures are often encountered in the drill hole, so that the working water pressure is suddenly reduced, and fluctuation is generated. Therefore, the dry ice sealing device and the control method for assisting high-pressure water fracturing coal are provided, the dry ice can be packaged and stored underground, the dry ice can be prevented from invading underground water of a drill hole, a good dry ice sealing effect is achieved, and high-pressure water fracturing is assisted.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a dry ice sealing device and a control method for assisting high-pressure water fracturing coal body to solve the problems proposed in the background art.

In order to solve the technical problems, the invention adopts the technical scheme that: a dry ice sealing device assisting high-pressure water fracturing coal bodies comprises a plurality of sealing units, wherein the sealing units are mutually arranged to form a sealing device arranged in a preset drill hole, a high-pressure water pipe is fixed at an inlet of the drill hole through a hole sealing material, and water is injected into the drill hole through the high-pressure water pipe to finish the use of the sealing device;

the sealing unit comprises a heat preservation layer shell, a heat preservation layer, an inner container shell, an air outlet gland, a pressure relief head and a water inlet one-way valve, wherein the heat preservation layer is arranged inside the heat preservation layer shell;

the gas outlet gland is fixed at the other end of the heat-insulating layer shell and the inner container shell, the middle of the gas outlet gland is in threaded connection with a pressure relief head, and a check valve gas outlet is arranged in the middle of the pressure relief head.

Preferably, the heat-insulating layer is filled pearlife subjected to vacuum-pumping treatment.

Preferably, the one end that the sealing unit is close to the water inlet check valve is provided with first gaseous check valve, the inside of first gaseous check valve extends to the inside of heat preservation, the overhead second gaseous check valve that is provided with of pressure release, the inside of second gaseous check valve extends to the inside of pressure release head.

Preferably, the inlets of the first gas one-way valve and the second gas one-way valve are both provided with a filter screen.

Preferably, the air outlet gland is of a groove hollow cylinder structure, and threads for threaded connection with the pressure relief head are arranged on the inner side of the groove of the air outlet gland.

Preferably, a gasket and a constant pressure shear slice are arranged at the joint of the pressure relief head and the air outlet gland, and the constant pressure shear slice is set to be a threshold value of 1 MPa.

Preferably, the pressure relief head is of a hollow structure, and the interior of the pressure relief head is filled with pearlife.

Preferably, the outer shell of the inner container of the sealing unit and the outer shell of the heat-insulating layer are of concentric circle structures.

Preferably, the relative vacuum degree of the heat-insulating layer after being vacuumized is-6000 Pa to-3000 Pa.

A control method of a dry ice sealing device for assisting high-pressure water fracturing coal bodies comprises the following steps:

s1, selecting a proper number of sealing units according to the length of the drilled hole, detaching the pressure relief head and the constant pressure shearing sheet, filling dry ice in the inner container of the pressure relief head and the constant pressure shearing sheet, and sequentially arranging the dry ice end to form a sealing device;

s2, placing the sealing device in the drill hole, sealing the inlet of the sealing device by using a sealing material, and fixing a high-pressure water pipe communicated with the inlet of the sealing device in the middle of the sealing material;

and S3, injecting high-pressure water into the drill hole through the high-pressure water pipe, and when the pressure in the drill hole reaches the threshold value of the water inlet one-way valve of 5MPa, allowing the high-pressure water to enter the sealing unit through the water inlet one-way valve and react with the dry ice to release carbon dioxide gas and assist in fracturing.

Compared with the prior art, the invention has the following advantages:

the device comprises a plurality of sealing units, wherein the sealing units are arranged in a drill hole, and the sealing units can be used for sealing dry ice in the drill hole of the coal bed for performing high-pressure water fracturing under the coal mine, so that the dry ice is prevented from being gasified and lost in the hole sealing and curing time of the high-pressure water fracturing drill hole, underground water is effectively prevented from entering the device in advance to cause the pressure relief failure after entering the drill hole, and a large amount of gas carbon dioxide is ensured to be quickly released to play an auxiliary role only in performing the high-pressure water fracturing.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a cross-sectional view of the lower sealing unit structure of the present invention

Description of reference numerals:

1-insulating layer shell; 2-a first gas one-way valve; 3, insulating layer; 4-inner container outer shell; 5-air outlet gland bush; 6-thread; 7-pressure relief head; 8-one-way valve air outlet; 9-water inlet check valve; 10-a gasket; 11-cutting into slices under constant pressure; 12-inner container; 13-a second gas check valve; 14-high pressure water pipe; 15-hole sealing material; 16-drilling; 17-a sealing unit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-2, the present invention provides a technical solution: a dry ice sealing device assisting high-pressure water fracturing coal bodies comprises a plurality of sealing units 17, wherein the sealing units 17 are mutually arranged to form a sealing device arranged in a preset drill hole 16, a high-pressure water pipe 14 is fixed at an inlet of the drill hole 16 through a hole sealing material 15, and water is injected into the drill hole 16 through the high-pressure water pipe 14 to finish the use of the sealing device;

the sealing unit 17 comprises a heat-insulating layer shell 1, a heat-insulating layer 3, an inner container shell 4, an air outlet gland 5, a pressure relief head 7 and a water inlet one-way valve 9, wherein the heat-insulating layer 3 is arranged inside the heat-insulating layer shell 1, the heat-insulating layer 3 is filled pearlife subjected to vacuumizing treatment, a first gas one-way valve 2 is arranged at one end, close to the water inlet one-way valve 9, of the sealing unit 17, the inside of the first gas one-way valve 2 extends to the inside of the heat-insulating layer 3, the heat-insulating layer 3 is subjected to vacuumizing treatment through the first gas one-way valve 2, and the relative vacuum degree of the heat-insulating layer 3 is-6000 Pa-3000 Pa after.

The inner container shell 4 is arranged inside the heat insulation layer 3, the inner container 12 is arranged in the inner container shell 4, the inner container shell 4 and the heat insulation layer shell 1 are of concentric circle structures, a water inlet one-way valve 9 is fixed at the side end of the inner container 12, and the inner container shell 4, the heat insulation layer 3 and the heat insulation layer shell 1 are all fixed at the outer side of the water inlet one-way valve 9;

the other end at heat preservation shell 1 and inner bag shell 4 is fixed to gas outlet gland 5, the middle threaded connection of gas outlet gland 5 has pressure release head 7, pressure release head 7's centre is provided with check valve gas outlet 8, gas outlet check valve 8 is used for releasing gaseous carbon dioxide, pressurizes to 1MPa after meeting water reaction the dry ice that loads in inner bag 12, breaks the constant pressure shear section 11, by gas outlet check valve 8 release, gas outlet check valve 8 can only be by the inside outside release gas of device, the outside water of device can't get into inside, prevents that outside water groundwater pressure from destroying constant pressure shear section 11, plays protection constant pressure shear section 11 effect promptly, and pressure release head 7 and gas outlet gland 5 junction still have gasket 10 in addition, also plays sealed effect in addition.

The pressure relief head 7 is of a hollow structure, pearlife is filled in the pressure relief head 7, a second gas one-way valve 13 is arranged on the pressure relief head 7, and the inside of the second gas one-way valve 13 extends into the pressure relief head 7 and is used for vacuumizing the inside of the pressure relief head 7.

For convenience of use, the inlets of the first gas one-way valve 2 and the second gas one-way valve 13 are provided with filter screens.

The gas outlet gland 5 is a hollow cylinder structure with a groove, a thread 6 for connecting the pressure relief head 7 with the thread is arranged on the inner side of the groove, a gasket 10 and a constant pressure shearing sheet 11 are arranged at the joint of the pressure relief head 7 and the gas outlet gland 5, and the constant pressure shearing sheet 11 is set to be a threshold value of 1 MPa.

The inner container shell 4 is made of a low-temperature pressure container steel plate 16MnDR, the heat-insulating layer shell 1 is made of a pressure container steel plate Q345R, and the air outlet gland 5 is made of a low-temperature pressure container steel plate 16 MnDR.

A control method of a dry ice sealing device for assisting high-pressure water fracturing coal bodies comprises the following steps:

s1, selecting a proper number of sealing units 17 according to the length of the drilled hole 16, firstly detaching the pressure relief head 7 and the constant pressure shearing sheet 11, then filling dry ice into the liner, then connecting the constant pressure shearing sheet 11 and the pressure relief head 7 on the sealing units 17 through threads, and sequentially arranging the sealing units to form a sealing device;

s2, placing the sealing device in the drill hole 16, sealing the inlet of the sealing device by using a sealing material 15, and fixing a high-pressure water pipe 14 communicated with the inlet of the sealing device in the middle of the sealing material 15;

s3, injecting high-pressure water into the drill hole 16 through the high-pressure water pipe 14, and when the pressure in the drill hole 16 reaches the threshold value 5MPa of the water inlet one-way valve 9, allowing the high-pressure water to enter the sealing unit 17 through the water inlet one-way valve 9 and react with dry ice to release carbon dioxide gas and assist in fracturing.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.