Coal bed gas excitation elutriation stimulation process and equipment

Abstract

The application discloses a coal bed gas excitation elutriation yield increasing process and equipment, relates to the technical field of coal bed gas exploitation, and the coal bed gas excitation elutriation yield increasing process comprises two process modes of well repair excitation elutriation yield increasing process and production excitation elutriation yield increasing process, and the two process modes both realize coal bed gas well yield increasing through three core working procedures of reservoir fracturing, reservoir powder removal and wellbore powder removal, so that a large number of irregular macroscopic cracks are generated on the coal reservoir, and the permeability of the coal reservoir is further improved; after a large number of cracks are generated in the coal reservoir, a large amount of coal powder, coal slime and the like are generated, high-pressure gas generated by a high-pressure gas source continues to impact the coal reservoir, and energy is stored in the coal reservoir to form potential energy; after enough potential energy is accumulated, the high-pressure gas pipe is quickly removed, so that the potential energy is quickly released, and the coal powder, coal slime and the like in the cracks are wrapped and entrained into the wellbore, so that reservoir plugging removal is realized.

Description

Technical Field

[0001] This invention relates to the field of coalbed methane extraction technology, specifically to a coalbed methane induced washing and production enhancement process and equipment. Background Technology

[0002] Developing and utilizing coalbed methane resources can not only significantly increase the supply of efficient and clean energy and reduce methane emissions from coal mines to effectively mitigate the greenhouse effect, but also has the potential to curb mine gas disasters and improve safe production conditions in coal mines. This new type of clean energy has considerable direct economic benefits, significant potential economic benefits, and broad prospects.

[0003] In existing technologies, the common method for coalbed methane well extraction both domestically and internationally is drainage and depressurization extraction. As coalbed methane wells are extracted, during the water and gas production process, raw coal dust from the coal reservoir, coal dust generated by fracturing, and drilling construction pollutants will flow into the wellbore along with the water (gas), causing blockage of the near-wellbore reservoir channels, resulting in a significant reduction in coal seam permeability, which in turn affects gas production and leads to a significant decrease in production.

[0004] Therefore, this invention proposes a coalbed methane induced washing and production enhancement process and equipment. Summary of the Invention

[0005] The purpose of this invention is to provide a coalbed methane induced washing and production enhancement process and equipment to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a coalbed methane induction washing and production enhancement process, comprising two process modes: a well workover induction washing and production enhancement process and a production induction washing and production enhancement process. Both process modes achieve coalbed methane well production enhancement through three core processes: reservoir fracturing, reservoir dust removal, and wellbore dust removal. The specific steps are as follows: S1 reservoir fracturing: High-pressure gas source is used to apply pulsed gas pressure to the coal reservoir, causing the coal and rock to undergo periodic volumetric strain of expansion-contraction-expansion. Through fatigue fracturing, a large number of irregular macroscopic fractures are formed in the coal reservoir, thereby improving the permeability of the coal reservoir. The equipment containing the high-pressure gas source has a detachable atomizing and production-enhancing device installed on the outside of the gas source outlet. S2 Reservoir Powder Removal: High-pressure gas is injected into the coal reservoir using a high-pressure gas source, making the gas pressure greater than the reservoir pressure. The high-pressure gas enters the numerous irregular macroscopic fractures mentioned in S1. The gas stores energy in the reservoir to form potential energy. After accumulating sufficient potential energy, the potential energy is rapidly released and carries coal powder and coal slurry from the coal fractures into the wellbore, thereby achieving reservoir unblocking. S3 Wellbore Dust Removal: Through the Venturi effect of the jet pump, water, coal dust, coal slurry and a small amount of fracturing sand in the wellbore are sucked into the tubing. High-speed water flow carries them along the tubing to the surface, where solid-liquid-gas separation is completed by the water-gas separator. Preferably, the well repair induction flushing and production enhancement process is applied to the conventional pump inspection operation stage of coalbed methane wells. It is a single flushing and unblocking operation. The specific operation is as follows: during the pump inspection operation, the high-pressure gas source and well washing equipment are connected to the coalbed methane wellhead, and the reservoir fracturing, reservoir powder removal, and wellbore powder removal processes are executed in sequence. After washing out the reservoir coal powder in the near-wellbore area, the well repair operation is completed and the coalbed methane well production is restored.

[0007] Preferably, the production-incentivized washing and production-enhancing process is applied to the normal production stage of coalbed methane wells and is a long-term continuous washing operation. The specific operation is as follows: the washing equipment is fixed at the wellhead of the coalbed methane well, and pulse gas pressure is periodically applied to the coal reservoir and high-pressure gas is injected through an automated control system. The reservoir fracturing and reservoir powder removal processes are cyclically executed, and wellbore powder removal is continuously carried out during the production process to achieve long-term repeated action on the coal reservoir.

[0008] Preferably, a coalbed methane excitation washing and production enhancement device includes a high-pressure gas pipe, an atomizing production enhancement device installed on the high-pressure gas pipe, the upper end of the high-pressure gas pipe being connected to a high-pressure gas source, a water tank being fixedly connected to the side wall of the high-pressure gas pipe, a water filter being fixedly connected to one side of the water tank, the water filter being connected to a water pump, a flow pipe penetrating and fixedly connected to the upper side wall of the high-pressure gas pipe, a sensing terminal being fixedly connected to one end of the flow pipe extending into the high-pressure gas pipe, and a flow meter being fixedly connected to one end of the flow pipe extending out of the high-pressure gas pipe.

[0009] Preferably, the atomization production enhancement device includes a water passage chamber, which is located on the side wall of the high-pressure air pipe. An upper air pipe is fixedly connected to the upper end of the water passage chamber. The upper air pipe extends through the high-pressure air pipe and is inclined upwards, with the upward-inclined end of the upper air pipe being horizontal. Multiple lower air pipes are fixedly connected to the lower end of the water passage chamber. The lower air pipes extend through the high-pressure air pipe and are inclined downwards, with the downward-inclined end of the lower air pipe being vertical. An atomizing plate is fixedly connected inside the port of the lower air pipe. Atomizing holes are densely arranged inside the atomizing plate. Multiple water passage holes are evenly spaced on the side wall between the water passage chamber and the water tank.

[0010] Preferably, a support platform is fixedly connected to the water tank, a motor is fixedly installed on the support platform, a gear is fixedly connected to the output shaft of the motor, an adjusting plate extends through and is slidably connected to the water tank, a slot is opened in the adjusting plate, a rack is fixedly connected to one side of the slot, the rack and the gear are meshed, a blocking strip is fixedly connected to the back side of the adjusting plate, and the blocking strip is in contact with the inner side wall of the water tank where the water passage hole is located.

[0011] Preferably, a threaded ring is embedded and fixedly connected to the bottom of the outer wall of the high-pressure air pipe, and a nut is fitted at the bottom of the high-pressure air pipe. The nut and the threaded ring are threadedly connected. The nut is hollow inside, and a control tube is fixedly connected to the edge of the hollow part of the nut.

[0012] Preferably, an annular groove is provided on the inner side of the control tube, and multiple limiting rods are fixedly connected at equal intervals in the annular groove. A ring-shaped limiting block extends through and is slidably connected to the limiting rods. An acceleration tube is fixedly connected to the limiting block. The outer side of the acceleration tube is annular, and the inner side is composed of an inverted cone shape at the top and a cylindrical shape at the bottom, which can increase the speed at which the mixture of atomized water and high-pressure gas rushes out of the high-pressure gas tube.

[0013] Preferably, a connecting ring extends through and is slidably connected to the limiting rod, a connecting plate is fixedly connected to the connecting ring, and a vortex fan is rotatably connected to the bottom center of the connecting plate.

[0014] Preferably, an extension ring extends through and is slidably connected to the limiting rod, and the upper end of the connecting ring is fixedly connected to the extension ring.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention utilizes an atomization-enhanced production device to atomize water and combine it with high-pressure gas for impact. Through gas-water synergy, more and larger fractures can be formed, improving the fracturing effect and removing more coal dust that accompanies the formation of fractures. The high-speed flushing of the atomized water and high-pressure gas mixture (i.e., water vapor) can clean the fracture walls and fracturing sand pores, restoring the water and gas permeability of the fracturing sand and preventing the fracturing sand pores from being filled with coal dust, thus further promoting the coalbed methane stimulation washing and production enhancement effect. 2. This invention involves connecting a high-pressure gas pipe to a coal reservoir and a high-pressure gas source. The high-pressure gas source emits pulsed gas pressure, which impacts the coal reservoir through the high-pressure gas pipe. The coal and rock in the reservoir undergo periodic volume changes of expansion-contraction-expansion, resulting in stress fatigue and ultimately fatigue fracture, forming numerous irregular macroscopic cracks. This increases the permeability of the coal reservoir. After numerous cracks are formed, a large amount of coal dust and coal slurry are generated. High-pressure gas is then used to impact the coal reservoir, storing potential energy within it. Once sufficient potential energy is accumulated, the high-pressure gas pipe is quickly removed, rapidly releasing the potential energy and carrying the coal dust and coal slurry into the wellbore, thus unblocking the reservoir. 3. In this invention, when high-pressure gas enters the high-pressure gas pipe through a high-pressure gas source, the high-pressure gas in the high-pressure gas pipe contacts the upper gas pipe, and part of the high-pressure gas enters the water passage chamber through the upper gas pipe and then rushes out from the lower gas pipe below the water passage chamber. The water pump is placed in a clean water storage tank. The water pump injects the clean water in the clean water storage tank into the water filter through the water pipe and then into the water tank through the water filter. The clean water in the water tank continuously flows into the water passage chamber through the water passage hole. When the high-pressure gas enters the water passage chamber and flows out from the lower gas pipe, it will carry the clean water out. When the clean water passes through the atomizing plate on the lower gas pipe, it is atomized by the atomizing hole on the atomizing plate and flows into the high-pressure gas pipe. It flows with the high-pressure gas in the high-pressure gas pipe, thereby achieving the effect of gas-water synergy. 4. The present invention uses a horizontal design at the upward-sloping end of the upper air pipe, which allows the opening of the upper air pipe to face the flow direction of the high-pressure gas in the high-pressure air pipe, enabling more high-pressure gas to flow into the upper air pipe, thereby producing a better clean water atomization effect. 5. The present invention, by designing the lower air pipe with a vertical end that is inclined downwards, enables the flow direction of the high-pressure gas in the lower air pipe and the high-pressure air pipe to be parallel. After the clean water flows out of the atomizing hole and is atomized, it is directly carried away by the high-pressure airflow in the high-pressure air pipe. Furthermore, the high-pressure gas in the high-pressure air pipe will not enter the lower air pipe and will not cause convection with the high-pressure gas in the lower air pipe, thereby further promoting the atomization effect of the clean water and thus promoting the gas-water synergistic effect. 6. This invention uses a flow meter to receive real-time changes in the flow rate of high-pressure gas in a high-pressure gas pipe via a sensing terminal. The change in high-pressure gas flow rate depends on the degree of blockage in the coal reservoir; that is, the greater the blockage in the coal reservoir, the lower the flow rate of high-pressure gas. The flow meter is connected to a controller and a motor. Based on the changes in high-pressure gas flow rate received by the flow meter, the motor is controlled to operate in real time. The motor drives the gear to rotate through the output shaft. The gear meshes with the rack and the adjustment plate fixedly connected to the rack, which moves up and down. The blocking strip fixedly connected to the adjustment plate moves up and down, thereby changing the number of water passages blocked, thus changing the amount of clean water entering the water passage cavity, and consequently changing the content of atomized water in the high-pressure gas flow in the high-pressure gas pipe. In other words, through the coordinated operation of the flow meter and the motor, the gas-water coordination degree can be adjusted in real time according to the degree of blockage in the coal reservoir. For example, the more severe the blockage in the coal reservoir, the higher the proportion of atomized water in the high-pressure gas. 7. The present invention, through the design of the atomized water and high-pressure gas mixture, i.e. water vapor, passing through the high-pressure gas pipe, will pass through the acceleration pipe. The outer side of the acceleration pipe is annular, and the inner side is composed of an inverted cone at the top and a cylinder at the bottom. This design can narrow the outlet of the water vapor when it passes through the acceleration pipe, resulting in a larger flow velocity and a greater impact force of the water vapor, thereby producing a better impact effect on the coal reservoir. 8. The present invention allows water vapor to pass through a vortex fan at the outlet of the high-pressure gas pipe. The vortex fan rotates due to the impact of the water vapor, thereby promoting a more uniform mixing of the high-pressure gas and atomized water in the water vapor, so as to produce a more significant impact on the coal reservoir. 9. The design of the threaded ring and nut makes it easy to disassemble the vortex fan and acceleration tube related structures directly from the high-pressure gas pipe. The design of the limiting rod, limiting block and connecting ring makes it easy to disassemble the vortex fan and acceleration tube related structures from the control pipe. Depending on the actual situation, one or two of the structures can be used, which makes it more flexible and practical. Attached Figure Description

[0016] Figure 1 This is a flowchart of the coalbed methane induced washing and production enhancement process of the present invention; Figure 2 This is an overall structural view of the coalbed methane stimulation washing and production enhancement equipment of the present invention; Figure 3 This is a cross-sectional view of the coalbed methane stimulation washing and production enhancement equipment of the present invention; Figure 4 This is a top view of the coalbed methane stimulation washing and production enhancement equipment of the present invention; Figure 5 This is a bottom view of the coalbed methane stimulation washing and production enhancement equipment of the present invention; Figure 6 This is an assembly view of the threaded ring nut of the present invention; Figure 7 This is a side sectional view of the nut of the present invention; Figure 8 This is a meshing view of the gear and rack of the present invention; Figure 9 This is a partial cross-sectional view of the coalbed methane stimulation washing and production enhancement equipment of the present invention; Figure 10 This is a cross-sectional view of the nut of the coalbed methane excitation washing and production enhancement device of the present invention.

[0017] In the picture: 1. High-pressure air pipe; 11. Water tank; 12. Water filter; 13. Flow pipe; 14. Sensor terminal; 15. Flow meter; 2. Water passage chamber; 21. Upper air pipe; 22. Lower air pipe; 23. Atomizing plate; 24. Atomizing hole; 25. Water passage hole; 3. Motor; 31. Gear; 32. Adjusting plate; 33. Blocking strip; 34. Rack; 35. Support platform; 4. Threaded ring; 41. Nut; 42. Control pipe; 43. Annular groove; 44. Limiting rod; 45. Limiting block; 46. Accelerator pipe; 5. Connecting ring; 51. Connecting plate; 52. Vortex fan; 6. Extension ring. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1 to 10 The present invention provides a technical solution: A coalbed methane-inducing flushing and production enhancement process includes two process modes: a well workover-inducing flushing and production enhancement process and a production-inducing flushing and production enhancement process. Both process modes achieve coalbed methane well production enhancement through three core processes: reservoir fracturing, reservoir dust removal, and wellbore dust removal. The specific steps are as follows: S1 reservoir fracturing: High-pressure gas source is used to apply pulsed gas pressure to the coal reservoir, causing the coal and rock to undergo periodic volumetric strain of expansion-contraction-expansion. Through fatigue fracturing, a large number of irregular macroscopic fractures are formed in the coal reservoir, thereby improving the permeability of the coal reservoir. The equipment containing the high-pressure gas source has a detachable atomizing and production-enhancing device installed on the outside of the gas source outlet. S2 Reservoir Powder Removal: High-pressure gas is injected into the coal reservoir using a high-pressure gas source, making the gas pressure greater than the reservoir pressure. The high-pressure gas enters the numerous irregular macroscopic fractures mentioned in S1. The gas stores energy in the reservoir to form potential energy. After accumulating sufficient potential energy, the potential energy is rapidly released and carries coal powder and coal slurry from the coal fractures into the wellbore, thereby achieving reservoir unblocking. S3 Wellbore Dust Removal: Through the Venturi effect of the jet pump, water, coal dust, coal slurry and a small amount of fracturing sand in the wellbore are sucked into the tubing. High-speed water flow carries them along the tubing to the surface, where solid-liquid-gas separation is completed by the water-gas separator. The well repair-incentivized flushing and production enhancement process is applied to the conventional pump inspection stage of coalbed methane wells. It is a single flushing and unblocking operation. The specific operation is as follows: during the pump inspection operation, the high-pressure gas source and well washing equipment are connected to the coalbed methane wellhead. The reservoir fracturing, reservoir powder removal, and wellbore powder removal processes are executed in sequence. After the reservoir coal powder in the near-wellbore area is washed out, the well repair operation is completed and the coalbed methane well production is restored. The production-incentivized washing and production-enhancing process is applied to the normal production stage of coalbed methane wells. It is a long-term continuous washing operation. The specific operation is as follows: the washing equipment is fixed at the wellhead of the coalbed methane well, and pulse gas pressure is periodically applied to the coal reservoir and high-pressure gas is injected through an automated control system. The reservoir fracturing and reservoir powder removal processes are cyclically executed. At the same time, wellbore powder removal is continuously carried out during the production process to achieve long-term repeated action on the coal reservoir.

[0020] The atomization enhancement device can atomize water and combine it with high-pressure gas for impact. Through gas-water synergy, it can form more and larger fractures, improve the fracturing effect, and remove more coal dust that accompanies the formation of fractures. The high-speed flushing of the atomized water and high-pressure gas mixture (i.e., water vapor) can clean the fracture walls and fracturing sand pores, restore the water and air permeability of the fracturing sand, and prevent the fracturing sand pores from being filled with coal dust, which would reduce the seepage capacity. This further promotes the coalbed methane stimulation washing and production enhancement effect.

[0021] A coalbed methane excitation and washing production enhancement device includes a high-pressure gas pipe 1, an atomization production enhancement device installed on the high-pressure gas pipe 1, an upper end of the high-pressure gas pipe 1 connected to a high-pressure gas source, a water tank 11 fixedly connected to the side wall of the high-pressure gas pipe 1, a water filter 12 fixedly connected to one side of the water tank 11, the water filter 12 being connected to a water pump, a flow pipe 13 penetrating and fixedly connected to the upper side wall of the high-pressure gas pipe 1, a sensing terminal 14 fixedly connected to one end of the flow pipe 13 extending into the high-pressure gas pipe 1, and a flow meter 15 fixedly connected to one end of the flow pipe 13 extending out of the high-pressure gas pipe 1.

[0022] The atomization production enhancement device includes a water passage chamber 2, which is located on the side wall of the high-pressure air pipe 1. An upper air pipe 21 is fixedly connected to the upper end of the water passage chamber 2. The upper air pipe 21 extends through the high-pressure air pipe 1 and is inclined upward, with the upward-inclined end of the upper air pipe 21 being horizontal. Multiple lower air pipes 22 are fixedly connected to the lower end of the water passage chamber 2. The lower air pipes 22 extend through the high-pressure air pipe 1 and are inclined downward, with the downward-inclined end of the lower air pipe 22 being vertical. An atomizing plate 23 is fixedly connected inside the port of the lower air pipe 22. Atomizing holes 24 are densely arranged inside the atomizing plate 23. Multiple water passage holes 25 are equally spaced on the side wall between the water passage chamber 2 and the water tank 11.

[0023] During operation, when high-pressure gas enters high-pressure gas pipe 1 through high-pressure gas source, the high-pressure gas in high-pressure gas pipe 1 comes into contact with upper gas pipe 21, and part of the high-pressure gas enters water passage chamber 2 through upper gas pipe 21 and then rushes out from lower gas pipe 22 below water passage chamber 2. The water pump is placed in clean water storage tank. The water pump injects clean water in clean water storage tank into water filter 12 through water pipe and into water tank 11 through water filter 12. The clean water in water tank 11 flows into water passage chamber 2 continuously through water passage hole 25. When high-pressure gas enters water passage chamber 2 and flows out from lower gas pipe 22, it will carry clean water out. When the clean water passes through atomizing plate 23 on lower gas pipe 22, it is atomized by atomizing hole 24 on atomizing plate 23 and flows into high-pressure gas pipe 1. It flows with high-pressure gas in high-pressure gas pipe 1, thereby achieving the effect of gas-water synergy. The upward-sloping end of the upper air pipe 21 is designed to be horizontal, which allows the opening of the upper air pipe 21 to face the flow direction of the high-pressure gas in the high-pressure air pipe 1, allowing more high-pressure gas to flow into the upper air pipe 21, thereby producing a better clean water atomization effect. The downward-sloping end of the lower air pipe 22 is designed to be vertical, which allows the flow direction of the high-pressure gas in the lower air pipe 22 and the high-pressure air pipe 1 to be parallel. After the clean water flows out of the atomizing hole 24 and is atomized, it is directly carried away by the high-pressure airflow in the high-pressure air pipe 1. The high-pressure gas in the high-pressure air pipe 1 will not enter the lower air pipe 22 and create convection with the high-pressure gas in the lower air pipe 22, thereby further promoting the atomization effect of the clean water and promoting the gas-water synergistic effect.

[0024] As an embodiment of the present invention, as shown in the figure, a support platform 35 is fixedly connected to the water tank 11, a motor 3 is fixedly installed on the support platform 35, a gear 31 is fixedly connected to the output shaft of the motor 3, an adjusting plate 32 extends through and is slidably connected to the water tank 11, a slot is opened in the adjusting plate 32, a rack 34 is fixedly connected to one side of the slot, the rack 34 and the gear 31 are meshed, a blocking strip 33 is fixedly connected to the back side of the adjusting plate 32, and the blocking strip 33 is in contact with the inner wall of the water tank 11 where the water passage hole 25 is located.

[0025] During operation, the flow meter 15 receives real-time changes in the high-pressure gas flow rate in the high-pressure gas pipe 1 through the sensor terminal 14. The changes in the high-pressure gas flow rate depend on the degree of blockage in the coal reservoir; that is, the greater the degree of blockage in the coal reservoir, the lower the high-pressure gas flow rate. The flow meter 15 is connected to the controller and the motor 3. Based on the changes in the high-pressure gas flow rate received by the flow meter 15, the motor 3 is controlled to work in real time. The motor 3 drives the gear 31 to rotate through the output shaft. The rack 34 and the adjusting plate 32 fixedly connected to the rack 34 move up and down. The blocking strip 33 fixedly connected to the adjusting plate 32 moves up and down, thereby changing the number of water passage holes 25 blocked, thereby changing the amount of clean water entering the water passage chamber 2, and thus changing the content of atomized water in the high-pressure gas flow in the high-pressure gas pipe 1. That is, through the coordinated work of the flow meter 15 and the motor 3, the gas-water coordination degree can be adjusted in real time according to the degree of blockage in the coal reservoir. For example, the more severe the blockage in the coal reservoir, the higher the proportion of atomized water in the high-pressure gas.

[0026] As an embodiment of the present invention, as shown in the figure, a threaded ring 4 is embedded and fixedly connected to the bottom of the outer side wall of the high-pressure air pipe 1, and a nut 41 is fitted at the bottom of the high-pressure air pipe 1. The nut 41 and the threaded ring 4 are threadedly connected. The nut 41 is hollow inside, and a control tube 42 is fixedly connected to the edge of the hollow part of the nut 41.

[0027] During operation, when the mixture of atomized water and high-pressure gas, i.e. water vapor, rushes out of the high-pressure gas pipe 1, it will pass through the acceleration pipe 46. The outer side of the acceleration pipe 46 is annular, and the inner side is composed of an inverted cone at the top and a cylinder at the bottom. This design narrows the outlet of the water vapor as it passes through the acceleration pipe 46, resulting in a larger flow velocity and a greater impact force of the water vapor, thus producing a better impact effect on the coal reservoir.

[0028] As an embodiment of the present invention, as shown in the figure, an annular groove 43 is provided on the inner side of the control tube 42. Multiple limiting rods 44 are fixedly connected at equal intervals in the annular groove 43. An annular limiting block 45 extends through and is slidably connected to the limiting rods 44. An acceleration tube 46 is fixedly connected to the limiting block 45. The outer side of the acceleration tube 46 is annular, and the inner side is composed of an inverted cone shape at the top and a cylindrical shape at the bottom, which can increase the speed at which the mixture of atomized water and high-pressure gas rushes out of the high-pressure gas tube 1.

[0029] During operation, when the water vapor passes through the outlet of the high-pressure gas pipe 1, it first passes through the vortex fan 52. The vortex fan 52 rotates due to the impact of the water vapor, which can promote a more uniform mixing of the high-pressure gas and atomized water in the water vapor, so as to produce a further impact effect on the coal reservoir.

[0030] As an embodiment of the present invention, as shown in the figure, a connecting ring 5 extends through and is slidably connected to the limiting rod 44, a connecting plate 51 is fixedly connected to the connecting ring 5, and a vortex fan 52 is rotatably connected to the bottom center of the connecting plate 51; an extension ring 6 extends through and is slidably connected to the limiting rod 44, and the upper end of the connecting ring 5 is fixedly connected to the extension ring 6.

[0031] During operation, the design of the threaded ring 4 and the nut 41 makes it easy to directly remove the vortex fan 52 and the acceleration tube 46 from the high-pressure air pipe 1. The design of the limiting rod 44, the limiting block 45, and the connecting ring 5 makes it easy to remove the vortex fan 52 and the acceleration tube 46 from the control pipe 42. Depending on the actual situation, one or two of the structures can be used, which makes the use more flexible and practical. The design of the limiting rod 44 and the extension ring 6 ensures that when the vortex fan 52 and the acceleration tube 46 are used simultaneously, there will be a certain distance between them, i.e. the length of the extension ring 6. This allows water vapor to have a transition period after passing through the vortex fan 52 before entering the acceleration tube 46 for acceleration, resulting in better performance.

[0032] Working principle: High-pressure gas pipe 1 is positioned against the coal reservoir and connected to a high-pressure gas source. The high-pressure gas source emits pulsed gas pressure, which impacts the coal reservoir through high-pressure gas pipe 1. The coal and rock in the reservoir undergo periodic volume changes of expansion-contraction-expansion, resulting in stress fatigue. Ultimately, fatigue fracture occurs under stress fatigue, forming numerous irregular macroscopic cracks. This increases the permeability of the coal reservoir. After numerous cracks are generated in the coal reservoir, a large amount of coal dust and coal slurry are produced. High-pressure gas is then generated through the high-pressure gas source to impact the coal reservoir and store potential energy within it. After accumulating sufficient potential energy, the gas pipe 1 is quickly removed, rapidly releasing the potential energy and carrying the coal dust and coal slurry from the cracks into the wellbore, thus unblocking the reservoir. In the above process, we added an atomization enhancement device. Through the atomization enhancement device, water can be atomized and then combined with high-pressure gas for impact. Through gas-water synergy, more and larger fractures can be formed, which can improve the storage fracturing effect and also bring out more coal dust that accompanies the formation of fractures. The high-speed flushing of the mixture of atomized water and high-pressure gas, i.e., water vapor, can clean the fracture wall and fracturing sand pores, restore the water and air passage capacity of the fracturing sand, and prevent the fracturing sand pores from being filled with coal dust, which would reduce the seepage capacity and further promote the coalbed methane stimulation washing enhancement effect. The atomization production enhancement device is as follows: When high-pressure gas enters the high-pressure gas pipe 1 through the high-pressure gas source, the high-pressure gas in the high-pressure gas pipe 1 comes into contact with the upper gas pipe 21, and part of the high-pressure gas enters the water passage chamber 2 through the upper gas pipe 21 and then rushes out from the lower gas pipe 22 below the water passage chamber 2. The water pump is placed in the clean water storage tank. The water pump injects the clean water in the clean water storage tank into the water passer 12 through the water passer 12 and into the water tank 11 through the water passer 12. The clean water in the water tank 11 flows into the water passage chamber 2 continuously through the water passage hole 25. When the high-pressure gas enters the water passage chamber 2 and flows out from the lower gas pipe 22, it will carry the clean water out. When the clean water passes through the atomizing plate 23 on the lower gas pipe 22, it is atomized by the atomizing hole 24 on the atomizing plate 23 and flows into the high-pressure gas pipe 1. It flows with the high-pressure gas in the high-pressure gas pipe 1, thereby achieving the effect of gas-water synergy. The upward-sloping end of the upper air pipe 21 is designed to be horizontal, which allows the opening of the upper air pipe 21 to face the flow direction of the high-pressure gas in the high-pressure air pipe 1, allowing more high-pressure gas to flow into the upper air pipe 21, thereby producing a better clean water atomization effect. The downward-sloping end of the lower air pipe 22 is designed to be vertical, which allows the flow direction of the high-pressure gas in the lower air pipe 22 and the high-pressure air pipe 1 to be parallel. After the clean water flows out of the atomizing hole 24 and is atomized, it is directly carried away by the high-pressure airflow in the high-pressure air pipe 1. The high-pressure gas in the high-pressure air pipe 1 will not enter the lower air pipe 22 and create convection with the high-pressure gas in the lower air pipe 22, thereby further promoting the atomization effect of the clean water and promoting the gas-water synergistic effect. The flow meter 15 receives the changes in the high-pressure gas flow rate in the high-pressure gas pipe 1 in real time through the sensor terminal 14. The changes in the high-pressure gas flow rate depend on the degree of blockage in the coal reservoir. That is, the greater the degree of blockage in the coal reservoir, the smaller the high-pressure gas flow rate. The flow meter 15 is connected to the controller and the motor 3. According to the changes in the high-pressure gas flow rate received by the flow meter 15, the motor 3 is controlled to work in real time. The motor 3 drives the gear 31 to rotate through the output shaft. The rack 34 and the adjusting plate 32 fixedly connected to the rack 34 move up and down. The blocking strip 33 fixedly connected to the adjusting plate 32 moves up and down, thereby changing the number of water passage holes 25 blocked, thereby changing the amount of clean water entering the water passage chamber 2, and thus changing the content of atomized water in the high-pressure gas flow in the high-pressure gas pipe 1. That is, through the coordinated work of the flow meter 15 and the motor 3, the gas-water coordination degree can be adjusted in real time according to the degree of blockage in the coal reservoir. For example, the more severe the blockage in the coal reservoir, the higher the proportion of atomized water in the high-pressure gas. When the mixture of atomized water and high-pressure gas, i.e. water vapor, rushes out of the high-pressure gas pipe 1, it will pass through the acceleration pipe 46. The outer side of the acceleration pipe 46 is annular, and the inner side is composed of an inverted cone at the top and a cylinder at the bottom. This design narrows the outlet of the water vapor as it passes through the acceleration pipe 46, resulting in a larger flow velocity and a greater impact force of the water vapor, thus producing a better impact effect on the coal reservoir. When the water vapor passes through the outlet of the high-pressure gas pipe 1, it will first pass through the vortex fan 52. The vortex fan 52 will rotate due to the impact of the water vapor, which will make the high-pressure gas and atomized water in the water vapor mix more evenly, so as to produce a further impact effect on the coal reservoir. The design of the threaded ring 4 and the nut 41 makes it easy to remove the vortex fan 52 and the acceleration tube 46 from the high-pressure air pipe 1. The design of the limiting rod 44, the limiting block 45, and the connecting ring 5 makes it easy to remove the vortex fan 52 and the acceleration tube 46 from the control pipe 42. Depending on the actual situation, one or two of the structures can be used, which makes the use more flexible and practical. The design of the limiting rod 44 and the extension ring 6 ensures that when the vortex fan 52 and the acceleration tube 46 are used simultaneously, there will be a certain distance between them, i.e. the length of the extension ring 6. This allows water vapor to have a transition period after passing through the vortex fan 52 before entering the acceleration tube 46 for acceleration, resulting in better performance.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coalbed methane induced washing and production enhancement process, characterized in that, The process includes two modes: well workover-incentivized flushing for enhanced production and production-incentivized flushing for enhanced production. Both modes achieve enhanced coalbed methane well production through three core processes: reservoir fracturing, reservoir dust removal, and wellbore dust removal. The specific steps are as follows: S1 reservoir fracturing: High-pressure gas source is used to apply pulsed gas pressure to the coal reservoir, causing the coal and rock to undergo periodic volumetric strain of expansion-contraction-expansion. Through fatigue fracturing, a large number of irregular macroscopic fractures are formed in the coal reservoir, thereby improving the permeability of the coal reservoir. The equipment containing the high-pressure gas source has a detachable atomizing and production-enhancing device installed on the outside of the gas source outlet. S2 Reservoir Powder Removal: High-pressure gas is injected into the coal reservoir using a high-pressure gas source, making the gas pressure greater than the reservoir pressure. The high-pressure gas enters the numerous irregular macroscopic fractures mentioned in S1. The gas stores energy in the reservoir to form potential energy. After accumulating sufficient potential energy, the potential energy is rapidly released and carries coal powder and coal slurry from the coal fractures into the wellbore, thereby achieving reservoir unblocking. S3 Wellbore Dust Removal: Through the Venturi effect of the jet pump, water, coal dust, coal slurry, and a small amount of fracturing sand in the wellbore are sucked into the tubing. High-speed water flow carries them along the tubing to the surface, where solid-liquid-gas separation is completed by the water-gas separator.

2. The coalbed methane stimulated washing and production enhancement process according to claim 1, characterized in that: The well repair-incentivized flushing and production enhancement process is applied to the conventional pump inspection stage of coalbed methane wells. It is a single flushing and unblocking operation. The specific operation is as follows: during the pump inspection operation, the high-pressure gas source and well washing equipment are connected to the coalbed methane wellhead. The reservoir fracturing, reservoir powder removal, and wellbore powder removal processes are executed in sequence. After the reservoir coal powder in the near-wellbore area is washed out, the well repair operation is completed and the coalbed methane well production is restored.

3. The coalbed methane stimulated washing and production enhancement process according to claim 2, characterized in that: The production-incentivized washing and production-enhancing process is applied to the normal production stage of coalbed methane wells. It is a long-term continuous washing operation. The specific operation is as follows: the washing equipment is fixed at the wellhead of the coalbed methane well, and pulse gas pressure is periodically applied to the coal reservoir and high-pressure gas is injected through an automated control system. The reservoir fracturing and reservoir powder removal processes are cyclically executed. At the same time, wellbore powder removal is continuously carried out during the production process to achieve long-term repeated action on the coal reservoir.

4. A coalbed methane induced washing and production enhancement device, applied to the coalbed methane induced washing and production enhancement process according to any one of claims 1-3, characterized in that: The device includes a high-pressure air pipe (1), on which an atomizing production enhancement device is provided. The upper end of the high-pressure air pipe (1) is connected to a high-pressure air source. A water tank (11) is fixedly connected to the side wall of the high-pressure air pipe (1). A water filter (12) is fixedly connected to one side of the water tank (11). The water filter (12) is connected to a water pump. A flow pipe (13) is fixedly connected through and fixedly connected to the upper side wall of the high-pressure air pipe (1). A sensor terminal (14) is fixedly connected to one end of the flow pipe (13) that extends into the high-pressure air pipe (1). A flow meter (15) is fixedly connected to one end of the flow pipe (13) that extends out of the high-pressure air pipe (1).

5. The coalbed methane stimulation washing and production enhancement equipment according to claim 4, characterized in that: The atomizing production enhancement device includes a water passage chamber (2), which is located on the side wall of the high-pressure air pipe (1). The upper end of the water passage chamber (2) is fixedly connected to an upper air pipe (21). The upper air pipe (21) extends through the high-pressure air pipe (1) and is inclined upward. The port of the inclined upward end of the upper air pipe (21) is horizontal. The lower end of the water passage chamber (2) is fixedly connected to multiple lower air pipes (22). The lower air pipes (22) extend through the high-pressure air pipe (1) and are inclined downward. The port of the inclined downward end of the lower air pipe (22) is vertical. An atomizing plate (23) is fixedly connected inside the port of the lower air pipe (22). Atomizing holes (24) are densely opened inside the atomizing plate (23). Multiple water passage holes (25) are opened at equal intervals on the side wall between the water passage chamber (2) and the water tank (11).

6. The coalbed methane stimulation washing and production enhancement equipment according to claim 5, characterized in that: A support platform (35) is fixedly connected to the water tank (11), and a motor (3) is fixedly installed on the support platform (35). A gear (31) is fixedly connected to the output shaft of the motor (3). An adjusting plate (32) extends through and is slidably connected inside the water tank (11). A slot is provided inside the adjusting plate (32). A rack (34) is fixedly connected to one side of the slot. The rack (34) and the gear (31) are meshed. A blocking strip (33) is fixedly connected to the back side of the adjusting plate (32). The blocking strip (33) is in contact with the inner wall of the water tank (11) where the water passage hole (25) is located.

7. The coalbed methane induced washing and production enhancement equipment according to claim 6, characterized in that: The high-pressure air pipe (1) has a threaded ring (4) embedded in the bottom of the outer wall. The bottom of the high-pressure air pipe (1) is fitted with a nut (41). The nut (41) and the threaded ring (4) are threaded together. The nut (41) is hollow inside, and a control tube (42) is fixedly connected to the edge of the hollow part of the nut (41).

8. The coalbed methane induced washing and production enhancement equipment according to claim 7, characterized in that: The control tube (42) has an annular groove (43) on its inner side. Multiple limiting rods (44) are fixedly connected at equal intervals in the annular groove (43). A ring-shaped limiting block (45) extends through and slides through the limiting rods (44). An acceleration tube (46) is fixedly connected to the limiting block (45). The outer side of the acceleration tube (46) is annular, and the inner side is composed of an inverted cone shape at the top and a cylindrical shape at the bottom, which can make the mixture of atomized water and high-pressure gas rush out of the high-pressure gas tube (1) at a certain speed.

9. The coalbed methane induced washing and production enhancement equipment according to claim 8, characterized in that: A connecting ring (5) extends through and slides on the limiting rod (44), and a connecting plate (51) is fixedly connected to the connecting ring (5). A vortex fan (52) is rotatably connected to the bottom center of the connecting plate (51).

10. A coalbed methane induced washing and production enhancement device according to claim 9, characterized in that: An extension ring (6) extends through and is slidably connected to the limiting rod (44), and the upper end of the connecting ring (5) is fixedly connected to the extension ring (6).

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