阅读说明：本技术 一种模拟二氧化碳置换法开采天然气水合物的系统 (System for simulating carbon dioxide displacement method to exploit natural gas hydrate ) 是由 荆铁亚 赵文韬 张健 王金意 郜时旺 于 2019-11-15 设计创作，主要内容包括：本发明公开了一种模拟二氧化碳置换法开采天然气水合物的系统,包括反应釜、加压活塞、加压泵、压力传感器、储液罐、抽液泵、第一阀门、CH<Sub>4</Sub>气瓶、第二阀门、抽气泵、CO<Sub>2</Sub>气瓶、第三阀门、第一流量计、第四阀门、第五阀门、废液罐、注气管、真空泵、第六阀门、第二流量计、第一导管、试剂容器、第二导管、第三流量计、第七阀门、排气管、电子天平及恒温箱,该系统能够在实验室中模拟二氧化碳置换法开采天然气水合物。(The invention discloses a system for exploiting natural gas hydrate by simulating a carbon dioxide displacement method, which comprises a reaction kettle, a pressurizing piston, a pressurizing pump, a pressure sensor, a liquid storage tank, a liquid pumping pump, a first valve, CH 4 Gas cylinder, second valve, air pump, CO 2 The system comprises a gas cylinder, a third valve, a first flowmeter, a fourth valve, a fifth valve, a waste liquid tank, a gas injection pipe, a vacuum pump, a sixth valve, a second flowmeter, a first conduit, a reagent container, a second conduit, a third flowmeter, a seventh valve, an exhaust pipe, an electronic balance and a thermostat, and can be used for exploiting natural gas hydrates by simulating a carbon dioxide displacement method in a laboratory.)

1. The system for exploiting the natural gas hydrate by the simulated carbon dioxide displacement method is characterized by comprising a reaction kettle (9), a pressurizing piston (14), a pressurizing pump (10), a pressure sensor (12), a liquid storage tank (1), a liquid pumping pump (3), a first valve (6), and CH₄A gas cylinder (22), a second valve (23), an air pump (29), CO₂A gas cylinder (25), a third valve (26), a first flowmeter (27), a fourth valve (31), a fifth valve (18), a waste liquid tank (21), a gas injection pipe (32), a vacuum pump (15), a sixth valve (34), a second flowmeter (35), a first conduit (36),A reagent container (37), a second conduit (38), a third flow meter (39), a seventh valve (40), an exhaust pipe (41), an electronic balance (42) and a thermostat (33);

the bottom of the reaction kettle (9) is filled with transparent glass balls (17), a pressurizing piston (14) is positioned in the reaction kettle (9), and an output shaft of a pressurizing pump (10) is connected with the pressurizing piston (14) through a pressure sensor (12);

the outlet of the liquid storage tank (1) is communicated with the water inlet of the reaction kettle (9) through the liquid pump (3) and the first valve (6);

CH₄the outlet of the gas cylinder (22) is communicated with the inlet of a suction pump (29) through a second valve (23), and CO₂An outlet of the gas cylinder (25) is communicated with an inlet of a suction pump (29) through a third valve (26) and a first flowmeter (27), an outlet of the suction pump (29) is communicated with one end of a fourth valve (31), one end of a fifth valve (18) is communicated with an inlet of a waste liquid tank (21), the lower end of a gas injection pipe (32) is communicated with the other end of the fifth valve (18) and the other end of the fourth valve (31), the upper end of the gas injection pipe (32) is inserted into the reaction kettle (9) from the bottom of the reaction kettle (9), and the side surface of the part, positioned in the reaction kettle (9), of the gas injection pipe (32) is provided with a plurality of through holes;

an air outlet at the top of the reaction kettle (9) is communicated with a vacuum pump (15) and one end of a sixth valve (34), the other end of the sixth valve (34) is communicated with one end of a first conduit (36) through a second flow meter (35), the other end of the first conduit (36) is inserted into a reagent container (37), and an exhaust port at the top of the reagent container (37) is communicated with an exhaust pipe (41) through a second conduit (38), a third flow meter (39) and a seventh valve (40);

the reagent container (37) is positioned on an electronic balance (42), and the reaction kettle (9) is positioned in the constant temperature box (33).

2. The system for exploiting natural gas hydrates by simulating carbon dioxide displacement according to claim 1, wherein an output shaft of the pressurizing pump (10) is connected with the pressurizing piston (14) through the first metal rod (11), the pressure sensor (12) and the second metal rod (13).

3. The system for exploiting natural gas hydrates by simulating carbon dioxide displacement method according to claim 1, further comprising a third conduit (2), wherein one end of the third conduit (2) is inserted into the liquid storage tank (1), and the other end of the third conduit (2) is communicated with the water inlet of the reaction kettle (9) through the liquid pump (3), the fourth conduit (4), the fourth flowmeter (5), the first valve (6) and the fifth conduit (7) in sequence.

4. The system for exploiting natural gas hydrates by simulating the carbon dioxide displacement method according to claim 3, characterized in that a pressure stabilizing valve (8) is arranged on the fifth conduit (7).

5. The system for exploiting natural gas hydrates by simulating carbon dioxide displacement method according to claim 3, characterized in that the gas outlet of the reaction kettle (9) is communicated with the vacuum pump (15) and the sixth valve (34) through a sixth conduit (16).

6. The system for producing natural gas hydrates by simulated carbon dioxide displacement method according to claim 5, further comprising a seventh conduit (28), wherein CO is contained in₂The outlet of the gas cylinder (25) is communicated with one end of a seventh conduit (28) through a third valve (26) and a first flowmeter (27), CH₄The outlet of the gas cylinder (22) is communicated with a seventh conduit (28) through a second valve (23) and a fifth flowmeter (24) in sequence, and the other end of the seventh conduit (28) is communicated with the inlet of a suction pump (29).

7. The system for exploiting natural gas hydrates by simulated carbon dioxide displacement method according to claim 6, characterized in that the outlet of the air pump (29) is communicated with the fourth valve (31) through an eighth conduit (30).

8. The system for exploiting natural gas hydrates by simulating carbon dioxide displacement according to claim 7, further comprising a liquid discharge pipe (20) and a ninth conduit (19), wherein one end of the ninth conduit (19) is communicated with the fifth valve (18), the other end of the ninth conduit (19) is communicated with the upper end of the liquid discharge pipe (20), and the lower end of the liquid discharge pipe (20) is inserted into the waste liquid tank (21).

9. The system for exploiting natural gas hydrates by simulating the carbon dioxide displacement method according to claim 1, wherein the liquid storage tank (1) is filled with distilled water, and the distance between the liquid level of the distilled water and the top opening of the liquid storage tank (1) is 1/4 of the height of the liquid storage tank (1).

10. The system for exploiting natural gas hydrates by simulating the carbon dioxide displacement method according to claim 1, wherein an observation window is arranged on the side wall of the reaction kettle (9).

Technical Field

The invention belongs to the technical field of natural gas hydrate development simulation, and relates to a system for exploiting natural gas hydrate by a simulated carbon dioxide displacement method.

Background

The natural gas hydrate is a potential energy source with huge value, and the energy shortage can be effectively relieved by successful exploitation and utilization. China has successfully carried out continuous extraction in south China. CO 2₂As greenhouse gases, large-scale emission causes serious environmental destruction, resulting in increased air temperature and sea level. By CO₂The replacement of natural water hydrate and the permanent sealing of carbon dioxide hydrate in the seabed are feasible for reducing CO₂A method of venting. CO 2₂The advantages of displacing natural gas hydrates are: when CO is present₂Substitution of CH₄And form natural gas hydrate, on the one hand, CO is reduced₂On the other hand, the stability of the seabed hydrate deposit layer is maintained, and the method has environmental protection value and economic value.

The formation of natural gas hydrates and carbon dioxide hydrates requires certain conditions of temperature, pressure, gas source and the like. Under certain temperature conditions, the pressure required for the natural gas hydrate to be stable is higher than that of the carbon dioxide hydrate. Thus, within a particular pressure range, natural gas hydrates will decompose, while carbon dioxide hydrates will tend to form and remain stable. If CO is injected into the natural gas hydrate reservoir at this point₂Gas, CO₂The gas may react with water from the dissociation of the natural gas hydrate to form carbon dioxide hydrate. The heat released by this action allows the decomposition reaction of the natural gas hydrate to proceed continuously. With respect to CO₂The efficiency and the process of replacing the natural gas hydrate are not quantitatively evaluated at present, and CO₂The influence factors of the replacement of the natural gas hydrate are not clear enough, and related simulation equipment is lacked.

Therefore, there is a need for a device and a system for exploiting natural gas hydrate by a laboratory simulation carbon dioxide displacement method.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a system for simulating a carbon dioxide displacement method to produce natural gas hydrate, which can simulate the carbon dioxide displacement method to produce natural gas hydrate in a laboratory.

In order to achieve the purpose, the system for exploiting the natural gas hydrate by the simulated carbon dioxide displacement method comprises a reaction kettle, a pressurizing piston, a pressurizing pump, a pressure sensor, a liquid storage tank, a liquid pumping pump, a first valve, a CH₄Gas cylinder, second valve, air pump, CO₂The device comprises a gas cylinder, a third valve, a first flowmeter, a fourth valve, a fifth valve, a waste liquid tank, a gas injection pipe, a vacuum pump, a sixth valve, a second flowmeter, a first conduit, a reagent container, a second conduit, a third flowmeter, a seventh valve, an exhaust pipe, an electronic balance and a thermostat;

the bottom of the reaction kettle is filled with transparent glass balls, the pressurizing piston is positioned in the reaction kettle, and an output shaft of the pressurizing pump is connected with the pressurizing piston through a pressure sensor;

the outlet of the liquid storage tank is communicated with the water inlet of the reaction kettle through a liquid pump and a first valve;

CH₄the outlet of the gas cylinder is communicated with the inlet of the air pump through a second valve, and CO is₂The outlet of the gas cylinder is communicated with the inlet of the air pump through a third valve and a first flowmeter, the outlet of the air pump is communicated with one end of a fourth valve, one end of a fifth valve is communicated with the inlet of the waste liquid tank, the lower end of a gas injection pipe is communicated with the other end of the fifth valve and the other end of the fourth valve, the upper end of the gas injection pipe is inserted into the reaction kettle from the bottom of the reaction kettle, and the side surface of the part, positioned in the reaction kettle, of the gas injection pipe is provided with a plurality of through holes;

an air outlet at the top of the reaction kettle is communicated with a vacuum pump and one end of a sixth valve, the other end of the sixth valve is communicated with one end of a first conduit through a second flow meter, the other end of the first conduit is inserted into a reagent container, and an air outlet at the top of the reagent container is communicated with an exhaust pipe through the second conduit, a third flow meter and a seventh valve;

the reagent container is positioned on the electronic balance, and the reaction kettle is positioned in the constant temperature box.

The output shaft of the pressure pump is connected with the pressure piston through a first metal rod, a pressure sensor and a second metal rod.

The device also comprises a third conduit, wherein one end of the third conduit is inserted into the liquid storage tank, and the other end of the third conduit is communicated with the water inlet of the reaction kettle sequentially through the liquid pump, the fourth conduit, the fourth flowmeter, the first valve and the fifth conduit.

And a pressure stabilizing valve is arranged on the fifth guide pipe.

The gas outlet of the reaction kettle is communicated with the vacuum pump and the sixth valve through a sixth conduit.

Further comprises a seventh conduit, wherein CO₂The outlet of the gas cylinder is communicated with one end of a seventh conduit through a third valve and a first flowmeter, CH₄The outlet of the gas cylinder is communicated with a seventh conduit through a second valve and a fifth flowmeter in sequence, and the other end of the seventh conduit is communicated with the inlet of the air extracting pump.

The outlet of the air pump is communicated with the fourth valve through an eighth conduit.

The device also comprises a liquid discharge pipe and a ninth conduit, wherein one end of the ninth conduit is communicated with the fifth valve, the other end of the ninth conduit is communicated with the upper end of the liquid discharge pipe, and the lower end of the liquid discharge pipe is inserted into the waste liquid tank.

The liquid storage tank is filled with distilled water, and the distance between the liquid level of the distilled water and the top opening of the liquid storage tank is 1/4 of the height of the liquid storage tank.

An observation window is arranged on the side wall of the reaction kettle.

The invention has the following beneficial effects:

during the concrete operation of the system for exploiting the natural gas hydrate by the simulated carbon dioxide displacement method, the vacuum pump, the thermostat and the transparent glass ball are utilized to simulate the environment required by the formation of the natural gas hydrate, and CH is injected into the reaction kettle₄Gas and water to generate natural gas hydrate in the reaction kettle, and then injecting CO into the reaction kettle₂Gas, by CO₂Replacing natural gas hydrate with gas according to the generation amount of natural gas hydrate and CO₂Calculating the replacement efficiency of the carbon dioxide by using the replacement amount so as to realize the exploitation of the natural gas hydrate by simulating the carbon dioxide replacement method in a laboratoryThe purpose of (2) is simple structure and convenient operation.

Drawings

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

Wherein, 1 is a liquid storage tank, 2 is a third conduit, 3 is a liquid pump, 4 is a fourth conduit, 5 is a fourth flowmeter, 6 is a first valve, 7 is a fifth conduit, 8 is a pressure stabilizing valve, 9 is a reaction kettle, 10 is a pressure pump, 11 is a first metal rod, 12 is a pressure sensor, 13 is a second metal rod, 14 is a pressure piston, 15 is a vacuum pump, 16 is a sixth conduit, 17 is a transparent glass ball, 18 is a fifth valve, 19 is a ninth conduit, 20 is a liquid discharge pipe, 21 is a waste liquid tank, 22 is CH₄A gas cylinder, a second valve 23, a fifth flowmeter 24 and CO 25₂The gas cylinder, 26 is a third valve, 27 is a first flowmeter, 28 is a seventh conduit, 29 is an air pump, 30 is an eighth conduit, 31 is a fourth valve, 32 is an air injection pipe, 33 is an incubator, 34 is a sixth valve, 35 is a second flowmeter, 36 is a first conduit, 37 is a reagent container, 38 is a second conduit, 39 is a third flowmeter, 40 is a seventh valve, 41 is an exhaust pipe, and 42 is an electronic balance.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, the system for exploiting natural gas hydrate by simulating carbon dioxide displacement method according to the invention comprises a reaction kettle 9, a pressurizing piston 14, a pressurizing pump 10, a pressure sensor 12, a liquid storage tank 1, a liquid pumping pump 3, a first valve 6, a CH₄Gas cylinder 22, second valve 23, air pump 29, CO₂A gas cylinder 25, a third valve 26, a first flowmeter 27, a fourth valve 31, a fifth valve 18, a waste liquid tank 21, a gas injection pipe 32, a vacuum pump 15, a sixth valve 34, a second flowmeter 35, a first conduit 36, a reagent container 37, a second conduit 38, a third flowmeter 39, a seventh valve 40, an exhaust pipe 41, an electronic balance 42, and an incubator 33; the bottom of the reaction kettle 9 is filled with transparent glass balls 17, a pressurizing piston 14 is positioned in the reaction kettle 9, and an output shaft of a pressurizing pump 10 is connected with the pressurizing piston 14 through a pressure sensor 12; the outlet of the liquid storage tank 1 is communicated with the water inlet of the reaction kettle 9 through a liquid pump 3 and a first valve 6; CH (CH)₄The outlet of the gas cylinder 22 is connected via a second valve 23 to the inlet of a suction pump 29, the outlet of the suction pump 29 is connected via an eighth conduit 30 to a fourth valve 31, and CO₂The outlet of the gas cylinder 25 is communicated with the inlet of the air pump 29 through the third valve 26 and the first flowmeter 27, the outlet of the air pump 29 is communicated with one end of the fourth valve 31, one end of the fifth valve 18 is communicated with the inlet of the waste liquid tank 21, the lower end of the gas injection pipe 32 is communicated with the other end of the fifth valve 18 and the other end of the fourth valve 31, the upper end of the gas injection pipe 32 is inserted into the reaction kettle 9 from the bottom of the reaction kettle 9, and the side surface of the part of the gas injection pipe 32 positioned in the reaction kettle 9 is provided with a plurality of through holes; an air outlet at the top of the reaction kettle 9 is communicated with one end of the vacuum pump 15 and one end of a sixth valve 34, the other end of the sixth valve 34 is communicated with one end of a first conduit 36 through a second flow meter 35, the other end of the first conduit 36 is inserted into a reagent container 37, and an air outlet at the top of the reagent container 37 is communicated with an exhaust pipe 41 through a second conduit 38, a third flow meter 39 and a seventh valve 40.

The reagent container 37 is placed on an electronic balance 42, and the reaction vessel 9 is placed in an incubator 33.

Specifically, the output shaft of the pressure pump 10 is connected to a pressure piston 14 via a first metal rod 11, a pressure sensor 12, and a second metal rod 13.

The invention also comprises a third guide pipe 2, wherein one end of the third guide pipe 2 is inserted into the liquid storage tank 1, the other end of the third guide pipe 2 is communicated with a water inlet of the reaction kettle 9 through a liquid pump 3, a fourth guide pipe 4, a fourth flowmeter 5, a first valve 6 and a fifth guide pipe 7 in sequence, and a pressure stabilizing valve 8 is arranged on the fifth guide pipe 7.

The air outlet of the reaction kettle 9 is communicated with a vacuum pump 15 and a sixth valve 34 through a sixth conduit 16; the invention also comprises a seventh conduit 28, wherein CO₂The outlet of the gas cylinder 25 is connected to one end of a seventh conduit 28, CH, via a third valve 26 and a first flow meter 27₄The outlet of the gas cylinder 22 is connected to a seventh conduit 28 via a second valve 23 and a fifth flow meter 24, and the other end of the seventh conduit 28 is connected to the inlet of a suction pump 29.

The invention also comprises a drain pipe 20 and a ninth conduit 19, wherein one end of the ninth conduit 19 is communicated with the fifth valve 18, the other end of the ninth conduit 19 is communicated with the upper end of the drain pipe 20, and the lower end of the drain pipe 20 is inserted into the waste liquid tank 21.

The liquid storage tank 1 is filled with distilled water, and the distance between the liquid level of the distilled water and the top opening of the liquid storage tank 1 is 1/4 of the height of the liquid storage tank 1; be provided with the observation window on reation kettle 9's the lateral wall, thermostated container 33 is transparent high pressure resistant material to observe the experiment progress.

The measuring ranges of the first flowmeter 27, the second flowmeter 35, the third flowmeter 39, the fourth flowmeter 5 and the fifth flowmeter 24 are all 1000ml/min, the precision is all 0.1ml/min, and the pressure resistance is all 50 MPa.

Transparent glass balls 17 with different diameters can be filled in the bottom of the reaction kettle 9 to simulate different stratums and facilitate observation, and the transparent glass balls are arranged according to geological conditions of the stratums.

The measuring range of the pressure sensor 12 is 0-50MPa, and the measuring precision is 0.1 MPa.

The drain pipe 20 extends into the bottom of the waste liquid tank 21 to prevent the waste liquid from splashing and polluting.

The pressure stabilizing valve 8 can stabilize the pressure in the reaction kettle 9 and prevent the pressure in the reaction kettle 9 from being overlarge, and the pressure stabilizing range of the pressure stabilizing valve 8 is 0-50 MPa.

The reagent vessel 37 is filled with an excess of lime water solution to ensure CO in the mixed gas₂Is completely absorbed.

The measuring range of the electronic balance 42 is 0.00-3000.00g, and the measuring precision is 0.01 g.

The specific working process of the invention is as follows:

1) putting transparent glass balls 17 with different diameters at the bottom of a reaction kettle 9, and setting the temperature of a constant temperature box 33 at 0-10 ℃ as required;

2) the inside of the reaction kettle 9 is brought into a vacuum state by a vacuum pump 15;

3) opening the first valve 6 and the liquid pump 3, and injecting distilled water into the reaction kettle 9;

4) pressurizing the reaction kettle 9 by a pressurizing pump 10 according to the experimental design, so that the pressure in the reaction kettle 9 is kept within the experimental design pressure range and is kept stable;

5) according to the experimental design, the second valve 23 and the fourth valve 31 are opened, and the air pump 29 is used for slowly injecting CH into the reaction kettle 9₄Gas, observing the experimental reaction through the observation window, so that natural gas hydrate is generated in the reaction kettle 9, and calculating the generation amount of the natural gas hydrate according to the reading of the fifth flowmeter 24;

6) closing all pumps and valves;

7) placing the reagent container 37 with excess lime water solution on the electronic balance 42 and zeroing the electronic balance 42;

8) the third valve 26, the fourth valve 31, the sixth valve 34 and the seventh valve 40 are opened, and CO is slowly injected into the reaction kettle 9 by using the air pump 29₂A gas;

9) after the experiment is carried out for a period of time, the air pump 29, the third valve 26 and the fourth valve 31 are closed, and the sixth valve 34 and the seventh valve 40 are closed after no reaction exists in the reagent container 37;

10) reading numbers of the first flowmeter 27, the second flowmeter 35, the third flowmeter 39 and the electronic balance 42 are recorded, and CO is calculated according to data measured by the first flowmeter 27, data measured by the second flowmeter 35, data measured by the third flowmeter 39 and data measured by the electronic balance 42₂The amount of substitution;

11) after the experiment is finished, opening the fifth valve 18 to discharge waste liquid, disassembling each experimental instrument of the system, and cleaning pipelines and equipment;

12) according to the formation amount of natural gas hydrate and CO₂The substitution amount was calculated to calculate the efficiency of carbon dioxide substitution.