The Yolk coal rock formation downward hole pumping and mining pressure relief mash gas construction method
Technical field
The present invention relates to the gas pumping relief construction method in the coal seam group mining process, more specifically say so for the gas pumping relief construction method in low ventilative, high gas, outstanding, the weak seam recovery process.
Background technology
For the improvement of gas disaster is a great difficult problem in the process of coal mining, to the mine of coal seam group mining, has adopted the exploitation topping mostly both at home and abroad.During the exploitation topping, must carry out gas to protected seam and take out in advance, it mainly is the construction layer-through drilling that gas is taken out in advance, and for the following guarantor's layer that does not have or do not possess construction base plate lane, takes out in advance to layer-through drilling down with regard to constructing.Otherwise protected seam can not get abundant release after the topping exploitation on the one hand; On the other hand, after protected seam was adopted release, gas pressure relief poured out to topping, even if adopt " Y " shape to ventilate, gas exceeding limit in work plane and the return badly influences mine safety production in the time of still can causing the topping exploitation.
At present, to layer-through drilling enforcement was only arranged in the minority mine down, concrete form of construction work is in work progress, mainly adopts ZY-300, SGZ-300 type rig, is that power, common pressure wind are medium with the electricity, blast 1-2Mpa, bore diameter 74mm directly constructs at the bottom of the hole, behind the pore-forming after the perforate, direct following 2 cun sleeve pipe 10m are with the manual sealing of hole 10m of cement.This sealing of hole mode sealing of hole is not tight, gas leakage is serious, causes the gas pumping weak effect.Moreover, this mode mainly is at the original coal and rock that is not subjected to mining influence, and the yolk coal rock stratum is owing to changed by mining influence, original coal and rock, and it is big that the crack becomes, soundness reduces greatly, the coal and rock deliquescing, existing less to the layer-through drilling job practices down because of blast, cause hole internal drainage, deslagging difficulty, also because of coal and rock is soft, the hole that collapses in the work progress is serious.In fact, this existing mode can not directly be constructed in the yolk coal rock stratum.
Summary of the invention
The present invention is for avoiding above-mentioned existing in prior technology weak point; a kind of Yolk coal rock formation downward hole pumping and mining pressure relief mash gas construction method is provided; to solve the distinguished and admirable gas exceeding limit problem of coal-face return airway; be implemented in and in the topping recovery process protected coal seam that covers no base plate lane down carried out gas and take out in advance; improve mash gas extraction concentration; to improve resource utilization, guarantee efficient, the safe working of coal-face.
The geological conditions that the present invention is directed to the yolk coal rock stratum provides effective down to the job practices of layer-through drilling, makes down to layer-through drilling to obtain implementing in the yolk coal rock stratum.
Technical solution problem of the present invention adopts following technical scheme:
The characteristics of Yolk coal rock formation downward hole pumping and mining pressure relief mash gas construction method of the present invention are the gob side entry retaining sections at the topping work plane, are provided with down to layer-through drilling, take out in advance by to layer-through drilling gas being carried out in the protection coal seam of covering down down.
The characteristics of the inventive method also are:
For being at first to form the reaming section downwards down from the seat earth of gob side entry retaining to the construction of layer-through drilling, inner sleeve is finished guard aperture down in the reaming section, slip casting forms the sealing of hole section between the outer wall of inner sleeve and rock, and further the construction of layer-through drilling is to carry out in inner sleeve downwards.
The upper end mouth of pipe of inner sleeve is higher than described down to the aperture of layer-through drilling, and the sealing of hole section to the bottom to inner sleeve, the aperture of layer-through drilling, adopts high pressure hole-sealing pump injection hole sealing from down.
The degree of depth of inner sleeve is not less than 20m.
Lag behind topping work plane 20-30m construction to layer-through drilling down.
In layer-through drilling was arranged in protected coal seam release scope, being ribbon by the pumping and mining pressure relief radius at the bottom of the hole of layer-through drilling arranged that evenly spacing is 15-20m at the bottom of the hole down down.
For adopting the high-pressure blast deslagging to creep into to the construction of layer-through drilling down, blast is 7-9MPa.
Compared with the prior art, beneficial effect of the present invention is embodied in:
1, the present invention passes through under the construction of actual mining face gob-side entry retaining section to layer-through drilling; in the time of maximizing the exploitation of extraction topping; protected seam promptly covers the gas pressure relief in coal seam down; improve the topping exploitation effect; make the back production under the present low gas state of high Gassy Coal Face; reduce gas simultaneously and gush out, guarantee the back production of work plane safety to stope.
2, the present invention is directed to the following of yolk coal rock stratum and under the job practices of holing makes, in construction, be difficult for collapsing hole, Completion of Drilling Hole rate height to boring.
3, can adopt the KQJ120 down-the-hole drill for following construction to boring in the inventive method, this type of rig is the negative number of degrees hole of construction specially, and angle of depression maximum can reach-90 °.In recovery process to topping; carry out gas to the protection coal seam construction drill of covering down takes out in advance; pre-draining borehole must cover entire working surface; so do not have under the situation in base plate lane in the protection coal seam of covering down; bore angle must have different angles, and the inventive method can satisfy 0 °~-90 ° pitch angle adjustable extent of this construction fully.Simultaneously, the rig in the present invention construction is to be power with the high-pressure blast, adopts the high-pressure blast deslagging to creep into, and drilling construction speed improves 2-3 doubly than traditional speed of application, becomes the porosity height, is difficult for bury drills, the drilling depth 80m that can construct.
3, the present invention by in exploitation when covering the coal seam under cover under the high prominent coal seam construction of high gas to layer-through drilling, covering the coal seam under making does not need construct base plate lane and layer-through drilling, greatly reduces shape and adopts cost, has accelerated the driving progress.
4, the mode of high pressure hole-sealing pump injection hole sealing of the present invention has been guaranteed sealing quality, has effectively improved gas pumping and utilization rate.
Description of drawings
Fig. 1 is that topping is exploited under the work plane gob side entry retaining to layer-through drilling plane of arrangement figure in the inventive method.
Fig. 2 arranges sectional drawing to layer-through drilling under the topping exploitation work plane gob side entry retaining in the inventive method.
Fig. 3 is that topping is exploited under the work plane gob side entry retaining to the layer-through drilling working drawing in the inventive method.
Fig. 4 is a sealing of hole slip casting profile in the inventive method.
Number in the figure: 1 gob side entry retaining, 2 times are to layer-through drilling, 3 goafs, 4 coal-faces, 5 main air intake lanes, 6 auxiliary air intake lanes, 7 inner sleeves, 8 drilling rods, 9 toppings, 10 protected seams, 11 scars, 12 borings, 13 hole sealing tubes, 14 Grouting Pipe.
Below by the specific embodiment, the invention will be further described in conjunction with the accompanying drawings.
The specific embodiment
Referring to Fig. 1, work plane will carry out the secondary filling with packing material to air way at stoping period and stay the lane after going into operation, and as the return aircourse of this face, utilize two lane air intakes of working face extraction direction, realize " Y " type draft type of " two advance a time "
The main composition that stays lane section filler is the concrete lotion, and filling is wide * and height is 3.0m * 1.8m, to head-to-foot, adopts the novel filling pump of German BSM1002E to carry out filling.To adopting distortion tunnel, back, adopt to add and mend canopy supporting, planted agent's mode simultaneously, guarantee the gob side entry retaining section.
Fig. 1, shown in Figure 2, gob side entry retaining 1 are in the work exploitation process, the tunnel of reserving along the goaf; Drilling construction angle to layer-through drilling 2 is negative down, and passes the boring that the coal seam enters base plate by roof; The space that no longer safeguard later on for back production in goaf 3; Coal-face 4 is the ribs that carry out back production in stope; Main air intake lane 5 be big intake airflow the tunnel of process; Auxiliary air intake lane 6 be less intake airflow the tunnel of process.
Fig. 3, shown in Figure 4, inner sleeve 7 are pipe fittings of putting in boring; Drilling rod 8 is the instrument of construction drill; Topping 9 is for eliminating or weaken outstanding or the bump dangerous coal seam or the ore bed of exploitation earlier in adjacent coal seam; Protected seam 10 is in protected coal seam, topping 9 exploitation backs
As shown in Figure 1,, be provided with down, by down carrying out gas and take out in advance to 2 pairs of the layer-through drillings protection coal seams of covering down to layer-through drilling 2 in the gob side entry retaining section of topping work plane.This mode effectively extraction is adopted a large amount of gas pressure reliefs of adjacent layer afterwards, and the minimizing gas pressure relief pours out to stope and guarantees the safe back production of work plane.
Corresponding measure in the concrete construction also comprises:
Referring to Fig. 2, Fig. 3, owing to produce distortion and soft at seat earth behind the seam mining, the drilling construction hole that easily collapses, therefore, for selecting the KQJ120 down-the-hole drill for use to the construction of layer-through drilling 2 down, at first use 153mm major diameter compact bit to form the reaming section downwards from the seat earth of gob side entry retaining 1, inner sleeve 7 is finished guard aperture down in the reaming section, the degree of depth of inner sleeve 7 is not less than 20m, slip casting forms the sealing of hole section between the outer wall of inner sleeve 7 and rock, and then the drill bit that changes 94-108mm in inner sleeve 7 further boring downwards at the bottom of the hole, form down to layer-through drilling 2.The sealing of hole section requires closely knit air tight, and the sealing of hole section to the bottom to inner sleeve 7, the aperture of layer-through drilling 2, adopts high pressure hole-sealing pump injection hole sealing from down.In order to protect the aperture not impaired, the upper end mouth of pipe of inner sleeve 7 should suitably be higher than following aperture to layer-through drilling 2.
In the exploitation process, before and after work plane, can produce a press belt, suffer the slope bad because of being subjected to mining influence, should lag behind work plane 20-30m construction to layer-through drilling 2 down for avoiding pore-forming.Simultaneously, also owing to lag behind the work plane construction, be subjected to the work plane mining influence, the coal seam roof and floor is sent out distortion crack, back, and the coal rock layer water content significantly reduces, and during drilling construction, water accumulating volume effectively reduces.
In concrete the enforcement; down in layer-through drilling 2 is arranged in protected coal seam release scope; being ribbon by the pumping and mining pressure relief radius at the bottom of the hole evenly arranges; pumping and mining pressure relief radius at the pit coal layer is 15~20m; be provided with that spacing is 15-20m at the bottom of the hole, this bore arrangement mode helps tackling the gas pressure relief of protected seam.
To the construction of layer-through drilling 2, can adopt the high-pressure blast deslagging to creep into for down, blast is 7-9Mpa.Because the down-hole high pressure air duct pressure does not reach this requirement, therefore, need the special mobile air compressor of settling.