Apparatus and method for producing methane by microbial anaerobic fermentation under in-situ conditions of coal reservoirs

Abstract

The application discloses a kind of coal reservoir in situ conditions under microbial anaerobic fermentation methane production device, including main pipe, liquid injection pipe and extraction pipe, wherein, the liquid injection pipe is fixedly arranged in the main pipe with extraction pipe, the liquid injection pipe is connected with external biological fracturing fluid tank by pressure pump, the extraction pipe is connected with external extraction mechanism, the input end of the extraction pipe is provided with gas-liquid separation mechanism, the input end of the main pipe is fixedly provided with plugging mechanism, the inside of the main pipe is also provided with adjusting mechanism.

Description

Technical Field

[0001] This invention relates to the field of microbial methane production technology, specifically to an apparatus and method for producing methane through anaerobic fermentation of microorganisms under in-situ conditions in coal reservoirs. Background Technology

[0002] Anaerobic fermentation technology involves injecting selected, domesticated, and improved microbial strains into underground coal seams. Through anaerobic fermentation, some of the organic components of the coal are converted into methane, thereby achieving the dual goals of increasing methane production and reducing carbon emissions. Its principle is mainly based on the use of microorganisms to decompose organic matter to produce methane or convert carbon dioxide into methane under anaerobic conditions.

[0003] Currently, devices for in-situ anaerobic fermentation of microorganisms to increase methane production in coal seams typically involve directly injecting microbial fracturing fluid into the coal seam. After a long period of fermentation, methane is extracted using extraction equipment. However, microbial fermentation generates significant amounts of wastewater, which can pollute the environment. Simple extraction is prone to extracting wastewater, making subsequent methane treatment inconvenient. This results in a cumbersome extraction process, slow extraction speed, and low purity of the extracted methane after mixing with wastewater.

[0004] Therefore, it is necessary to provide an apparatus and method for producing methane by microbial anaerobic fermentation under in-situ conditions in coal reservoirs, in order to solve the problems mentioned in the background art. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides the following technical solution: a methane production device for microbial anaerobic fermentation under in-situ conditions in a coal reservoir, comprising a main pipe, an injection pipe, and an extraction pipe, wherein the injection pipe and the extraction pipe are fixedly disposed inside the main pipe, the injection pipe is connected to an external bio-fracturing fluid tank via a pressurization pump, and the extraction pipe is connected to an external extraction mechanism;

[0006] The input end of the extraction pipe is equipped with a gas-liquid separation mechanism;

[0007] The main input end is fixedly equipped with a blocking mechanism, and the main body is also equipped with an adjustment mechanism.

[0008] Preferably, the main pipe is provided with multiple injection holes and extraction holes;

[0009] The injection hole is connected to the injection pipe, and the extraction hole is connected to the extraction pipe.

[0010] Preferably, the adjustment mechanism includes an adjustment seat and an adjustment plate, wherein the adjustment seat is rotatably disposed at the input end of the main pipe, and the adjustment plate is arc-shaped and fixedly disposed on the adjustment seat;

[0011] The regulating plate has multiple through holes one and through holes two, wherein through hole one is the same size as the injection hole, through hole two is the same size as the extraction hole, and through hole one and through hole two are set at different positions;

[0012] Furthermore, the adjusting plate is rotatably and sealingly arranged along the inner wall of the main pipe.

[0013] Preferably, the gas-liquid separation mechanism includes a storage tank, a filter plate, and a level gauge. The storage tank is fixedly mounted on the main pipe and is connected to the extraction pipe. The filter plate is obliquely fixedly mounted in the storage tank, and a level gauge is fixedly mounted on the storage tank.

[0014] Preferably, a discharge mechanism is also provided on the side of the liquid storage tank;

[0015] The discharge mechanism includes a discharge seat and a discharge plate. The discharge seat is fixedly disposed on the side of the liquid storage tank and has a discharge cavity. The discharge plate is rotatably disposed in the discharge cavity and has multiple discharge slots spaced apart on the discharge plate.

[0016] The discharge chamber has two discharge holes on its upper and lower sides. The upper discharge hole is connected to the output end of the filter plate, and the lower discharge hole is connected to the outside of the discharge chamber.

[0017] Preferably, the sealing mechanism includes a sealing seat, a sealing gasket, and an airbag, wherein the sealing seat is fixedly disposed on the main pipe, the sealing gasket is fixedly disposed on the sealing seat and extends to the output end of the main pipe, and an airbag is disposed between the sealing gasket and the sealing seat.

[0018] A method for producing methane through in-situ microbial anaerobic fermentation under coal reservoir conditions includes the following steps:

[0019] S1. Drill an inclined hole using a drilling rig, insert the main pipe into the hole and fix it, and then seal the hole using a sealing mechanism;

[0020] S2. Use the adjustment mechanism to seal the extraction hole, open the injection hole, then turn on the pressurization pump to inject liquid CO2 into the coal seam as a pre-fracturing fluid to create fractures, then use bio-fracturing fluid to carry sand for fracturing, and then seal the main pipe.

[0021] S3. After the microorganisms have fully interacted with the dispersed organic matter in the coal reservoir, shale and tight rock, the injection hole is blocked by the adjustment mechanism and the extraction hole is opened, so that the wastewater generated by the anaerobic reaction of the microorganisms flows into the storage tank through the extraction hole.

[0022] S4. The filter plate is used to filter the coal slag in the wastewater. The coal slag enters the discharge mechanism under the action of gravity and is discharged by the discharge mechanism.

[0023] S5. Based on the reading of the level gauge in the storage tank, remove the wastewater from the storage tank;

[0024] S6. After all the wastewater has been removed, use an external extraction device to extract and collect the CH4 generated by the anaerobic reaction of microorganisms.

[0025] Preferably, the anaerobic reaction equation in step S3 is:

[0026] CH3COOH==>CH4+CO2;

[0027] CO2 + 4H2 ==> CH4 + 2H2O.

[0028] Compared with the prior art, the present invention provides an apparatus and method for producing methane by microbial anaerobic fermentation under in-situ conditions in coal reservoirs, which has the following beneficial effects:

[0029] In this invention, a pressurized pump is used to inject liquid CO2 into the coal seam, creating fractures within it. Bio-fracturing fluid carrying sand is then injected, forming gas flow channels within the coal seam. This effectively improves methane production efficiency and facilitates methane extraction. A main pipe is installed, integrating the injection and extraction pipes for easier extraction. An adjustment mechanism ensures that injection and extraction do not interfere with each other. A gas-liquid separation mechanism is installed at the extraction pipe to discharge wastewater generated by microbial fermentation before methane extraction, effectively improving the purity of extracted methane. A filter plate and discharge mechanism are incorporated into the gas-liquid separation mechanism to effectively filter and discharge coal dust particles, further enhancing the purity and speed of methane extraction. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the adjustment mechanism in this invention;

[0032] Figure 3 This is a schematic diagram of the gas-liquid separation mechanism in this invention;

[0033] Figure 4 This is a schematic diagram of the emission mechanism structure in this invention;

[0034] Figure 5 This is a schematic diagram of the sealing mechanism in this invention.

[0035] In the diagram: 1. Main pipe; 11. Injection hole; 12. Extraction hole; 2. Injection pipe; 3. Extraction pipe; 4. Gas-liquid separation mechanism; 41. Storage tank; 42. Filter plate; 43. Level gauge; 44. Discharge mechanism; 441. Discharge seat; 442. Discharge plate; 443. Discharge chamber; 444. Discharge hole; 445. Discharge trough; 5. Sealing mechanism; 51. Sealing seat; 52. Sealing gasket; 53. Airbag; 6. Adjustment mechanism; 61. Adjustment seat; 62. Adjustment plate; 63. Through hole one; 64. Through hole two. Detailed Implementation

[0036] Example: Please refer to Figures 1-5 In this embodiment of the invention, a microbial anaerobic fermentation methane production device under in-situ conditions of a coal reservoir includes a main pipe 1, an injection pipe 2, and an extraction pipe 3. The injection pipe 2 and the extraction pipe 3 are fixedly installed inside the main pipe 1. The injection pipe 2 is connected to an external bio-fracturing fluid tank through a pressure pump, and the extraction pipe 3 is connected to an external extraction mechanism.

[0037] The gas-liquid separation mechanism 4 is provided at the input end of the extraction pipe 3;

[0038] The input end of the main pipe 1 is fixedly equipped with a blocking mechanism 5, and the main pipe 1 is also equipped with an adjustment mechanism 6.

[0039] During implementation, an inclined borehole is drilled using a drilling rig, followed by the insertion of the main pipe 1. The borehole is then sealed using a sealing mechanism 5. The injection port 11 is opened using the regulating mechanism 6, while the extraction port 12 is closed. A pressurized pump then injects liquid CO2 into the coal seam to create fractures. Bio-fracturing fluid carrying sand is then injected into the coal seam, creating gas flow channels to facilitate methane generation. The main pipe 1 is then sealed. After the microorganisms have fully interacted with the dispersed organic matter in the coal reservoir, shale, and tight rock, the regulating mechanism... 6. Close the injection hole 11 and open the extraction hole 12. At this time, the wastewater produced by the anaerobic fermentation of microorganisms flows into the gas-liquid separation mechanism 4 through the extraction hole 12. Then, the wastewater is preferentially extracted by the external extraction equipment. During the extraction process, the coal powder particles are filtered by the filter plate 42 and the discharge mechanism 44 to prevent the extraction pipe 3 from being blocked. After the wastewater is extracted, the methane produced by the microbial fermentation is extracted by the extraction mechanism. Through the gas-liquid separation mechanism and the discharge mechanism, the purity of the extracted methane is improved and its extraction speed is accelerated.

[0040] In this embodiment, as Figure 2 The main pipe 1 is provided with a plurality of injection holes 11 and extraction holes 12;

[0041] The injection hole 11 is connected to the injection pipe 2, and the extraction hole 12 is connected to the extraction pipe 3.

[0042] In this embodiment, as Figure 1 , 2 The adjustment mechanism 6 includes an adjustment seat 61 and an adjustment plate 62. The adjustment seat 61 is rotatably disposed at the input end of the main pipe 1, and the adjustment plate 62 is arc-shaped and fixedly disposed on the adjustment seat 61.

[0043] The regulating plate 62 is provided with a plurality of through holes 63 and through holes 64. The through holes 63 are the same size as the injection hole 11, and the through holes 64 are the same size as the extraction hole 12. The through holes 63 and through holes 64 are set at different positions.

[0044] Furthermore, the adjusting plate 62 is rotatably and sealingly arranged along the inner wall of the main pipe 1.

[0045] In addition, the power for the adjustment seat 61 to rotate along the main pipe 1 comes from an external drive mechanism, such as a hydraulic mechanism or a gear mechanism.

[0046] Specifically, the injection and extraction processes are separated by the adjustment mechanism 6, and the through hole 1 63 and through hole 2 64 are set at different positions so that they do not affect each other. That is, the injection hole 11 and the extraction hole 12 can only work independently, which effectively improves the convenience of bio-fracturing fluid injection and methane extraction.

[0047] In this embodiment, as Figure 3 The gas-liquid separation mechanism 4 includes a storage tank 41, a filter plate 42, and a level gauge 43. The storage tank 41 is fixedly installed on the main pipe 1 and is connected to the extraction pipe 3. The filter plate 42 is inclinedly fixedly installed in the storage tank 41, and the level gauge 43 is fixedly installed on the storage tank 41.

[0048] During implementation, the borehole is drilled at an angle, and the wastewater produced by the anaerobic fermentation of microorganisms can flow into the storage tank 41 through the extraction hole 12. Then, the wastewater is extracted according to the display of the liquid level gauge 43, so that the methane in the coal seam will not be affected during the process of removing the wastewater.

[0049] In this embodiment, as Figure 4 The liquid storage tank 41 is also provided with a discharge mechanism 44 on its side;

[0050] The discharge mechanism 44 includes a discharge seat 441 and a discharge plate 442. The discharge seat 441 is fixedly disposed on the side of the liquid storage tank 41. A discharge cavity 443 is opened in the discharge seat 441. The discharge plate 442 is rotatably disposed in the discharge cavity 443. A plurality of discharge slots 445 are spaced apart on the discharge plate 442.

[0051] The discharge chamber 443 has two discharge holes 444 on its upper and lower sides. The upper discharge hole 444 is connected to the output end of the filter plate 42, and the lower discharge hole 444 is connected to the outside of the discharge chamber 443.

[0052] In addition, the discharge plate 442 is externally connected to a drive motor, which rotates at intervals, that is, it rotates the distance of one discharge trough 445 each time.

[0053] During implementation, coal dust particles are blocked by the filter plate 42 and then enter the discharge tank 445 through the upper discharge hole 444 under the action of gravity. Subsequently, the discharge plate 442 rotates, conveying the coal dust particles to the bottom discharge hole 444 for discharge. During this process, the discharge plate 442 rotates at intervals, and the sealing of the liquid storage tank 41 is not affected. Only coal dust and a small amount of wastewater are discharged.

[0054] In this embodiment, as Figure 5 The sealing mechanism 5 includes a sealing seat 51, a sealing gasket 52, and an airbag 53. The sealing seat 51 is fixedly mounted on the main pipe 1, the sealing gasket 52 is fixedly mounted on the sealing seat 51 and extends to the output end of the main pipe 1, and an airbag 53 is provided between the sealing gasket 52 and the sealing seat 51.

[0055] During implementation, gas is injected into the airbag 53, causing the airbag 53 to inflate and push the sealing gasket 52 toward the borehole wall and the interior of the borehole, thereby sealing the borehole and creating anaerobic and non-anaerobic conditions for microbial fermentation, effectively increasing the rate of anaerobic fermentation of microorganisms.

[0056] A method for producing methane through in-situ microbial anaerobic fermentation under coal reservoir conditions includes the following steps:

[0057] S1. Drill an inclined hole using a drilling rig, insert the main pipe 1 into the hole and fix it, and then seal the hole using the sealing mechanism 5;

[0058] S2. Use the adjustment mechanism 6 to block the extraction hole 12, open the injection hole 11, then turn on the pressurization pump to inject liquid CO2 into the coal seam as a pre-fracturing fluid to create fractures, and then use bio-fracturing fluid to carry sand for fracturing, and then seal the main pipe 1.

[0059] S3. After the microorganisms have fully interacted with the dispersed organic matter in the coal reservoir, shale and tight rock, the injection hole 11 is blocked by the regulating mechanism 6 and the extraction hole 12 is opened, so that the wastewater generated by the anaerobic reaction of the microorganisms flows into the storage tank 41 through the extraction hole 12.

[0060] S4. The coal slag in the wastewater is filtered by the filter plate 42, and the coal slag enters the discharge mechanism 44 under the action of gravity, and the coal slag is discharged by the discharge mechanism 44.

[0061] S5. Based on the display of the level gauge 43 in the storage tank 41, the wastewater in the storage tank 41 is pumped out;

[0062] S6. After all the wastewater has been removed, use an external extraction device to extract and collect the CH4 generated by the anaerobic reaction of microorganisms.

[0063] In this embodiment, the anaerobic reaction equation in step S3 is:

[0064] CH3COOH==>CH4+CO2;

[0065] CO2 + 4H2 ==> CH4 + 2H2O.

[0066] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for in-situ microbial anaerobic fermentation of methane production under coal reservoir conditions, characterized in that: It includes a main pipe (1), an injection pipe (2) and an extraction pipe (3), wherein the injection pipe (2) and the extraction pipe (3) are fixedly installed inside the main pipe (1), the injection pipe (2) is connected to an external bio-fracturing fluid tank through a pressurizing pump, and the extraction pipe (3) is connected to an external extraction mechanism. The gas-liquid separation mechanism (4) is provided at the input end of the extraction pipe (3); The main pipe (1) is fixedly provided with a blocking mechanism (5) at its input end, and the main pipe (1) is also provided with an adjustment mechanism (6); The main pipe (1) is provided with multiple injection holes (11) and extraction holes (12); The injection hole (11) is connected to the injection pipe (2), and the extraction hole (12) is connected to the extraction pipe (3); The adjustment mechanism (6) includes an adjustment seat (61) and an adjustment plate (62), wherein the adjustment seat (61) is rotatably disposed at the input end of the main pipe (1), and the adjustment plate (62) is arc-shaped and fixedly disposed on the adjustment seat (61); The regulating plate (62) is provided with a plurality of through holes one (63) and through holes two (64), wherein the through hole one (63) is the same size as the injection hole (11), the through hole two (64) is the same size as the extraction hole (12), and the through holes one (63) and through holes two (64) are set at different positions; Furthermore, the adjusting plate (62) is rotatably and sealingly arranged along the inner wall of the main pipe (1); The gas-liquid separation mechanism (4) includes a storage tank (41), a filter plate (42), and a level gauge (43). The storage tank (41) is fixedly installed on the main pipe (1) and is connected to the extraction pipe (3). The filter plate (42) is fixedly installed at an inclination in the storage tank (41), and the level gauge (43) is fixedly installed on the storage tank (41).

2. The in-situ microbial anaerobic fermentation methane production device under coal reservoir conditions according to claim 1, characterized in that: The side of the liquid storage tank (41) is also provided with a discharge mechanism (44); The discharge mechanism (44) includes a discharge seat (441) and a discharge plate (442). The discharge seat (441) is fixedly disposed on the side of the liquid storage tank (41). A discharge cavity (443) is opened in the discharge seat (441). The discharge plate (442) is rotatably disposed in the discharge cavity (443). A plurality of discharge slots (445) are spaced apart on the discharge plate (442). The discharge chamber (443) has two discharge holes (444) on its upper and lower sides. The upper discharge hole (444) is connected to the output end of the filter plate (42), and the lower discharge hole (444) is connected to the outside of the discharge chamber (443).

3. The in-situ microbial anaerobic fermentation methane production device under coal reservoir conditions according to claim 2, characterized in that: The sealing mechanism (5) includes a sealing seat (51), a sealing gasket (52), and an airbag (53). The sealing seat (51) is fixedly mounted on the main pipe (1), the sealing gasket (52) is fixedly mounted on the sealing seat (51) and extends to the output end of the main pipe (1), and an airbag (53) is provided between the sealing gasket (52) and the sealing seat (51).

4. A method for producing methane through in-situ microbial anaerobic fermentation under coal reservoir conditions, comprising using a methane production apparatus for in-situ microbial anaerobic fermentation under coal reservoir conditions as described in any one of claims 2-3, characterized in that: Includes the following steps: Step S1. Drill an inclined hole using a drilling rig, insert the main pipe (1) into the hole and fix it, and then seal the hole using a sealing mechanism (5); Step S2. Use the adjustment mechanism (6) to block the extraction hole (12), open the injection hole (11), then turn on the pressurization pump, inject liquid CO2 into the coal seam as a pre-fracturing fluid to create fractures, and then use bio-fracturing fluid to carry sand for fracturing, and then seal the main pipe (1). Step S3. After the microorganisms have fully interacted with the dispersed organic matter in the coal reservoir, shale and tight rock, the injection hole (11) is blocked by the regulating mechanism (6), and the extraction hole (12) is opened so that the wastewater generated by the anaerobic reaction of the microorganisms flows into the storage tank (41) through the extraction hole (12); Step S4. Use the filter plate (42) to filter the coal slag in the wastewater. The coal slag enters the discharge mechanism (44) under the action of gravity and is discharged using the discharge mechanism (44). Step S5. Based on the display of the level gauge (43) in the storage tank (41), the wastewater in the storage tank (41) is pumped out; Step S6. After all the wastewater has been removed, use an external extraction device to extract and collect the CH4 generated by the anaerobic reaction of the microorganisms.

5. The method for producing methane by microbial anaerobic fermentation under in-situ conditions in a coal reservoir according to claim 4, characterized in that: The anaerobic reaction equation in step S3 is as follows: CH3COOH→CH4+CO2; CO2 + 4H2 → CH4 + 2H2O.

Images