CN113565457A - Broken soft coal seam large-dip-angle long drilling construction process - Google Patents
Broken soft coal seam large-dip-angle long drilling construction process Download PDFInfo
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- CN113565457A CN113565457A CN202111013631.3A CN202111013631A CN113565457A CN 113565457 A CN113565457 A CN 113565457A CN 202111013631 A CN202111013631 A CN 202111013631A CN 113565457 A CN113565457 A CN 113565457A
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/22—Rods or pipes with helical structure
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/16—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor using gaseous fluids
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F17/00—Methods or devices for use in mines or tunnels, not covered elsewhere
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F7/00—Methods or devices for drawing- off gases with or without subsequent use of the gas for any purpose
Abstract
The invention relates to the technical field of large-inclination-angle drilling construction, and discloses a large-inclination-angle long drilling construction process for a broken soft coal bed, which comprises the following steps: preparing drilling equipment, wherein the drilling equipment comprises a drilling machine, a drill rod, a drill bit, a hole sealing pipe, an air compressor, an air storage tank and an orifice deslagging mechanism, and the orifice deslagging mechanism comprises a dust separator, a sprayer and a barrel type dust remover; step two, drilling, wherein the drilling machine drives the drill rod and the drill bit to rotate so as to drill a hole; and step three, deslagging, wherein in the drilling process, compressed air generated by the operation of the air compressor is sent into the sprayer after passing through the air storage tank, a water supply pipeline is additionally connected to the upper part of the sprayer, water entering the sprayer is atomized by the compressed air and then enters the bottom of the hole through the drill rod, particles with large particle sizes in the air carrying the coal slag directly drop at the hole opening, and fine dust is adsorbed and removed through the cylindrical dust remover. The invention can carry out slag discharge on drill cuttings in the drill hole in the drilling process.
Description
Technical Field
The invention relates to the technical field of large-inclination-angle drilling construction, in particular to a large-inclination-angle long drilling construction process for a broken soft coal bed.
Background
The gas pre-pumping of the low-permeability broken soft outburst coal seam in China has not formed a set of perfect and feasible technology and matched drilling tools all the time, because the hole forming in the broken soft coal seam is difficult, especially in the region with high ground stress, the drilling construction is very difficult, and the hole accidents such as hole spraying, hole collapse, drill jamming and the like are easy to occur, so that the hole forming rate of the drilled hole is low, and the hole forming depth is shallow. Until now, in most practical applications of coal mines in China, the depth of a broken soft coal seam gas extraction drill hole is more than 30-40m and generally not more than 60m, and the safety production of the coal mine is severely restricted.
Aiming at the problems of difficult pore forming, shallow pore forming depth, poor drainage effect and the like existing in the common rotary drilling by using water as a flushing medium for drilling and adopting a broken soft coal seam, the problem of difficult pore forming of the broken soft coal seam by drilling along the stratum is gradually solved by adopting an air drilling process in the coal mine in China, and the research and development of the wind pressure air drilling equipment and the development of the matched process in the broken soft coal seam, which are one of the projects of 'coal mine gas comprehensive treatment and research and development by key technology and equipment', are carried out by the national development and improvement committee of the institute of western security in 2006, the method makes important progress in the aspects of development of drilling tools of drilling machines, optimization of related matched equipment, matched process development and the like, however, the theoretical analysis only aims at horizontal or near-horizontal drilling of the coal mine, the large-inclination downward long drilling process is not researched, and a theoretical system of the large-inclination downward long drilling process is not established.
The reserve of the large inclination angle coal seam in China approximately accounts for 15% -20% of the total reserve of coal, and the annual output of the large inclination angle coal seam accounts for about 10% of the total output of coal in China. In the western part of China, the coal seam accounts for about 30% of the total coal reserves, more than 50% of mines are mined with the coal seam, such as Sichuan, Chongqing, Yunnan, Guizhou, Xinjiang, Gansu, Ningxia and the like of main coal producing provinces (regions), and the coal seam with a large inclination angle is the main coal mining seam of a plurality of mining regions or mines; similarly, the specific gravity of the coal seam left in the old mining area of the east is also higher, for example, Shandong Yanzhou mining area, Hebei Chenchentai mining area and mining area of \28390, Anhui Huainan and Huaibei mining area, Jiangsu Xuzhou mining area and the like, many mines in the mining areas have to be changed from the mining of the coal seam with relatively superior conditions to the mining of the coal seam with a complex large inclination angle. Therefore, the key technology for solving the problem of gas control of the large-inclination broken soft coal seam is an urgent task aiming at the large-inclination downward long drilling process and theoretical analysis.
Wherein the slag discharge capacity is one of the main factors influencing the drilling. If once the drill cuttings in the drill hole are accumulated, the frictional resistance among the hole wall, the drill cuttings and the drill rod is increased, and after the drill cuttings in the drill hole are accumulated to a certain degree, the rotating torque of the drill cannot overcome the resistance, namely the drill embracing phenomenon occurs. Therefore, normal drilling requires that the continuously generated drill cuttings be completely and quickly discharged out of the hole, so as to avoid accumulation of the drill cuttings in the hole, which requires sufficient slag discharge capacity.
Disclosure of Invention
The invention aims to provide a large-inclination-angle long drilling construction process for a broken soft coal seam so as to discharge slag from drill cuttings in a drilling hole in the drilling process.
In order to achieve the purpose, the invention adopts the following technical scheme: the large-dip-angle long drilling construction process for the broken soft coal seam comprises the following steps of:
preparing drilling equipment, wherein the drilling equipment comprises a drilling machine, a drill rod, a drill bit, a hole sealing pipe, an air compressor, an air storage tank and an orifice deslagging mechanism, and the orifice deslagging mechanism comprises a dust separator, a sprayer and a barrel type dust remover;
step two, drilling, wherein the drilling machine drives the drill rod and the drill bit to rotate so as to drill a hole;
and step three, deslagging, wherein in the drilling process, compressed air generated by the operation of an air compressor is sent into an atomizer after passing through an air storage tank, a water supply pipeline is additionally connected to the upper part of the atomizer, water entering the atomizer is atomized by the compressed air and then enters the bottom of a hole through a drill rod, air carrying coal slag reaches an orifice through an annular space between a hole wall and the drill rod, large-particle-size particles in the air carrying the coal slag directly drop at the orifice, and fine dust is adsorbed and removed through a cylindrical dust remover.
The principle and the advantages of the scheme are as follows: in the scheme, the drill cuttings generated in the drilling process can be discharged through the orifice slag discharging mechanism in the drilling process, so that the problem that the resistance cannot be overcome by the rotation torque of the drilling machine due to the accumulation of the drill cuttings in the drilled holes is avoided, and the phenomenon of drill embracing is caused.
In addition, during drilling, compressed air generated by the operation of the air compressor is delivered into the sprayer after passing through the air storage tank, a water supply pipeline is additionally connected to the upper part of the sprayer, water entering the sprayer is atomized by the compressed air and then enters the bottom of the hole through the drill rod 9, and the effects of deslagging, cooling the drill bit and preventing drilling and burning are achieved; the air carrying the cinder reaches the orifice through the annular space between the hole wall and the drill rod, and at the orifice, because the flow rate is reduced, the large-particle-size particles directly drop at the orifice, and fine dust is sucked out by negative pressure and is removed dust through a cylindrical dust remover, so that the purpose of reducing dust pollution is achieved.
The scheme can carry out slag discharge on the generated drilling cuttings in the drilling process, and avoids the drilling cuttings from being blocked in the drilling hole to influence smooth drilling and the drilling depth. And can absorb tiny dust at the in-process of arranging the sediment in this scheme to avoid the dust to fly upward and produce the condition of dust pollution.
Preferably, as an improvement, the broken soft coal seam large-inclination long drilling construction process according to claim 1 is characterized in that: settling velocity of drill cutting particles generated by drilling
In the formula utThe settling velocity of the drill cuttings particles, in m/s, g-acceleration of gravity, in m/s2(ii) a Rho s-density of drill cuttings in kg/m3(ii) a Rho a-density of air in kg/m3(ii) a ds-average particle size of drill cuttings, in m;
for discharging particles of drill cuttingsThe minimum wind flow velocity is:
in the formula ua-minimum wind velocity in m/s for the discharge of drill cuttings particles; zeta-friction coefficient between drilling cutting and hole wall, taking I; theta-borehole inclination angle.
Since the particles fall freely from a static state in the fluid medium, the particles are accelerated to a certain speed and then become equal-speed sedimentation, the speed at this time is called the sedimentation speed of the particles, and the size of the sedimentation speed is related to the material property and the particle size of the particles. Obviously, for individual drill cuttings particles, the wind velocity must be greater than their settling velocity to be blown out.
Meanwhile, according to the pneumatic transmission principle, the balance of the slag discharge amount and the slag yield amount is ensured during actual drilling, namely, the non-blocking condition is met. For drill cutting particles of a given size, the velocity of the air exiting the borehole should first be such that the minimum settling velocity is met, while at the same time the friction between the particles and the wall of the borehole and the potential energy created by the inclination of the borehole are overcome. Generally speaking, drill cuttings belong to coarse particles whose reynolds number Re of the fluid medium (e.g. air) relative to the wind flow of the particles at constant velocity of sedimentation is >500, under which the sedimentation velocity of the drill cuttings particles is adapted to newtonian law of resistance.
According to the calculation formula of the settling velocity in the scheme, the factors such as friction with the hole wall, potential energy overcoming and the like are considered, and the minimum wind flow velocity of the discharged drill chip particles can be obtained. The drill cuttings can be guaranteed to be blown out of the drill hole only when the drill cuttings meet the minimum wind flow speed, and therefore sufficient slag discharging capacity is guaranteed.
Preferably, as an improvement, in order to ensure that the drill cuttings in the drill hole are not blocked, the air flow speed should satisfy the following conditions:
Since ua represents only the velocity of the air stream at which the particles can slide on the walls of the hole, it is a critical value. A large amount of particles are continuously generated in the actual construction drill hole, and the blocking possibly caused by the mutual blocking effect between the particles, so that the drill cuttings in the drill hole can be prevented from being blocked according to the minimum wind speed calculated in the scheme, and the slag discharge capacity of the drill cuttings is further improved.
Preferably, as an improvement, the wind speed u for ensuring normal slag discharge is selected as ua、ubMaximum value of (d), u ═ max { u { (u) }a,ub}。
In the scheme, u is taken according to the wind speed u for ensuring normal slag dischargea、ubMaximum value of (i.e., u ═ max { u ═ max }a,ubThe basic requirements of slag discharge can be met.
Preferably, as an improvement, the supply air flow rate of the supply air into the borehole is calculated according to the following formula: q is less than or equal to 60VK (lambda D2-D2) pi/4, wherein Q is air supply flow and the unit is m 3/min; d is the pore diameter, and the unit is m; d is the diameter of the drill rod and the unit is m; v is upward return wind speed, and the unit is m/s; k is a coefficient and takes a value of 1-1.5; and lambda is the hole expanding coefficient and is between 1 and 1.1.
In the scheme, the air supply flow and the air supply pressure are intensively researched aiming at the underground air drilling process parameters. The air supply flow is based on the suspension state of the coal powder in the drill hole, and the air supply flow is calculated according to the formula in the scheme by combining the migration characteristic of the coal powder in the horizontal hole, so that the air supply flow required by ensuring enough slag discharge capacity can be obtained.
Preferably, as an improvement, the specific value of the borehole diameter expansion coefficient λ is determined according to the value of the firmness coefficient f of the constructed coal seam: when f is more than or equal to 0.2 and less than or equal to 0.5, the lambda is 1.05-1.1; when f is more than or equal to 0.5 and less than or equal to 0.8, the lambda is 1-1.05; when f is more than or equal to 0.8, the lambda is 1.
In the scheme, the result tends to be more accurate due to the hole drilling and expanding coefficient, so that the specific value is determined according to the firmness coefficient f of the constructed coal bed.
Preferably, as an improvement, the loss of resistance Δ P of the compressed air is equal to Δ Pa+△Psac+△Ps+△Pt+△PzThe air supply pressure is greater than delta P, wherein delta P is the resistance loss of compressed air; delta Pa-resistance loss to transport of the pure air flow from the bottom of the hole to the orifice; delta Psac-accelerating the cuttings from the bottom of the hole to a certain velocity with additional loss of drag; delta Ps-additional drag losses by conveying the coal slag at a certain speed; delta Pt-loss of pressure wind resistance at the drill bit; delta PzLoss of resistance to the flow of air inside the drill rod, Δ Pa、△Psac、△Ps、△PtAnd Δ PzThe units of (A) are Pa.
In the scheme, a certain wind speed is required for air drilling slag removal, and various resistance losses of wind flow are overcome to enable the wind flow to reach the wind speed. The process of carrying the drill cuttings from the hole bottom to the hole opening by the compressed air can be approximately equal to the pneumatic conveying in the pipe, and according to the gas-solid two-phase flow theory in the pipe, various energy consumed by the air flow and the drill cuttings is compensated by the pressure energy of the air flow.
The pressure loss in air drilling mainly includes accelerated pressure loss, frictional pressure loss, drill cuttings levitation lifting pressure loss, and local pressure loss. The air drilling air supply pressure is based on overcoming various flow resistances in the circulation process, namely the air supply pressure is greater than the sum of pressure losses.
Preferably, as an improvement, the bit pressure value of the drill bit is 2-6 Mpa, and the rotating speed of the drill bit is 90-160 r/min.
Drilling the broken soft coal seam to determine a bit pressure value according to the drilling depth and the condition in the hole, wherein the bit pressure value is generally 2-6 Mpa; the linear velocity is preferably 90-160 r/min, and different rotating speeds are selected according to the different calibers, the hardness of coal rock strata and the difference of production states.
Preferably, as an improvement, the drill rod is a triangular spiral drill rod, the triangular spiral drill rod is provided with three edge surfaces, and a spiral groove is formed in the triangular spiral drill rod.
The characteristics of stirring the coal dust in the hole by the aid of the triangular spiral drill rod and assisting in discharging slag are utilized, the drilling slag is discharged by a drilling machine and compressed air, and the problem that the slag discharging effect is poor or the drilling is blocked in the hole, so that the hole forming property is poor is effectively solved. The triangular spiral structure improves the slag discharging efficiency of the drill rod, can effectively solve the drilling clamping and burying accidents caused by hole collapse and hole collapse by rotating the drill rod, repeatedly washing the hole and the like when the drill meets a broken coal seam, and can effectively improve the directional drilling depth of the broken coal seam.
Preferably, as an improvement, one end of the cylinder type dust remover is communicated with a slag discharge pipeline, and one side of the cylinder type dust remover is communicated with a drainage pipeline connected with coal mine gas.
Can get into the cinder in the cylinder dust remover to get rid of in this scheme, can also collect remaining gas through drainage tube way simultaneously.
Drawings
FIG. 1 is a schematic layout view of an orifice deslagging mechanism in an embodiment of a broken soft coal seam large-inclination long drilling construction process.
FIG. 2 is a front view of a drill rod in an embodiment of the broken soft coal seam large-inclination long drilling construction process.
Fig. 3 is a cross-sectional view at B-B in fig. 2.
Detailed Description
The following is further detailed by way of specific embodiments:
reference numerals in the drawings of the specification include: the device comprises a hole sealing pipe 1, a first rubber mat 2, a dust separator 3, a second rubber mat 4, a bolt 5, a gasket 6, a nut 7, a guider 8, a drill rod 9, a water braid 10, an atomizer 11, a cylindrical dust remover 12, an exhaust flange 13, an air storage tank 14, an air compressor 15, a water supply pipe 16, a rubber pipe assembly 17, a drainage pipeline 18, a slag discharge pipeline 19 and a coal wall 20.
The embodiment is basically as shown in the attached figure 1: the large-dip-angle long drilling construction process for the broken soft coal seam comprises the following steps of:
preparing drilling equipment, wherein the drilling equipment comprises a drilling machine, a drill rod 9, a drill bit, a hole sealing pipe 1, an air compressor 15, an air storage tank 14 and an orifice deslagging mechanism, and the orifice deslagging mechanism comprises a dust separator 3, a sprayer 11 and a cylindrical dust remover 12;
step two, drilling, wherein the drilling machine drives the drill rod 9 and the drill bit to rotate so as to drill a hole;
and step three, deslagging, wherein in the drilling process, compressed air generated by the operation of an air compressor 15 is sent into an atomizer 11 after passing through an air storage tank 14, a water supply pipeline 16 is additionally connected to the upper part of the atomizer 11, water entering the atomizer 11 is atomized by the compressed air and then enters the bottom of a hole through a drill rod 9, air carrying coal cinder reaches a hole opening through an annular space between a hole wall and the drill rod 9, large-particle-size particles in the air carrying the coal cinder directly drop at the hole opening, and fine dust is adsorbed and removed through a cylindrical dust remover 12.
In this embodiment, the air storage tank 14 is a horizontal air storage tank 14, the air compressor 15 is communicated with a storage pipe, the air storage tank 14 is communicated with the sprayer 11, a water braid 10 is connected between the sprayer 11 and the drill rod 9, and a rubber pipe assembly 17 is communicated between the sprayer 11 and the water braid 10.
Insert on the coal wall 20 and seal a hole pipe 1, be equipped with first cushion 2 and second cushion 4 on sealing a hole pipe 1, it has dust separator 3 to seal a hole pipe 1 go up the intercommunication, and dust separator 3 is located between first cushion 2 and the second cushion 4, still be connected with director 8 on sealing a hole pipe 1, director 8 passes through bolt 5 and nut 7 and connects, and be equipped with packing ring 6 between director 8 and the sealing a hole pipe 1, packing ring 6 can play sealed effect.
The dust separator 3 is communicated with a cylinder type dust remover 12, the right end of the cylinder type dust remover 12 is communicated with a slag discharge pipeline 19, the upper side of the cylinder type dust remover 12 is communicated with a drainage pipeline 18 connected with coal mine gas, the drainage pipeline 18 is fixedly assembled and welded through an exhaust flange 13, and the cylinder type dust remover 12 and the sprayer 11 are both communicated with a water supply pipe 16 in the embodiment.
As shown in fig. 2 and 3, the drill rod in this embodiment is a triangular spiral drill rod 9, the triangular spiral drill rod 9 has three edge surfaces, and a spiral groove is formed in the triangular spiral drill rod 9, and the end surface of the drill rod 9 shown in fig. 3 is designed to be approximately triangular, so that the drill rod has a good hole protection function and a good drill chip disturbance capacity, and is beneficial to enhancing the stability of the well wall and improving the movement capacity of drill chips. The characteristics of precipitating coal dust in the holes and assisting in slag discharging are stirred by the triangular spiral drill rod 9, the drilling slag is discharged by a drilling machine and compressed air, and the problem of poor hole forming property caused by poor slag discharging effect or drill jamming in the holes is effectively prevented. The triangular spiral structure improves the slag discharging efficiency of the drill rod 9, and can effectively solve the drilling jamming and burying accidents caused by hole collapse and hole collapse by rotating the drill rod 9, repeatedly washing the hole and the like when the drill meets the broken coal seam, and can effectively improve the directional drilling depth of the broken coal seam.
According to the principle of pneumatic transmission, whether the drill cuttings in the drill hole can be blown out by compressed air or not depends on the wind speed in the drill hole firstly, and then the inclination angle of the drill hole, the particle size of the drill cuttings, the solid-gas mixing ratio (the ratio of the slag yield of the drill hole in unit time to the compressed air flow) and the like. The dip angle of the drill hole is designed according to the occurrence condition of the coal seam and the drainage requirement; the particle size of the drill cuttings is mainly related to the damage degree of the coal seam, whether holes and spray holes are broken or not, the form of the drill bit, the drilling speed and the rotating speed of the drill bit and the like; the solid-gas mixing ratio is mainly related to the slag yield and compressed air flow of the drill hole in unit time; the wind speed in the drill hole is related to the pressure of supplied wind, the resistance coefficient of the drill hole and the drill hole, and the like. The larger the wind speed is, the stronger the slag discharge capacity is; the smaller the solid-gas mixing ratio and the particle size of the drill cuttings, the easier the slag discharge is; slagging is more difficult to drill down than up. When the factors such as geology, equipment, the diameter of a drill hole, the inclination angle of the drill hole, the drilling speed and the like are relatively unchanged, the air supply parameters become main influence factors of the wind power slag discharge capacity.
Drilling process parameters
1) Minimum wind speed
Settling velocity of drill cutting particles generated by drilling
In the formula utThe settling velocity of the drill cuttings particles, in m/s, g-acceleration of gravity, in m/s2(ii) a Rho s-density of drill cuttings in kg/m3(ii) a Rho a-density of air in kg/m3(ii) a ds-average particle size of drill cuttings, in m;
the minimum wind flow velocity to expel the drill cuttings particles is:
in the formula ua-minimum wind velocity in m/s for the discharge of drill cuttings particles; zeta-friction coefficient between drilling cutting and hole wall, taking I; theta is the inclination angle of the borehole, theta is taken as minus when drilling upward, and theta is taken as plus when drilling downward.
Since the particles fall freely from a static state in the fluid medium, the particles are accelerated to a certain speed and then become equal-speed sedimentation, the speed at this time is called the sedimentation speed of the particles, and the size of the sedimentation speed is related to the material property and the particle size of the particles. Obviously, for individual drill cuttings particles, the wind velocity must be greater than their settling velocity to be blown out.
Meanwhile, according to the pneumatic transmission principle, the balance of the slag discharge amount and the slag yield amount is ensured during actual drilling, namely, the non-blocking condition is met. For drill cutting particles of a given size, the velocity of the air exiting the borehole should first be such that the minimum settling velocity is met, while at the same time the friction between the particles and the wall of the borehole and the potential energy created by the inclination of the borehole are overcome. Generally speaking, drill cuttings belong to coarse particles whose reynolds number Re of the fluid medium (e.g. air) relative to the wind flow of the particles at constant velocity of sedimentation is >500, under which the sedimentation velocity of the drill cuttings particles is adapted to newtonian law of resistance.
U aboveaIt is a critical value, which is simply the velocity of the air stream as the particles slide over the walls of the hole. A large amount of particles are continuously generated in the actual drilled hole, and the mutual inhibition thereof may cause clogging. In order to ensure that the drill cuttings in the drill hole are not blocked, the air flow speed of the drill hole also meets the following conditions:
Therefore, the wind speed u for ensuring normal slag discharge should be taken as ua、ubMaximum value of (i.e., u ═ max { u ═ max }a,ubThe basic requirements of slag discharge can be met.
2) Air supply flow parameter
Aiming at the technical parameters of the underground air drilling, the air supply flow and the air supply pressure are intensively researched. The air supply flow rate is based on the suspension state of the coal powder in the drill hole, and can be calculated according to the following formula by combining the migration characteristic of the coal powder in the horizontal hole: q is less than or equal to 60VK (lambda D)2-d2) Pi/4, where Q is the air supply flow and is given in m3Min; d is the pore diameter, and the unit is m; d is the diameter of the drill rod and the unit is m; v is upward return wind speed, and the unit is m/s; k is a coefficient and takes a value of 1-1.5; and lambda is the hole expanding coefficient and is between 1 and 1.1. Wherein the hole drilling and expanding coefficient makes the result more accurate, and the specific value is determined according to the value of the firmness coefficient f of the constructed coal bed: when f is more than or equal to 0.2 and less than or equal to 0.5, the lambda is 1.05-1.1; when f is more than or equal to 0.5 and less than or equal to 0.8, the lambda is 1-1.05; when f is more than or equal to 0.8, the lambda is 1.
3) Pressure of air supply
The air drilling slag removal requires certain wind speed, and various resistance losses of the wind flow are overcome to enable the wind flow to reach the wind speed. The process of carrying the drill cuttings from the hole bottom to the hole opening by the compressed air can be approximately equal to the pneumatic conveying in the pipe, and according to the gas-solid two-phase flow theory in the pipe, various energy consumed by the air flow and the drill cuttings is compensated by the pressure energy of the air flow. The pressure loss in air drilling mainly includes accelerated pressure loss, frictional pressure loss, drill cuttings levitation lifting pressure loss, and local pressure loss. The air supply pressure of the air drilling is larger than the sum of pressure losses by taking the overcoming of various flow resistances in the circulation process as a criterion, and the calculation formula is as follows: Δ P ═ Δ Pa+△Psac+△Ps+△Pt+△PzThe air supply pressure is greater than delta P, wherein delta P is the resistance loss of compressed air; delta Pa-resistance loss to transport of the pure air flow from the bottom of the hole to the orifice; delta Psac-accelerating the cuttings from the bottom of the hole to a certain velocity with additional loss of drag; delta Ps-additional drag losses by conveying the coal slag at a certain speed; delta Pt-loss of pressure wind resistance at the drill bit; delta PzLoss of resistance to the flow of air inside the drill rod, Δ Pa、△Psac、△Ps、△PtAnd Δ PzThe units of (A) are Pa.
Second, corollary equipment
400 screw drill rods with phi 73, 5 concave drill bits with phi 94 three wings, 1 reaming drill bit with phi 133, 5 hole sealing pipes with phi 127 and 1 sleeve of an orifice slag discharging mechanism. Other devices are shown in tables 1-1, tables 1-2, tables 1-3:
TABLE 1-1LDZYW-3200 all-hydraulic tunnel drilling machine technical parameters
| Serial number | Parameter name | Parameter value | Remarks for |
|
| 1 | Output torque (N.m) | 3200-800 | ||
| 2 | Output speed (r/min) | 70-240 | ||
| 3 | Rated voltage | 660/ |
||
| 4 | Motor power (KW) | 45 | ||
| 5 | Certificate number for | 17007H | ||
| 6 | Physical dimension (mm) | 2225×1190×1380mm | (Length. times. Width. times. height) | |
| 7 | Net weight (Kg) | 2240 | ||
| 8 | Explosion- | Mining | ||
| 9 | Safety mark number | MED100036 |
TABLE 1-2MLGF13/7-75G technical parameters of air compressor
| Serial number | Parameter name | Parameter value | Remarks for |
|
| 1 | Displacement (m)3/min) | 9.8 | ||
| 2 | Exhaust pressure (MPa) | 1.25 | ||
| 3 | Rated voltage | 380/ |
||
| 4 | Motor power (KW) | 75 | ||
| 5 | Certificate number for | K20851 | ||
| 6 | Physical dimension (mm) | 2965×1200×1591mm | (Length. times. Width. times. height) | |
| 7 | Net weight (Kg) | 2390 | ||
| 8 | Explosion- | Mining | ||
| 9 | Safety mark number | MEH050025 |
TABLE 1-3C-1.0/1.3 technical parameters of gas storage tank
| Serial number | Parameter name | Parameter value | Remarks for |
|
| 1 | Design pressure (MPa) | 1.35 | ||
| 2 | Design temperature (. degree.C.) | 150 | ||
| 3 | Form of | Single layer | ||
| 4 | Type of support | |
||
| 5 | | 217010J8420182131 | ||
| 6 | Physical dimension (mm) | 1950×720×605mm | (Length. times. Width. times. height) | |
| 7 | Net weight (Kg) | 370 | ||
| 8 | Volume m3 | 1.0 | ||
| 9 | Class of pressure vessels | Class I |
Three, large dip angle down long drilling process parameters
1) Weight on bit
Drilling the broken soft coal seam to determine a bit pressure value according to the drilling depth and the condition in the hole, wherein the bit pressure value is generally 2-6 Mpa; under the conditions of drilling stratum such as abrupt, loose and broken, soft and hard interbedded and strong abrasiveness, bending and over-diameter of the drilled hole, and the like, the pressure of the joint development coal rock and the productive form should be properly reduced; the new drill bit after primary grinding can obtain high drilling speed by adopting normal drilling pressure. During drilling, as the drill bit is worn down, the drilling speed is reduced, and the drilling pressure is gradually and stably increased.
2) Rotational speed
The linear velocity is preferably 90-160 r/min, and different rotating speeds are selected according to different calibers, coal rock layer hardness and occurrence difference; when drilling hard and weak abrasive stratum, fracture broken stratum, soft and hard interbedded layer and attitude steep and inclined stratum, properly reducing the rotating speed; drilling in soft rock stratum, the rotating speed should be limited; the drilling structure and the drilling tool are reasonable in grading, the clearance between the drilling rod and the hole wall is small, and the high-speed drilling machine is suitable for adopting high rotating speed; when the drilling structure is complex, the diameter is changed more, and the annular clearance is large, the stability of the rotation of the drilling tool is poor, and the high rotating speed is not suitable for drilling.
3) Air quantity
According to the above, the wind speed u for ensuring normal slag discharge is the minimum wind flow speed u for discharging drill cutting particlesaAnd ensuring that cuttings in the borehole do not clog ubU-max { ua, ub } can meet the basic requirement of slag discharge. The influence of the drill hole inclination angle on the minimum wind flow speed of slag discharge is small, and the smaller the angle is, the more the requirement on the minimum wind flow speed isIn order to combine with the industrial test, the calculation takes down hole inclination angles of 30 ° and 35 ° respectively as shown in tables 2-1 and 2-2.
TABLE 2-1 drilling (inclination angle 30 degree) slag discharge speed calculation table
TABLE 2-2 drilling (inclination angle 35 °) slag-tapping calculation table
When the inclination angles of the drill holes are 30 degrees and 35 degrees, the drilling speed is calculated by 1.2m/min, and the air density is 2kg/m3When the average particle diameter of the drill cuttings is 0.002m, the deslagging speed is maximum and is 13.1m/s, and the deslagging air volume is 4.3m3Min; the air density is 6kg/m3When the average particle size of the drill cuttings is 0.008m, the deslagging speed is minimum and is 10.5m/s, and the deslagging air volume is 3.5m3/min。
4) Wind pressure
According to the theoretical analysis and the combination of the technological parameters of the downward long drilling with the large inclination angle, in the actual drilling process, the deviation exists between the theoretical calculation and the actual drilling parameters, and the wind pressure required by the actual drilling is slightly higher than the theoretical calculation result under the general condition. Through the analysis of reference related documents and actual drilling data, the relation between the wind supply pressure and the drilling depth required for keeping normal or good slag discharge state in the drilling hole is as follows:
in the formula: l-the borehole depth in m; p-minimum air supply pressure required for normal slag discharge, and the unit is MPa.
The wind pressure required by different hole depth sections is 0-50 m to 0.44MPa, 50-100 m to 0.53MPa, 100-150 m to 0.61MPa and 150-200 m to 0.67MPa through preliminary calculation, and the large-inclination downward long drilling process test and construction are guided at present.
The foregoing is merely an example of the present invention and common general knowledge in the art of designing and/or characterizing particular aspects and/or features is not described in any greater detail herein. It should be noted that, for those skilled in the art, without departing from the technical solution of the present invention, several variations and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.
Claims (10)
1. The large-dip-angle long drilling construction process of the broken soft coal seam is characterized by comprising the following steps of: the method comprises the following steps:
preparing drilling equipment, wherein the drilling equipment comprises a drilling machine, a drill rod, a drill bit, a hole sealing pipe, an air compressor, an air storage tank and an orifice deslagging mechanism, and the orifice deslagging mechanism comprises a dust separator, a sprayer and a barrel type dust remover;
step two, drilling, wherein the drilling machine drives the drill rod and the drill bit to rotate so as to drill a hole;
and step three, deslagging, wherein in the drilling process, compressed air generated by the operation of an air compressor is sent into an atomizer after passing through an air storage tank, a water supply pipeline is additionally connected to the upper part of the atomizer, water entering the atomizer is atomized by the compressed air and then enters the bottom of a hole through a drill rod, air carrying coal slag reaches an orifice through an annular space between a hole wall and the drill rod, large-particle-size particles in the air carrying the coal slag directly drop at the orifice, and fine dust is adsorbed and removed through a cylindrical dust remover.
2. The broken soft coal seam large-inclination long drilling construction process according to claim 1, characterized in that: settling velocity of drill cutting particles generated by drilling
In the formula utThe settling velocity of the drill cuttings particles, in m/s, g-acceleration of gravity, in m/s2(ii) a Rho s-density of drill cuttings in kg/m3(ii) a Rho a-density of air in kg/m3(ii) a ds-average particle size of drill cuttings, in m; the minimum wind flow velocity to expel the drill cuttings particles is:
in the formula ua-minimum wind velocity in m/s for the discharge of drill cuttings particles; zeta-friction coefficient between drilling cutting and hole wall, taking I; theta-borehole inclination angle.
3. The broken soft coal seam large-inclination long drilling construction process according to claim 2, characterized in that: to ensure that the drill cuttings in the drill hole are not blocked, the air flow speed of the drill hole should meet the following conditions:
4. The broken soft coal seam large-inclination long drilling construction process according to claim 3, characterized in that: the wind speed u for ensuring normal slag discharge should be takena、ubMaximum value of (d), u ═ max { u { (u) }a,ub}。
5. The broken soft coal seam large-inclination long drilling construction process according to claim 1, characterized in that: the air supply flow to the borehole is calculated according to the following formula: q is less than or equal to 60VK (lambda D)2-d2) Pi/4, where Q is the air supply flow and is given in m3Min; d is the pore diameter, and the unit is m; d is the diameter of the drill rod and the unit is m; v is upward return wind speed, and the unit is m/s; k is a coefficient and takes a value of 1-1.5; and lambda is the hole expanding coefficient and is between 1 and 1.1.
6. The broken soft coal seam large-inclination long drilling construction process according to claim 5, characterized in that: the specific value of the borehole diameter expansion coefficient lambda is determined according to the value of the firmness coefficient f of the constructed coal seam: when f is more than or equal to 0.2 and less than or equal to 0.5, the lambda is 1.05-1.1; when f is more than or equal to 0.5 and less than or equal to 0.8, the lambda is 1-1.05; when f is more than or equal to 0.8, the lambda is 1.
7. The broken soft coal seam large-inclination long drilling construction process according to claim 1, characterized in that: resistance loss delta P of compressed air is equal to delta Pa+△Psac+△Ps+△Pt+△PzThe air supply pressure is greater than delta P, wherein delta P is the resistance loss of compressed air; delta Pa-resistance loss to transport of the pure air flow from the bottom of the hole to the orifice; delta Psac-accelerating the cuttings from the bottom of the hole to a certain velocity with additional loss of drag; delta Ps-additional drag losses by conveying the coal slag at a certain speed; delta Pt-loss of pressure wind resistance at the drill bit; delta PzLoss of resistance to the flow of air inside the drill rod, Δ Pa、△Psac、△Ps、△PtAnd Δ PzThe units of (A) are Pa.
8. The broken soft coal seam large-inclination long drilling construction process according to claim 1, characterized in that: the bit pressure value of the drill bit is 2-6 Mpa, and the rotating speed of the drill bit is 90-160 r/min.
9. The broken soft coal seam large-inclination long drilling construction process according to claim 1, characterized in that: the drill rod is a triangular spiral drill rod, the triangular spiral drill rod is provided with three edge surfaces, and a spiral groove is formed in the triangular spiral drill rod.
10. The broken soft coal seam large-inclination long drilling construction process according to claim 1, characterized in that: one end of the cylinder type dust remover is communicated with a slag discharge pipeline, and one side of the cylinder type dust remover is communicated with a drainage pipeline connected with coal mine gas.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201771541U (en) * | 2010-07-19 | 2011-03-23 | 安阳鑫龙煤业(集团)果园煤业有限责任公司 | Negative-pressure dust remover |
| CN105971517A (en) * | 2016-06-23 | 2016-09-28 | 中煤科工集团西安研究院有限公司 | Underground progressive gas pre-extraction and directional hole drilling system and method for broken and soft coal seam |
| CN211287550U (en) * | 2019-10-28 | 2020-08-18 | 上海亦又新能源科技有限公司 | Drill rod connecting mechanism suitable for gas extraction of soft coal seam |
-
2021
- 2021-08-31 CN CN202111013631.3A patent/CN113565457A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201771541U (en) * | 2010-07-19 | 2011-03-23 | 安阳鑫龙煤业(集团)果园煤业有限责任公司 | Negative-pressure dust remover |
| CN105971517A (en) * | 2016-06-23 | 2016-09-28 | 中煤科工集团西安研究院有限公司 | Underground progressive gas pre-extraction and directional hole drilling system and method for broken and soft coal seam |
| CN211287550U (en) * | 2019-10-28 | 2020-08-18 | 上海亦又新能源科技有限公司 | Drill rod connecting mechanism suitable for gas extraction of soft coal seam |
Non-Patent Citations (11)
| Title |
|---|
| 周建成等: "煤矿用新型三棱螺旋钻杆研制及应用", 《煤矿机械》, vol. 41, no. 11, pages 135 - 137 * |
| 李拥军: "煤层钻孔施工中综合防尘技术研究", 《淮南职业技术学院学报》 * |
| 李拥军: "煤层钻孔施工中综合防尘技术研究", 《淮南职业技术学院学报》, vol. 5, no. 03, 30 September 2005 (2005-09-30), pages 5 - 6 * |
| 殷新胜等: "松软煤层中风压空气钻进技术与装备", 《煤矿安全》 * |
| 殷新胜等: "松软煤层中风压空气钻进技术与装备", 《煤矿安全》, no. 07, 10 July 2012 (2012-07-10), pages 63 - 65 * |
| 殷新胜等: "松软突出煤层中风压空气钻进工艺及配套装备", 《煤炭科学技术》 * |
| 殷新胜等: "松软突出煤层中风压空气钻进工艺及配套装备", 《煤炭科学技术》, vol. 37, no. 09, 25 September 2009 (2009-09-25), pages 72 - 74 * |
| 王力: "煤矿井下松软煤层空气雾化钻进用雾化器的研制", 《煤炭科学技术》 * |
| 王力: "煤矿井下松软煤层空气雾化钻进用雾化器的研制", 《煤炭科学技术》, vol. 44, no. 08, 24 August 2016 (2016-08-24), pages 150 - 155 * |
| 王建: "顺层瓦斯钻孔风力排渣模拟研究", 《山东煤炭科技》 * |
| 王建: "顺层瓦斯钻孔风力排渣模拟研究", 《山东煤炭科技》, no. 12, 28 December 2019 (2019-12-28), pages 104 - 106 * |
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