CN113006796B - Coal and contact symbiotic oil shale fracturing co-production method - Google Patents
Coal and contact symbiotic oil shale fracturing co-production method Download PDFInfo
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- CN113006796B CN113006796B CN202110399784.XA CN202110399784A CN113006796B CN 113006796 B CN113006796 B CN 113006796B CN 202110399784 A CN202110399784 A CN 202110399784A CN 113006796 B CN113006796 B CN 113006796B
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- 239000003245 coal Substances 0.000 title claims abstract description 124
- 239000004058 oil shale Substances 0.000 title claims abstract description 106
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- 238000005065 mining Methods 0.000 claims abstract description 57
- 239000011435 rock Substances 0.000 claims abstract description 55
- 238000006073 displacement reaction Methods 0.000 claims abstract description 28
- 230000003313 weakening effect Effects 0.000 claims abstract description 7
- 229910000831 Steel Inorganic materials 0.000 claims description 16
- 239000010959 steel Substances 0.000 claims description 16
- 238000007789 sealing Methods 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- 238000009434 installation Methods 0.000 claims description 9
- 210000004243 sweat Anatomy 0.000 claims description 6
- 238000011084 recovery Methods 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 8
- 230000006698 induction Effects 0.000 abstract description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 13
- 239000011707 mineral Substances 0.000 description 13
- 238000010586 diagram Methods 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- 238000005553 drilling Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 244000025254 Cannabis sativa Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C37/00—Other methods or devices for dislodging with or without loading
- E21C37/06—Other methods or devices for dislodging with or without loading by making use of hydraulic or pneumatic pressure in a borehole
- E21C37/12—Other methods or devices for dislodging with or without loading by making use of hydraulic or pneumatic pressure in a borehole by injecting into the borehole a liquid, either initially at high pressure or subsequently subjected to high pressure, e.g. by pulses, by explosive cartridges acting on the liquid
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/24—Methods of underground mining; Layouts therefor for oil-bearing deposits
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Abstract
The invention discloses a coal and contact symbiotic oil shale fracturing co-mining method, which is characterized in that a row of parallel fracturing drill holes are obliquely and forwardly constructed on a co-mining working face close to a coal seam top plate, penetrate through direct top oil shale above a coal seam and extend into an upper old top rock layer, a pulse fracturing system is arranged to generate a pulse fracturing network on the direct top oil shale, and a constant-displacement directional fracturing system generates directional hydraulic fractures on the old top rock layer. A rock placing port is arranged at the tail beam of the co-production support, and the coal cut by the coal cutter is transported by a front scraper conveyor; the directly pushed oil shale which is collapsed after the support is discharged from the rock discharge port and is transported by a rear scraper conveyor. The invention provides a coal seam direct roof oil shale fracturing weakening control idea of 'direct roof oil shale pulse fracturing and breaking + old roof directional fracturing induction mine fracturing rock', fully breaks the direct roof oil shale, obviously improves the caving property of the upper layer oil shale, reduces the caving lumpiness of the oil shale, and meets the requirement of the lumpiness discharged from a rock discharge port after the frame.
Description
Technical Field
The invention relates to the technical field of mining, in particular to a coal and contact symbiotic oil shale fracturing co-mining method.
Background
In China, a large number of mineral deposits are detected, wherein the mineral deposits of a single mineral species are relatively few, and most of the mineral deposits have one or more co-associated mineral products. The coal series is also called coal-bearing stratum and coal-bearing construction, and is a sedimentary rock series containing coal bed and having cause relation. The coal-series mineral resources refer to all mineral resources with cause relation in coal-bearing stratum, and include coal and coal-series co-associated mineral products. The traditional coal mine only mines coal resources, and has little or no consideration on coal series co-associated mineral resources, so that the great mineral resource waste is caused. Particularly, another mineral resource is directly existed on the upper part of the coal seam, such as a Yanan grass ditch coal mine, a Harbin ylang area and other coal seams, the oil shale is directly arranged on the top of the coal seam, and the problem of coordinated mining of the coal and coal series associated resources is more prominent.
For the condition that the direct top of the coal seam is the oil shale, if the lower coal seam is mined firstly, the oil shale on the direct top of the upper coal seam is broken and collapsed along with the mining of the coal seam, the occurrence state of the oil shale is damaged, and the oil shale cannot be mined; if the upper oil shale is mined firstly, the direct roof of the coal seam can be broken, and a mining system is difficult to arrange when the lower coal seam is mined, so that coal resources cannot be mined. Under the existing mining technical conditions, only one resource can be mined according to the mining value of the resource, and the other resource is wasted. Therefore, a method for co-mining coal and contact-co-generated oil shale needs to be developed, and the resource recovery rate is improved.
Aiming at the problem of co-mining of coal and contact symbiotic direct roof oil shale, the coal mine roof caving coal mining technology can be used for reference, namely, the direct roof oil shale on the upper part of a coal bed is discharged from a rack by adopting a roof caving coal method while the coal bed is mined, and is transported to the ground through two sets of transportation systems. However, because the oil shale is harder than the coal seam, the oil shale directly pushed against the coal seam after the support is difficult to fall in time along with the exploitation of the coal seam, and the falling block degree is large, so that the exploitation rate is extremely low. Therefore, the key technical problem of the core of co-mining the coal and the contact symbiotic direct roof oil shale in the form of caving coal is how to quickly and fully break the rock, so that the erected direct roof oil shale can be fully and timely caving, and the caving lumpiness is reduced.
The principle of hydraulic fracture weakening coal rock mass is that the stress state of the rock mass at the hole edge is changed by using the pressure of drilling water, so that the hole edge is cracked and cracks are expanded, and then the expansion of the hydraulic cracks is controlled by using the pressure of fracture water. The structural improvement of the coal rock mass is realized through the expansion of the main hydraulic pressure crack and the wing-shaped branch crack, and the overall mechanical property of the coal rock mass is weakened; meanwhile, the permeability of the coal rock mass is improved, water permeates into the coal rock mass through the cracks, so that the water content of the coal rock mass is increased, and the strength of the coal rock mass is weakened.
The directional fracturing is a safe and efficient directional rock breaking technology which guides the hydraulic fracture to directionally initiate and expand through directional measures such as pre-slotting and the like, forms a hydraulic fracture in a rock body along a preset direction, and realizes the directional fracture of the rock body. The pulse fracturing is a safe and efficient rock breaking technology which utilizes the action of pulse fatigue impact to generate a hydraulic pressure fracture network which is not controlled by ground stress in a rock body through a high-frequency pulse pump injection mode to fully break the rock body.
Disclosure of Invention
Aiming at the contradictions of mutual influence, resource waste and the like existing in independent mining of coal and contact symbiotic direct-propping oil shale and the difficult problem of timely and sufficient crushing of the oil shale in co-mining, the invention provides a coal and contact symbiotic oil shale fracturing co-mining method, which adopts a co-mining hydraulic support, a rock placing opening is arranged at the tail beam of the support, two scraper conveyors are matched, and coal cut by a coal mining machine is transported by a front scraper conveyor; the directly pushed oil shale which is collapsed after the support is discharged from the rock discharge port and is transported by a rear scraper conveyor.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
a coal and contact symbiotic oil shale fracturing co-production method comprises the following steps:
s1: a common mining support is arranged on a common mining working surface, and a coal mining machine, a front scraper conveyor and a rear scraper conveyor are sequentially arranged below the common mining support from front to back; installing and debugging a pulse fracturing high-pressure pump and a constant-displacement fracturing high-pressure pump in a stoping roadway; the pulse fracturing high-pressure pump and the constant displacement fracturing high-pressure pump are respectively connected with a first valve port and a second valve port of a three-way valve through high-pressure rubber pipes, a third valve port of the three-way valve is connected with one end of a variable joint through the high-pressure rubber pipes, a first switch valve is arranged on the high-pressure rubber pipe between the pulse fracturing high-pressure pump and the first valve port of the three-way valve, a second switch valve is arranged on the high-pressure rubber pipe between the constant displacement fracturing high-pressure pump and the second valve port of the three-way valve, and a pressure release valve is arranged on the high-pressure rubber pipe between the third valve port of the three-way valve and the variable joint;
s2: constructing a row of parallel fracturing drill holes obliquely in front of a co-production working face close to a coal seam roof, wherein the fracturing drill holes penetrate through direct top oil shale above the coal seam and extend into an old top rock layer above the direct top oil shale, the inclination angle of each fracturing drill hole is 45-75 degrees, the diameter of each fracturing drill hole is 32-75 mm, and the interval of the fracturing drill holes is determined according to the mechanical property of the coal seam roof;
s3: one end of the variable joint, which is far away from the high-pressure rubber pipe, is connected with an installation rod, one end of the installation rod, which is far away from the variable joint, is connected with a lower pulse fracturing packer, the lower pulse fracturing packer is connected with an upper pulse fracturing packer through a thin steel pipe, the upper pulse fracturing packer and the lower pulse fracturing packer are respectively connected with a hand pump through hole-sealing high-pressure thin hoses, and the lower pulse fracturing packer, the thin steel pipe and the upper pulse fracturing packer are sent to a designed fracturing position of direct oil shale through the installation rod;
s4: respectively expanding and sealing the upper pulse fracturing packer and the lower pulse fracturing packer by using a hand pump, then opening a first switch valve, closing a second switch valve and a pressure release valve, and starting a pulse fracturing high-pressure pump to perform direct top oil shale pulse fracturing;
s5: when the pulse fracturing is carried out for 15-20 min or the surface of the coal bed sweats for 4-6 min, closing the pulse fracturing high-pressure pump, opening a pressure relief valve to relieve pressure, withdrawing a lower pulse fracturing packer, a thin steel pipe and an upper pulse fracturing packer from a fracturing drill hole through an installation rod, and removing the connection between the installation rod and the lower pulse fracturing packer;
s6: one end of the mounting rod, which is far away from the variable joint, is connected with a directional fracturing hole packer, the directional fracturing hole packer is connected with a hand pump through a hole-sealing high-pressure fine hose, and the directional fracturing hole packer is sent into the old roof rock layer through the mounting rod;
s7: expanding and sealing the hole of the directional fracturing hole packer by using a hand pump, then opening a second switch valve, closing a first switch valve and a pressure release valve, and starting a constant-displacement fracturing high-pressure pump to perform constant-displacement directional fracturing on the old roof rock stratum;
s8: when the constant-displacement directional fracturing is carried out for 15-20 min or the surface of a coal seam sweats for 4-6 min, closing the constant-displacement fracturing high-pressure pump, opening a pressure relief valve to relieve pressure, then withdrawing the directional fracturing hole packer from a fracturing drill hole through an installation rod, and detaching the connection between the installation rod and the directional fracturing hole packer;
s9: respectively executing the steps S3-S8 in all the fracturing drill holes until the fracturing of all the fracturing drill holes is completed, and determining fracturing step distances according to fracturing weakening ranges;
s10: after fracturing is finished, the coal mining machine starts to cut coal;
s11: after the coal cutter cuts coal, the co-mining bracket immediately extends out of the front canopy to support the newly exposed upper direct top oil shale; after the coal mining machine passes through the coal mining machine, the co-mining bracket is moved forwards, and the side protection plate extends out to protect the front coal wall;
s12: the front scraper conveyor is moved forwards, and the front scraper conveyor is ensured to be linear after moving;
s13: determining rock releasing step distance according to the thickness of the oil shale directly jacked and the crushing degree of the oil shale, and releasing the crushed oil shale from a rock releasing port arranged at a tail beam of the co-production support;
s14: after directly ejecting the oil shale above the rear scraper conveyor, moving the rear scraper conveyor forwards;
s15: repeating the steps S10-S14 until the advancing length of the coal face reaches the fracturing step distance, and finishing the co-mining of the coal and the contact symbiotic oil shale in the current round;
s16: and repeating the steps S2-S15 until the recovery is finished.
Preferably, the high-pressure water generated by the pulse fracturing high-pressure pump in the step S4 sequentially passes through the high-pressure rubber tube, the three-way valve, the high-pressure rubber tube, the variable joint, the mounting rod and the lower pulse fracturing packer to enter the thin steel tube, and acts on the direct top oil shale through small holes uniformly distributed in the circumferential direction of the thin steel tube.
Preferably, the high-pressure water generated by the constant-displacement fracturing high-pressure pump in step S7 sequentially passes through the high-pressure rubber tube, the three-way valve, the high-pressure rubber tube, the variable joint and the mounting rod to enter a space between the directional fracturing hole packer and the bottom of the fracturing drilled hole, and acts on the old roof rock stratum.
Preferably, the fracture drill inclination angle is 60 °, the fracture drill diameter is 32mm, and the fracture drill spacing is 9 m.
Preferably, the fracturing step distance is 0.8-1.0 time of the horizontal projection length of the fractured borehole.
Compared with the prior art, the invention has the beneficial effects that:
(1) the invention provides a coal and contact symbiotic oil shale fracturing co-mining method, which is characterized in that when a coal bed is mined, top oil shale directly above the coal bed is discharged from a rock discharge port of a co-mining hydraulic support tail beam, so that co-mining of coal and co-associated oil shale is realized, the mining rate of mineral resources is improved, and resource waste is avoided.
(2) The invention provides a coal seam direct-roof oil shale fracturing weakening control idea of direct-roof oil shale pulse fracturing and breaking and old-roof directional fracturing induction ore fracturing rock breaking. Through pulse fracturing, a large-range hydraulic fracture network is generated in the immediate top oil shale, the immediate top oil shale is fully cut, the structure of the immediate top oil shale is improved, and meanwhile, the strength of the immediate top oil shale is reduced; and then cutting off the old top rock layer through directional hydraulic fracturing, so that the weight of the old top rock layer directly acts on the direct top oil shale, and the ore is induced to crush the rock. In addition, the hydraulic fracture network in a large range generated by pulse fracturing weakens the overall mechanical property of the oil shale directly on the top of the coal bed, and simultaneously, the permeability of the oil shale can be changed, so that the oil shale fully absorbs water and is wet, and the strength of the oil shale is further weakened. Through the comprehensive effects of the three aspects, the direct-propping oil shale is fully crushed, the caving property of the upper layer oil shale is obviously improved, the caving lumpiness of the oil shale is reduced, and the requirement of the lumpiness discharged from the rock placing port after the frame is met.
Drawings
For a clearer explanation of the embodiments or technical solutions of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for a person skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a plan view of coal co-production with contacting of co-produced oil shale fractures;
FIG. 2 is a cross-sectional view taken at line I-I of FIG. 1;
FIG. 3 is a schematic diagram of pulse fracturing hole sealing;
FIG. 4 is a schematic diagram of constant displacement directional fracturing hole sealing;
FIG. 5 is a schematic diagram of a pulse fracturing system connection;
fig. 6 is a schematic diagram of a connection of a constant displacement directional fracturing system.
In the figure: 1. co-mining a working face; 2. stoping the roadway; 3. co-production of a scaffold; 4. a goaf behind the rack; 5. a coal seam; 6. directly ejecting oil shale; 7. old topping; 8. a base plate; 9. a coal mining machine; 10. a front flight conveyor; 11. a rear flight conveyor; 12. placing a rock opening; 13. fracturing and drilling; 14. pulse fracture-pressing net; 15. directional hydraulic fracturing; 16-1, pulse fracturing packer below; 16-2, an upper pulse fracturing packer; 17. directional fracturing hole packer; 18. sealing the hole of the high-pressure fine hose; 19. mounting a rod; 20. a variable joint; 21. a pressure relief valve; 22. a high-pressure rubber hose; 23. a three-way valve; 24. a first on-off valve; 25. a second on-off valve; 26. a pulse fracturing high pressure pump; 27. a constant displacement frac high pressure pump; 28. a hand pump; 29-thin steel tube.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1-6, a certain mine in shanxi is taken as an example to illustrate the implementation process of the coal and contact symbiotic oil shale fracturing co-production method in detail. The coal seam mined by the mine is single and stable in structure, the average coal thickness is 3.24m, the immediate roof is gray black oil shale, the average thickness is 4.04m, the old roof is gray white fine-grained sandstone, and the average thickness is 3.07 m. Because the oil shale has high taste and is directly above the coal bed, the coal and the oil shale can be considered to be mined together.
The specific implementation steps are as follows:
s1: a common mining support 3 is installed on a common mining working face 1, and a coal mining machine 9, a front scraper conveyor 10 for transporting coal and a rear scraper conveyor 11 for transporting oil shale are sequentially installed below the common mining support 3 from front to back; installing and debugging a pulse fracturing high-pressure pump 26 and a constant-displacement fracturing high-pressure pump 27 on the stoping roadway 2; the pulse fracturing high-pressure pump 26 and the constant displacement fracturing high-pressure pump 27 are respectively connected with a first valve port and a second valve port of the three-way valve 23 through a high-pressure rubber pipe 22, a third valve port of the three-way valve 23 is connected with one end of the variable joint 20 through the high-pressure rubber pipe 22, a first switch valve 24 is arranged on the high-pressure rubber pipe 22 between the pulse fracturing high-pressure pump 26 and the first valve port of the three-way valve 23, a second switch valve 25 is arranged on the high-pressure rubber pipe 22 between the constant displacement fracturing high-pressure pump 27 and the second valve port of the three-way valve 23, and a pressure release valve 21 is arranged on the high-pressure rubber pipe 22 between the third valve port of the three-way valve 23 and the variable joint 20;
s2: a row of parallel fracturing drill holes 13 are obliquely constructed in the front of the part, close to the top plate of the coal seam 5, of the co-production working face 1, the fracturing drill holes 13 penetrate through the direct top oil shale 6 above the coal seam 5 and extend into the old top rock layer 7 above the direct top oil shale 6, the inclination angle of each fracturing drill hole 13 is 60 degrees, the diameter of each fracturing drill hole 13 is 32mm, and the distance between every two fracturing drill holes 13 is 9 m; the drilling depth is 11 m;
s3: one end of the variable joint 20, which is far away from the high-pressure rubber pipe 22, is connected with a mounting rod 19, one end of the mounting rod 19, which is far away from the variable joint 20, is connected with a lower pulse fracturing packer 16-1, the lower pulse fracturing packer 16-1 is connected with an upper pulse fracturing packer 16-2 through a thin steel pipe 29, the upper pulse fracturing packer and the lower pulse fracturing packer are respectively connected with a hand pump 28 through a hole sealing high-pressure thin hose 18, and the lower pulse fracturing packer 16-1, the thin steel pipe 29 and the upper pulse fracturing packer 16-2 are sent to a designed fracturing position of the direct top oil shale 6 through the mounting rod 19;
s4: respectively expanding and sealing the upper pulse fracturing packer and the lower pulse fracturing packer by using a hand pump 28, then opening a first switch valve 24, closing a second switch valve 25 and a pressure release valve 21, and starting a pulse fracturing high-pressure pump 26 to perform pulse fracturing on the direct top oil shale 6; high-pressure water generated by the pulse fracturing high-pressure pump 26 sequentially passes through the high-pressure rubber tube 22, the three-way valve 23, the high-pressure rubber tube 22, the variable joint 20, the mounting rod 19 and the lower pulse fracturing packer 16-1 to enter the thin steel tube 29, and acts on the direct top oil shale 6 through small holes uniformly distributed on the periphery of the thin steel tube 29 to generate a pulse fracturing net 14;
s5: when the pulse fracturing is carried out for 15-20 min or the surface of the coal seam 5 sweats for 4-6 min, closing the pulse fracturing high-pressure pump 26, opening the pressure relief valve 21 to relieve the pressure, withdrawing the lower pulse fracturing packer 16-1, the thin steel pipe 29 and the upper pulse fracturing packer 16-2 from the fractured borehole 13 through the mounting rod 19, and removing the connection between the mounting rod 19 and the lower pulse fracturing packer 16-1;
s6: one end of the mounting rod 19, which is far away from the variable joint 20, is connected with a directional fracturing hole packer 17, the directional fracturing hole packer 17 is connected with a hand pump 28 through a hole-sealing high-pressure fine hose 18, and the directional fracturing hole packer 17 is sent into the old roof rock layer 7 through the mounting rod 19;
s7: expanding and sealing the hole of the directional fracturing hole packer 17 through a hand pump 28, then opening a second switch valve 25, closing a first switch valve 24 and a pressure release valve 21, and starting a constant-displacement fracturing high-pressure pump 27 to perform constant-displacement directional fracturing on the old roof rock layer 7; high-pressure water generated by the constant-displacement fracturing high-pressure pump 27 sequentially passes through the high-pressure rubber tube 22, the three-way valve 23, the high-pressure rubber tube 22, the variable joint 20 and the mounting rod 19 to enter a space between the directional fracturing hole packer 17 and the bottom of the fracturing drill hole 13, and acts on the old roof rock layer 7 to generate a directional hydraulic fracture 15;
s8: when the constant-displacement directional fracturing is carried out for 15-20 min or the surface of the coal seam 5 sweats for 4-6 min, closing the constant-displacement fracturing high-pressure pump 27, opening the pressure relief valve 21 to relieve the pressure, then withdrawing the directional fracturing hole packer 17 from the fracturing drill hole 13 through the mounting rod 19, and detaching the connection between the mounting rod 19 and the directional fracturing hole packer 17;
s9: respectively executing the steps S3-S8 in all the fracturing drill holes 13 until the fracturing of all the fracturing drill holes 13 is completed, and determining fracturing steps according to fracturing weakening ranges; the fracturing step distance is 0.8-1.0 time of the horizontal projection length of the fracturing drill hole 13.
S10: after fracturing is finished, the coal cutter 9 starts to cut coal;
s11: after the coal mining machine 9 cuts coal, the co-mining bracket 3 immediately extends out of the front canopy to support the newly exposed upper direct top oil shale 6; after the coal mining machine 9 passes through the coal mining machine, the co-mining bracket 3 is moved forwards, and the side protection plate extends out to protect the front coal wall;
s12: the front scraper conveyor 10 is moved forwards, and the front scraper conveyor 10 is ensured to be linear after moving;
s13: determining rock placing step distances according to the thickness and the crushing degree of the direct top oil shale 6, and discharging the crushed oil shale from a rock placing port 12 arranged at a tail beam of the co-production support 3;
s14: after directly pushing the oil shale 6 above the rear scraper conveyor 11, moving the rear scraper conveyor forwards;
s15: repeating the steps S10-S14 until the advancing length of the coal face reaches the fracturing step distance, and finishing the co-mining of the coal and the contact symbiotic oil shale in the current round;
s16: and repeating the steps S2-S15 until the recovery is finished.
The invention provides a coal and contact symbiotic oil shale fracturing co-mining method, which is characterized in that when a coal bed is mined, top oil shale directly above the coal bed is discharged from a rock discharge port of a co-mining hydraulic support tail beam, so that co-mining of coal and co-associated oil shale is realized, the mining rate of mineral resources is improved, and resource waste is avoided. The invention provides a coal seam direct-roof oil shale fracturing weakening control idea of direct-roof oil shale pulse fracturing and breaking and old-roof directional fracturing induction ore fracturing rock breaking. Through pulse fracturing, a large-range hydraulic fracture network is generated in the immediate top oil shale, the immediate top oil shale is fully cut, the structure of the immediate top oil shale is improved, and meanwhile, the strength of the immediate top oil shale is reduced; and then cutting off the old top rock layer through directional hydraulic fracturing, so that the weight of the old top rock layer directly acts on the direct top oil shale, and the ore is induced to crush the rock. In addition, the hydraulic fracture network in a large range generated by pulse fracturing weakens the overall mechanical property of the oil shale directly on the top of the coal bed, and simultaneously, the permeability of the oil shale can be changed, so that the oil shale fully absorbs water and is wet, and the strength of the oil shale is further weakened. Through the comprehensive effects of the three aspects, the direct-propping oil shale is fully crushed, the caving property of the upper layer oil shale is obviously improved, the caving lumpiness of the oil shale is reduced, and the requirement of the lumpiness discharged from the rock placing port after the frame is met.
Claims (4)
1. A coal and contact symbiotic oil shale fracturing co-production method is characterized by comprising the following steps:
s1: a common mining support (3) is installed on a common mining working face (1), and a coal mining machine (9), a front scraper conveyor (10) and a rear scraper conveyor (11) are sequentially installed below the common mining support (3) from front to back; installing and debugging a pulse fracturing high-pressure pump (26) and a constant-displacement fracturing high-pressure pump (27) in a stoping roadway (2); the pulse fracturing high-pressure pump (26) and the constant displacement fracturing high-pressure pump (27) are respectively connected with a first valve port and a second valve port of a three-way valve (23) through a high-pressure rubber pipe (22), a third valve port of the three-way valve (23) is connected with one end of a variable joint (20) through the high-pressure rubber pipe (22), a first switch valve (24) is arranged on the high-pressure rubber pipe (22) between the pulse fracturing high-pressure pump (26) and the first valve port of the three-way valve (23), a second switch valve (25) is arranged on the high-pressure rubber pipe (22) between the constant displacement fracturing high-pressure pump (27) and the second valve port of the three-way valve (23), and a pressure release valve (21) is arranged on the high-pressure rubber pipe (22) between the third valve port of the three-way valve (23) and the variable joint (20);
s2: a row of parallel fracturing drill holes (13) are obliquely and forwardly constructed at a position, close to a top plate of a coal seam (5), of a co-production working face (1), the fracturing drill holes (13) penetrate through direct top oil shale (6) above the coal seam (5) and extend into an old top rock layer (7) above the direct top oil shale (6), the inclination angle of each fracturing drill hole (13) is 45-75 degrees, the diameter of each fracturing drill hole (13) is 32-75 mm, and the distance between every two fracturing drill holes (13) is determined according to the mechanical property of the top plate of the coal seam (5);
s3: one end of the variable joint (20), which is far away from the high-pressure rubber pipe (22), is connected with a mounting rod (19), one end of the mounting rod (19), which is far away from the variable joint (20), is connected with a lower pulse fracturing packer (16-1), the lower pulse fracturing packer (16-1) is connected with an upper pulse fracturing packer (16-2) through a thin steel pipe (29), the upper pulse fracturing packer and the lower pulse fracturing packer are respectively connected with a hand pump (28) through a hole-sealing high-pressure thin hose (18), and the lower pulse fracturing packer (16-1), the thin steel pipe (29) and the upper pulse fracturing packer (16-2) are sent into a designed fracturing position of the direct top oil shale (6) through the mounting rod (19);
s4: the upper pulse fracturing packer and the lower pulse fracturing packer are respectively expanded and sealed by a hand pump (28), then a first switch valve (24) is opened, a second switch valve (25) and a pressure release valve (21) are closed, and a pulse fracturing high-pressure pump (26) is started to perform pulse fracturing on the direct top oil shale (6); high-pressure water generated by the pulse fracturing high-pressure pump (26) sequentially passes through the high-pressure rubber pipe (22), the three-way valve (23), the high-pressure rubber pipe (22), the variable joint (20), the mounting rod (19) and the lower pulse fracturing packer (16-1) to enter the thin steel pipe (29), and acts on the direct jacking oil shale (6) through small holes uniformly distributed in the circumferential direction of the thin steel pipe (29);
s5: closing the pulse fracturing high-pressure pump (26) when the pulse fracturing is 15-20 min or the surface of the coal seam (5) sweats for 4-6 min,
opening a pressure relief valve (21) to relieve pressure, then withdrawing a lower pulse fracturing packer (16-1), a thin steel pipe (29) and an upper pulse fracturing packer (16-2) from a fracturing drill hole (13) through an installation rod (19), and removing the connection between the installation rod (19) and the lower pulse fracturing packer (16-1);
s6: one end of the mounting rod (19) far away from the variable joint (20) is connected with the directional fracturing hole packer (17), the directional fracturing hole packer (17) is connected with a hand pump (28) through a hole-sealing high-pressure fine hose (18), and the directional fracturing hole packer (17) is sent into the old roof rock stratum (7) through the mounting rod (19);
s7: expanding and sealing the hole of the directional fracturing hole packer (17) through a hand pump (28), then opening a second switch valve (25), closing a first switch valve (24) and a pressure release valve (21), and starting a constant-displacement fracturing high-pressure pump (27) to perform constant-displacement directional fracturing on the old roof rock stratum (7);
s8: when the constant-displacement directional fracturing is carried out for 15-20 min or the surface of the coal seam (5) sweats for 4-6 min, closing the constant-displacement fracturing high-pressure pump (27), opening the pressure relief valve (21) to relieve pressure, then withdrawing the directional fracturing hole packer (17) from the fracturing drill hole (13) through the mounting rod (19), and detaching the connection between the mounting rod (19) and the directional fracturing hole packer (17);
s9: respectively executing the steps S3-S8 in all the fracturing drill holes (13) until fracturing of all the fracturing drill holes (13) is completed, and determining fracturing step distances according to fracturing weakening ranges;
s10: after fracturing is finished, the coal cutter (9) starts to cut coal;
s11: after the coal cutter (9) cuts coal, the co-mining bracket (3) immediately extends out of the front canopy to support the newly exposed upper direct roof oil shale (6); after the coal mining machine (9) passes through the coal mining machine, the co-mining bracket (3) moves forwards, and the side protection plate extends out to protect the front coal wall;
s12: the front scraper conveyor (10) is moved forwards, and the front scraper conveyor (10) is ensured to be linear after moving;
s13: determining rock placing step distances according to the thickness and the crushing degree of the direct top oil shale (6), and discharging the crushed oil shale from a rock placing opening (12) arranged at a tail beam of the co-production support (3);
s14: after directly ejecting the oil shale (6) above the discharging device, moving a rear scraper conveyor (11) forwards;
s15: repeating the steps of S10-S14 until the advancing length of the coal face reaches the fracturing step distance, and finishing the co-mining of the coal of the current round and the contact symbiotic oil shale;
s16: and repeating the steps S2-S15 until the recovery is finished.
2. The coal and contact symbiotic oil shale fracturing co-production method according to claim 1, characterized by comprising the following steps: high-pressure water generated by the constant-displacement fracturing high-pressure pump (27) in the step S7 sequentially passes through the high-pressure rubber pipe (22), the three-way valve (23), the high-pressure rubber pipe (22), the variable joint (20) and the mounting rod (19) to enter a space between the directional fracturing hole packer (17) and the bottom of the fracturing drill hole (13) and act on the old roof rock stratum (7).
3. The coal and contact symbiotic oil shale fracturing co-production method according to claim 1, characterized by comprising the following steps: the dip angle of the fracturing drill holes (13) is 60 degrees, the diameter of the fracturing drill holes (13) is 32mm, and the distance between the fracturing drill holes (13) is 9 m.
4. The coal and contact symbiotic oil shale fracturing co-production method according to claim 1, characterized by comprising the following steps: the fracturing step distance is 0.8-1.0 time of the horizontal projection length of the fracturing drill hole (13).
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2303694C1 (en) * | 2006-03-28 | 2007-07-27 | Государственное образовательное учреждение высшего профессионального образования "Санкт-Петербургский государственный горный институт имени Г.В. Плеханова (технический университет)" | Method for thick coal bed development |
| CN102606128A (en) * | 2011-12-29 | 2012-07-25 | 新奥气化采煤有限公司 | Oil shale mining method and device |
| CN107387052A (en) * | 2017-09-13 | 2017-11-24 | 吉林大学 | A kind of oil shale in-situ recovery method |
| CN108678747A (en) * | 2018-04-28 | 2018-10-19 | 中国矿业大学 | A kind of method and apparatus of pulsed water fracturing control Top coal caving characteristic |
| CN108894787A (en) * | 2018-05-31 | 2018-11-27 | 中国矿业大学 | Leave the pressure break release method of ore pillar stress concentration in Overburden gob area |
| CN109958421A (en) * | 2019-03-19 | 2019-07-02 | 中国矿业大学(北京) | Top relief construction method and drilling machine are cut in a kind of precracking hydraulic fracturing |
-
2021
- 2021-04-14 CN CN202110399784.XA patent/CN113006796B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2303694C1 (en) * | 2006-03-28 | 2007-07-27 | Государственное образовательное учреждение высшего профессионального образования "Санкт-Петербургский государственный горный институт имени Г.В. Плеханова (технический университет)" | Method for thick coal bed development |
| CN102606128A (en) * | 2011-12-29 | 2012-07-25 | 新奥气化采煤有限公司 | Oil shale mining method and device |
| CN107387052A (en) * | 2017-09-13 | 2017-11-24 | 吉林大学 | A kind of oil shale in-situ recovery method |
| CN108678747A (en) * | 2018-04-28 | 2018-10-19 | 中国矿业大学 | A kind of method and apparatus of pulsed water fracturing control Top coal caving characteristic |
| CN108894787A (en) * | 2018-05-31 | 2018-11-27 | 中国矿业大学 | Leave the pressure break release method of ore pillar stress concentration in Overburden gob area |
| CN109958421A (en) * | 2019-03-19 | 2019-07-02 | 中国矿业大学(北京) | Top relief construction method and drilling machine are cut in a kind of precracking hydraulic fracturing |
Non-Patent Citations (1)
| Title |
|---|
| 煤与油页岩共生互层条件下联合开采方法探索;高维智;《煤炭工程》;20120731(第7期);全文 * |
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