A highly efficient coal seam fracturing device

Abstract

The present invention belongs to the technical field of coalbed methane mining, and discloses a coalbed fracturing device with high efficiency, including an injection pipe, a fracturing hole and a packer, wherein the packer is provided with an upper compartment and a lower compartment respectively, and the outer surface of the packer is provided with an isolation groove, and the inner wall of the isolation groove is sealed and connected with multiple groups of upper partitions and lower partitions, and a sealing mechanism is provided in the upper compartment and the lower compartment; the sealing mechanism includes a motor, and the output shaft of the motor is equipped with a gear 1, and the opposite back surfaces of the upper partition and the lower partition are fixedly connected with sliders. The device redesigns the packer, greatly enhancing its sealing performance, and uses the straight cutting surface formed by cutting the upper partition and the lower partition to abut against it, automatically forming a seal, and then, under the pressure formed by the fracturing fluid on the upper partition and the lower partition, the upper partition and the lower partition form a more favorable abutment seal with the inner wall of the coal seam cut by them, so that the sealing performance of the packer is significantly enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of coal bed gas mining, and in particular relates to a coal bed fracturing device with high efficiency. Background Art

[0002] Coalbed methane is an unconventional natural gas mainly composed of methane. In the coal seam, it is mainly present in the adsorbed state on the surface of coal matrix particles, and in the free state in the coal pores and dissolved in the coal seam water. Due to the dense coal reservoir, the coal reservoir needs to be fractured during the coalbed methane extraction process. In the existing fracturing technology, an injection pipe equipped with a packer goes deep into the coal seam along the wellhead drilled by the drilling rig, and then the fracturing fluid is pumped into the injection pipe by a pump located on the ground. A fracturing port is opened on the outside of the injection pipe, and packers are set on both sides of the fracturing port. The packer abuts against the inner wall of the combined production well through mechanical expansion to form a seal, and then the fracturing fluid is ejected through the fracturing port to form a The invention relates to a packer which is used to seal or enlarge cracks in the coal seam which are beneficial to the migration of coalbed methane. However, in the prior art, the sealing method of the packer is not reliable enough, and the surface thereof is entirely made of sealing materials. The seal formed by the abutment with the outer coal body of the perforation of the coal seam under the action of mechanical expansion is difficult to withstand the huge water pressure of the fracturing fluid, thereby causing the following potential threats: the rubber sealing layer on the surface abuts against the outer coal body of the perforation of the coal seam, and may slide under the action of water pressure, causing the rubber layer to wear and lose its sealing function. At the same time, it may also cause damage to the packer, making it difficult to recover the equipment to the ground. Therefore, the present invention is committed to designing a new and efficient coal seam fracturing device to overcome the above problems. Summary of the invention

[0003] The purpose of the present invention is to provide a coal seam fracturing device with high efficiency to solve the problems raised in the above background technology.

[0004] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: a highly efficient coal seam fracturing device, comprising an injection pipe, wherein the outer surface of the injection pipe is provided with a plurality of groups of fracturing holes, wherein the injection pipe is internally installed with a plurality of groups of packers, wherein the interior of the packers is respectively provided with an upper compartment and a lower compartment, wherein the outer surface of the packers is provided with an isolation groove, wherein the inner wall of the isolation groove is sealed and connected with a plurality of groups of upper partitions and lower partitions, wherein the inner cavities of the upper compartment and the lower compartment are both provided with sealing mechanisms, wherein the two groups of the sealing mechanisms are respectively connected to the upper partition and the lower partition in a transmission manner;

[0005] The sealing mechanism includes a motor, and a gear 1 is installed on the output shaft of the motor. The opposite back surfaces of the upper partition and the lower partition are fixedly connected with sliders. The inner walls of the upper partition and the lower partition are movably sleeved with outer rotating rings. The inner wall of the sealer is rotatably installed with an inner rotating ring. The inner walls of the upper partition and the lower partition are rotatably installed with a rotating drum. The outer surface of the rotating drum is fixedly installed with a gear 2, and the gear 1 is meshed with the gear 2. A plurality of sets of fixing strips are also fixedly connected to the side of the outer surface of the rotating drum close to the upper partition or the lower partition, and the fixing strips are in contact with the slider.

[0006] As a preferred solution of the present invention, the upper baffle and the lower baffle are equal in shape and size and are both fan-shaped. The contact surfaces of the upper baffle and the lower baffle are sealed and abutted. The number of the upper baffle and the lower baffle is set to six groups and they are equidistantly distributed inside the sealer. The upper baffle and the lower baffle are staggered and inclined at 30°, and a plurality of groups of fixed columns are fixedly connected between the inner rotating ring and the outer rotating ring.

[0007] As a preferred solution of the present invention, a spring is movably sleeved on the outer surface of the fixing column, two ends of the spring are elastically connected to the outer rotating ring and one end of the slider respectively, and the fixing strip abuts against the other end of the slider.

[0008] As a preferred solution of the present invention, the fixing bars are arranged in six groups and are equidistantly distributed on the outer surface of the inner rotating ring in a circular pattern. The fixing bars are located in the tangent direction of the inner rotating ring, and the angle between the fixing bars and the axis of the fixing column is an obtuse angle.

[0009] As a preferred solution of the present invention, the upper partition and the lower partition are both made of high manganese alloy steel, and the outer surfaces of the upper partition and the lower partition are coated with wear-resistant and oxidation-resistant coatings.

[0010] As a preferred solution of the present invention, the upper partition or the lower partition can slide along the axis of the slider and the fixed column connected thereto. When multiple groups of the upper partitions and the lower partitions are completely and equidistantly extended to the outside of the packer, the multiple groups of the upper partitions and the lower partitions can form a group of annular sealing layers.

[0011] As a preferred solution of the present invention, the upper and lower groups of the rotating drum and the inner rotating ring are both rotatably mounted on the inner wall of the packer, and the rotating drum and the inner rotating ring abut against each other.

[0012] As a preferred solution of the present invention, a bend is provided at one end of the fixing strip, the bend coincides with a set of radial lines of the packer, and a gap is left between the bend and the inner wall of the outer rotating ring.

[0013] The beneficial effects of the present invention are as follows:

[0014] 1. This device redesigns the packer, greatly enhancing its sealing performance. By opening an isolation groove on the outer surface of the packer, it can seal and clamp multiple groups of upper and lower baffles that abut against each other. The upper and lower baffles can move synchronously outward along the radial line of the packer. The motor drives the gear 1, gear 2, rotating drum and fixed bar to rotate, driving the slider and the upper baffle to move outward along the axis of the fixed column, so that the upper and lower baffles protrude from the outer surface of the packer and abut against the inner wall of the coal seam. At the same time, the fixed bar can also drive the slider, fixed column and upper baffle. It rotates around the axis of the packer to cut the inner wall of the coal seam. As the cutting depth increases, the upper and lower baffles gradually penetrate into the cutting groove until they are in place. The upper and lower baffles are directly wedged into the cutting groove to form a seal with the packer. When the fracturing fluid is ejected from the fracturing hole, the straight cutting surface formed by the cutting of the upper and lower baffles abuts against it, automatically forming a seal. Subsequently, the pressure formed by the fracturing fluid on the upper and lower baffles causes the upper and lower baffles to form a more favorable abutment seal with the inner wall of the coal seam they cut, significantly enhancing the sealing performance of the packer.

[0015] 2. At the same time, the redesigned seal of the present invention can completely avoid the displacement and wear caused by the rubber seal. The power is provided by the rotation of the motor to drive the rotation of the fixed bar and the upper partition. The slider is used to convert the rotation torque of the fixed bar into the displacement of the upper partition along the axis of the fixed column, so that the upper and lower partitions automatically extend outward during the cutting process. When the upper and lower partitions are wedged into the inner wall of the cut coal seam, the cutting surface is straight, forming a natural and effective seal. The upper and lower partitions will not be displaced and will not wear, which effectively improves the reliability of the device.

[0016] 3. The abutment seal of the upper baffle and the lower baffle enables them to form a whole with sealing function. When the upper baffle moves toward the outside of the packer along the radial line of the packer, a gap will be generated between adjacent baffles. Therefore, lower baffles with the same number, size and shape as the upper baffles are designed to be staggered with them. In this way, the upper baffle and the lower baffle can be sealed with each other synchronously when extending outward, and they can abut against the cutting grooves formed by cutting on the inner wall of the coal seam. When the fracturing fluid generates pressure on the upper baffle and the lower baffle, not only can the upper baffle and the lower baffle be abutted more tightly, but also the upper baffle or the lower baffle can be abutted more tightly against the inner wall of the coal seam, which can significantly enhance the sealing performance of the device, and can also prevent the pressure of the fracturing fluid from being wasted, making the fracturing work of the device more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the separation of the sealing structure of the present invention;

[0018] Figure 2 It is a schematic diagram of the front appearance of the overall structure of the present invention;

[0019] Figure 3 It is a front cutaway schematic diagram of the sealing structure of the present invention;

[0020] Figure 4 For the present invention Figure 3 A magnified schematic diagram of the structure at center A;

[0021] Figure 5 It is a schematic diagram of the internal top view of the packer of the present invention;

[0022] Figure 6 For the present invention Figure 5 A magnified schematic diagram of the structure at B in the middle;

[0023] Figure 7 It is a bottom view structural schematic diagram of the sealing structure of the present invention;

[0024] Figure 8 It is a schematic diagram of the structure of the upper partition and the lower partition of the present invention.

[0025] In the figure: 1. injection pipe; 2. fracturing hole; 3. packer; 4. isolation groove; 5. upper partition; 6. lower partition; 7. slider; 8. fixed column; 9. inner swivel; 10. outer swivel; 11. spring; 12. rotating drum; 13. fixing bar; 14. motor; 15. gear 1; 16. gear 2; 17. sealing mechanism; 18. upper partition; 19. lower partition. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] like Figures 1 to 8 As shown, an embodiment of the present invention provides a coal seam fracturing device with high efficiency, including an injection pipe 1, wherein the outer surface of the injection pipe 1 is provided with a plurality of groups of fracturing holes 2, wherein a plurality of groups of packers 3 are installed inside the injection pipe 1, wherein an upper partition 18 and a lower partition 19 are respectively provided inside the packers 3, an isolation groove 4 is provided on the outer surface of the packers 3, wherein a plurality of groups of upper partitions 5 and lower partitions 6 are sealed and clamped on the inner wall of the isolation groove 4, and the inner cavities of the upper partition 18 and the lower partition 19 are both provided with sealing mechanisms 17, and the two groups of sealing mechanisms 17 are respectively connected to the upper partition 5 and the lower partition 6 in a transmission manner;

[0028] The sealing mechanism 17 includes a motor 14, the output shaft of the motor 14 is installed with a gear 15, the opposite back surfaces of the upper partition 5 and the lower partition 6 are fixedly connected with a slider 7, the inner walls of the upper partition 18 and the lower partition 19 are movably sleeved with an outer swivel 10, the inner wall of the packer 3 is rotatably installed with an inner swivel 9, the inner walls of the upper partition 18 and the lower partition 19 are rotatably installed with a rotating drum 12, the outer surface of the rotating drum 12 is fixedly installed with a gear 2 16, the gear 15 is meshed with the gear 2 16, and the outer surface of the rotating drum 12 is also fixedly connected to a side close to the upper partition 5 or the lower partition 6, and the fixing bars 13 are in contact with the slider 7;

[0029] The device redesigns the packer 3, greatly enhancing its sealing performance. By opening an isolation groove 4 on the outer surface of the packer 3, it can be sealed and clamped with multiple groups of upper baffles 5 and lower baffles 6 that abut against each other. The upper baffles 5 and the lower baffles 6 can move synchronously outward along the radial line of the packer 3. The motor 14 drives the gear 1 15, the gear 2 16, the rotating drum 12 and the fixing bar 13 to rotate, driving the slider 7 and the upper baffle 5 to move outward along the axis of the fixing column 8, so that the upper baffle 5 and the lower baffle 6 protrude from the outer surface of the packer 3 and abut against the inner wall of the coal seam. At the same time, the fixing bar 13 can also drive the slider 7 and the fixing column 8 to rotate. 8 and the upper baffle 5 rotate around the axis of the packer 3 to cut the inner wall of the coal seam. As the cutting depth increases, the upper baffle 5 and the lower baffle 6 gradually penetrate into the cutting groove until they are in place, and the upper baffle 5 and the lower baffle 6 are directly wedged into the cutting groove to form a seal with the packer 3. When the fracturing fluid is sprayed out from the fracturing hole 2, the straight cutting surface formed by the upper baffle 5 and the lower baffle 6 abuts against it, automatically forming a seal. Subsequently, the pressure formed by the fracturing fluid on the upper baffle 5 and the lower baffle 6 causes the upper baffle 5 and the lower baffle 6 to form a more favorable abutment seal with the inner wall of the coal seam they cut, thereby significantly enhancing the sealing performance of the packer 3.

[0030] At the same time, the redesigned seal 3 of the present invention can completely avoid the displacement and wear caused by the rubber seal. The power is provided by the rotation of the motor 14 to drive the fixed bar 13 and the upper partition 5 to rotate. The slider 7 is used to convert the rotation torque of the fixed bar 13 into the displacement of the upper partition 5 along the axis of the fixed column 8, so that the upper partition 5 and the lower partition 6 automatically extend outward during the cutting process. When the upper partition 5 and the lower partition 6 are wedged into the inner wall of the cut coal seam, the cutting surface is straight, forming a natural and effective seal. The upper partition 5 and the lower partition 6 will not be displaced or worn, thereby effectively improving the reliability of the device.

[0031] The upper baffle 5 and the lower baffle 6 are of equal shape and size and are both fan-shaped. The contact surfaces of the upper baffle 5 and the lower baffle 6 are sealed and abutted. The number of the upper baffle 5 and the lower baffle 6 is set to six groups and is equidistantly distributed inside the packer 3. The upper baffle 5 and the lower baffle 6 are staggered and distributed at an angle of 30°. A plurality of groups of fixing columns 8 are fixedly connected between the inner rotating ring 9 and the outer rotating ring 10.

[0032] The abutment seal of the upper baffle 5 and the lower baffle 6 enables them to form a whole with a sealing function. When the upper baffle 5 moves along the radial line of the packer 3 toward the outside of the packer 3, a gap will be generated between adjacent baffles. Therefore, the lower baffles 6 with the same number, size and shape as the upper baffles 5 are designed to be staggered with them, so that the upper baffle 5 and the lower baffle 6 can be sealed with each other synchronously when extending outward, and the cutting grooves formed by cutting on the inner wall of the coal seam are used to abut against them. When the fracturing fluid generates pressure on the upper baffle 5 and the lower baffle 6, not only can the upper baffle 5 and the lower baffle 6 be abutted more tightly, but also the upper baffle 5 or the lower baffle 6 can be abutted more tightly against the inner wall of the coal seam, which can significantly enhance the sealing performance of the device, and can also prevent the pressure of the fracturing fluid from being wasted, making the fracturing work of the device more efficient.

[0033] The outer surface of the fixed column 8 is movably sleeved with a spring 11, the two ends of the spring 11 are elastically connected to the outer rotating ring 10 and one end of the slider 7 respectively, and the fixed bar 13 is in contact with the other end of the slider 7;

[0034] The spring 11 is responsible for being compressed by the slider 7 and generating a rebound force toward the axis of the packer 3, driving the slider 7 and the upper partition 5 to reset, and retracting the upper partition 5 into the interior of the packer 3, so that the fracturing hole 2 can drive the packer 3 to penetrate into the next layer of the coal seam.

[0035] The fixing bars 13 are arranged in six groups and are equidistantly distributed on the outer surface of the inner rotating ring 9 in a circumferential manner. The fixing bars 13 are located in the tangent direction of the inner rotating ring 9, and the angle between the fixing bars 13 and the axis of the fixing column 8 is an obtuse angle.

[0036] The six groups of fixed bars 13 correspond to the six groups of sliders 7 respectively. Driven by the rotating drum 12, the sliders 7 are driven to rotate while generating a thrust to move toward one side of the compression spring 11, so as to drive the upper partition 5 and the lower partition 6 to rotate while cutting by using the thrust to the outside.

[0037] The upper partition 5 and the lower partition 6 are both made of high manganese alloy steel, and the outer surfaces of the upper partition 5 and the lower partition 6 are coated with a wear-resistant and anti-oxidation coating;

[0038] The upper baffle 5 and the lower baffle 6 are made of high manganese alloy steel, which has high strength and can withstand the pressure generated by the fracturing fluid. The anti-oxidation coating prevents them from direct contact with water and prevents corrosion.

[0039] The upper baffle 5 or the lower baffle 6 can slide along the axis of the slider 7 and the fixed column 8 connected thereto. When the multiple sets of upper baffles 5 and lower baffles 6 are completely and equidistantly extended to the outside of the packer 3, the multiple sets of upper baffles 5 and lower baffles 6 can form a set of annular sealing layers.

[0040] The upper baffle 5 and the lower baffle 6 can move synchronously outward along the axis of the packer 3 under the action of the axial thrust generated by the fixed bar 13 driving the slider 7, and achieve cutting of the inner wall of the coal seam in coordination with their own rotation.

[0041] The upper and lower sets of rotating drums 12 and the inner rotating ring 9 are both rotatably mounted on the inner wall of the packer 3, and the rotating drum 12 and the inner rotating ring 9 are in contact with each other;

[0042] The rotating drum 12 is not directly fixedly connected to the inner rotating ring 9, but drives the slider 7 to rotate through the fixed bar 13, and transmits the rotational force to the upper partition 5, the inner rotating ring 9 and the outer rotating ring 10 through the slider 7. At the same time, the slider 7 can also slide on the outer surface of the fixed column 8, driving the upper partition 5 and the lower partition 6 to move outward.

[0043] Among them, one end of the fixing strip 13 is provided with a bend, which coincides with a set of radial lines of the packer 3 and leaves a gap with the inner wall of the outer swivel ring 10;

[0044] When the fixing bar 13 contacts the slider 7 , the bent portion thereof can just fit and abut against one side of the slider 7 , thereby increasing the force-bearing area of ​​the fixing bar 13 and reducing damage to the fixing bar 13 when contacting the slider 7 .

[0045] Working principle:

[0046] When the device is working, first, the injection pipe 1 is continuously placed downward along the wellhead and moved to the target depth, then the motor 14 is started to drive the gear 1 15 to rotate counterclockwise, and through the transmission of the gear 1 15 and the gear 2 16, the rotating drum 12 and the multiple sets of fixing bars 13 are driven to rotate clockwise;

[0047] In the upper compartment 18: the rotating drum 12 drives the fixed bar 13 to rotate, and pushes the slider 7 and the upper partition 5 to move along the axis of the fixed column 8, compressing the spring 11, and at the same time, drives the slider 7 and the upper partition 5 to rotate around the axis of the packer 3 as a whole, so that the upper partition 5 protrudes from the outer surface of the packer 3, and performs rotary cutting on the coal seam. As the coal seam is cut deeper, the fixed bar 13 can push the slider 7 to move outward along the axis of the fixed column 8, and continue to compress the spring 11;

[0048] In the lower compartment 19: another set of rotating drums 12 drives the fixed bar 13 to rotate, and pushes another set of sliders 7 and the lower partition 6 to move along the axis of the fixed column 8, compressing the spring 11, and at the same time, drives the slider 7 and the upper partition 5 to rotate around the axis of the packer 3 as a whole, so that the upper partition 5 protrudes from the outer surface of the packer 3, and performs rotary cutting on the coal seam. As the coal seam is cut deeper, the fixed bar 13 can push the slider 7 to move outward along the axis of the fixed column 8, and continue to compress the spring 11;

[0049] Then, the rotation speed of the upper baffle 5 and the lower baffle 6 is the same, and the displacement and speed of the upper baffle 5 and the lower baffle 6 along the axis of the fixed column 8 are also the same. As the upper baffle 5 and the lower baffle 6 gradually extend and rotate to cut the outer side of the packer 3, the upper baffle 5 and the lower baffle 6 quickly wedge into the grooves cut by them. Since there is a staggered angle of 30° around the axis of the upper baffle 5 and the lower baffle 6, the upper baffle 5 and the lower baffle 6 extending outward provide sufficient sealing for each of them.

[0050] Finally, the motor 14 is stopped to keep the upper baffle 5 and the lower baffle 6 in place, and the slider 7 is pushed by the fixing bar 13 to maintain. At this time, a seal is formed between the coal seams cut and sealed by the two groups of packers 3, and a large amount of fracturing fluid is pumped into the inner cavity of the injection pipe 1 through the pump on the ground. The fracturing fluid is ejected along the fracturing hole 2, and a large number of cracks are formed in the coal seam, and the coal seam gas is desorbed at the same time. When the fracturing fluid passes between the two groups of packers 3 and tries to be discharged through the upper baffle 5 and the lower baffle 6, the upper baffle 5 and the lower baffle 6 form a complete straight section on the inner wall of the coal seam through rotational cutting, which actually forms the first layer of sealing. Then, under the huge pressure formed by the filling of the fracturing fluid, the upper baffle 5 and the lower baffle 6 are pushed to abut against the inner wall of the coal seam more closely, further improving the sealing performance.

[0051] When the injection pipe 1 needs to go deeper into the next coal seam, the upper partition 5 and the lower partition 6 need to be retracted again. At this time, the motor 14 can be reversed to rotate the fixed bar 13 to a position away from the slider 7. Since the slider 7 is no longer subjected to the thrust of the fixed bar 13, it can drive the upper partition 5 or the lower partition 6 to reset under the action of the spring 11.

[0052] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A highly efficient coal seam fracturing device, comprising an injection pipe (1), a fracturing hole (2) and a packer (3), characterized in that: An upper compartment (18) and a lower compartment (19) are respectively provided inside the packer (3); an isolation groove (4) is provided on the outer surface of the packer (3); a plurality of groups of upper partitions (5) and lower partitions (6) are sealed and clamped to the inner wall of the isolation groove (4); and a sealing mechanism (17) is provided in each of the upper compartment (18) and the lower compartment (19); The sealing mechanism (17) comprises a motor (14), the output shaft of the motor (14) is mounted with a gear 1 (15), the opposite surfaces of the upper partition (5) and the lower partition (6) are fixedly connected with sliders (7), the inner walls of the upper partition (18) and the lower partition (19) are movably sleeved with outer rotating rings (10), the inner wall of the packer (3) is rotatably mounted with an inner rotating ring (9), a plurality of groups of fixed columns (8) are fixedly connected between the inner rotating ring (9) and the outer rotating ring (10), the inner walls of the upper partition (18) and the lower partition (19) are rotatably mounted with a rotating drum (12), the outer surface of the rotating drum (12) is fixedly mounted with a gear 2 (16), and both sides of the outer surface of the rotating drum (12) are fixedly connected with a plurality of groups of fixed bars (13), the fixed bars (13) are in contact with the sliders (7), and the upper partition (5) or the lower partition (6) can slide along the axis of the sliders (7) and the fixed columns (8) connected thereto.

2. The high-efficiency coal seam fracturing device according to claim 1 is characterized in that: The upper baffle (5) and the lower baffle (6) are of equal shape and size and are both fan-shaped. The contact surfaces of the upper baffle (5) and the lower baffle (6) are sealed and abutted. The number of the upper baffle (5) and the lower baffle (6) is set to six groups and are equidistantly distributed inside the packer (3). The upper baffle (5) and the lower baffle (6) are staggered and inclined at 30 degrees. The two groups of sealing mechanisms (17) are respectively connected to the upper baffle (5) and the lower baffle (6) in a transmission manner. The fracturing holes (2) are set to multiple groups and are distributed on the outer surface of the injection pipe (1). The packers (3) are set to multiple groups and are equidistantly distributed on the inner wall of the injection pipe (1). The gear one (15) is meshed with the gear two (16).

3. The high-efficiency coal seam fracturing device according to claim 2 is characterized in that: A spring (11) is movably sleeved on the outer surface of the fixing column (8), and two ends of the spring (11) are elastically connected to the outer rotating ring (10) and one end of the slider (7) respectively, and the fixing strip (13) abuts against the other end of the slider (7).

4. The high-efficiency coal seam fracturing device according to claim 3 is characterized by: The fixing bars (13) are arranged in six groups and are equidistantly distributed on the outer surface of the inner rotating ring (9) in a circular pattern. The fixing bars (13) are located in the tangent direction of the inner rotating ring (9), and the angle between the fixing bars (13) and the axis of the fixing column (8) is an obtuse angle.

5. The high-efficiency coal seam fracturing device according to claim 4 is characterized by: The upper baffle (5) and the lower baffle (6) are both made of high manganese alloy steel, and the outer surfaces of the upper baffle (5) and the lower baffle (6) are both coated with a wear-resistant and anti-oxidation coating.

6. The high-efficiency coal seam fracturing device according to claim 5, characterized in that: When the plurality of groups of upper baffles (5) and lower baffles (6) are completely and equidistantly extended toward the outside of the packer (3), the plurality of groups of upper baffles (5) and lower baffles (6) can form a group of annular sealing layers.

7. The high-efficiency coal seam fracturing device according to claim 6, characterized in that: The upper and lower groups of the rotating drum (12) and the inner rotating ring (9) are both rotatably mounted on the inner wall of the packer (3), and the rotating drum (12) and the inner rotating ring (9) are in contact with each other.

8. The high-efficiency coal seam fracturing device according to claim 7, characterized in that: One end of the fixing strip (13) is provided with a bend, the bend coincides with a set of radial lines of the packer (3), and a gap is left between the bend and the inner wall of the outer swivel ring (10).

Images