SU1652614A1 - Method for fighting gas-dynamic phenomena in mining coal seams - Google Patents

Abstract

The invention relates to mining promet and m. B. used in the development of coal seams, hazardous on mountain snowstorms and sudden coal outcrops, having satellite beds and characterized by hard-to-damage roofs and strong soil. The purpose of the invention is to improve the safety and efficiency of operations by ensuring the uniform deformation of the coal seam and the formation of spikes with immediate soil. Ahead of the clearing slab behind the support pressure zone, under the coal seam, a softened layer (PC) is created in the immediate soil (NP) of the calculated value equal to 0.2-0.4 of the length of the protected zone. For this, a well is drilled (C) before the NP rocks contact the reservoir under development. C is planted to the lower boundary of PC and cemented at this boundary; charges of explosives are placed on the contact of NP rocks. High-pressure PC humidification is produced at C drilled from the side of the unworked coal mass. The alternation of cycles of high-pressure humidification, discharge of liquid and gas suction is carried out at C drilled from the side of the spent single or paired lavas of the excavation column. Begin the alternation with liquid discharge, end with high-pressure humidification through two C, which are carried out simultaneously at least through the length of the high-pressure humidification zone and the cycle alternation time is determined depending on the number C, their diameter, influence radius, length of the filtering part C, pump performance and relative frequency of endocouping NP. High-pressure moistening, discharge of liquid and gas suction are completed before the cleaning face of the faces C for an amount not less than half the pitch of the secondary precipitation of the main roof. When working with paired lavas, the alternation of cycles is performed simultaneously along C from the side of the adjacent paired excavation column and from the side of the unworked coal seam. 2 h. the item of f-ly, 8 ill. C Ј (L O5 ate 1C o

Description

The invention relates to the mining industry and can be used in the development of coal seams, hazardous from rock bursts and sudden emissions of gas and gas, having satellite formations and characterized by hard-to-damage roofs and strong soil.

The purpose of the invention is to improve the safety and efficiency of the work by ensuring the uniform nature of the coal bed deformation and disturbance of the adhesion of the reservoir to the immediate soil.

FIG. 1 shows a preparation scheme and a coal seam development system;

on FSH 2 —L-A cross section on FSH I, FIG. 3 BB section on FSh 2, FIG. 4 drilling pattern for the elongation of soil deformations in the protective zone, FIG. 5 — connection diagram of wells with light and high-level stanchions ; FIG. 6 is a diagram of the preparation of the m coalbed development system using paired lavas; FIG. 7 is a section R-B of FIG. 6; FIG. 8 is a diagram of well overlaying in the development of a single impact coal seam.

In one of the embodiments of the method, the extraction column I is prepared by holding the conveyor tunnel 2 parallel to the ventilation drift 3, and then worked by the cleaning face 4 A zone of the maximum pressure reference 5, a zone of influence of the reference pressure 6, weakening layer is located ahead of the cleaning hole 4 -7 direct soil 8, contact 9 of the de-strengthable layer 7 of direct soil 8 with a coal seam 10, and behind the clearing hole 4 - an elastic displacement zone 11 of direct soil 8 located in the discharge zone 12 of the spanning space 13. The diagram shows the cementation boundary 14, the zone of geostatic stresses Y 15- wells 1C, coal companion satellites 17, charges BB 18, main roof 19, line 20 dispositions of explosives, cracks 21 in the softened direct soil layer 7 7, respectively, ventilation and conveyor drifts 22 and 23 on a contiguous formation 24, degassing becoming 25, water separator 26, high-pressure becoming 27, downhole 28 of the well, protection zone 29, high-pressure pump 30, pressure gauge 31, unworked coal array 32 , spent excavation hundred forehead 33, shut-off valve 34 of the high-pressure rod 27; shut-off valve 35 of the degassing valve 25; the second practiced extraction column 36, excavation drifts 37 and 38 of the developed and contiguous coal beds 10 and 24; the unworked coal massif 39, which borders on the second worked out extraction column; BUT - low-pressure pipeline; mechanized complex 41 in the downhole 4; strain gauge 42, measuring well 43.

The method of combating gas-dynamic phenomena is carried out as follows.

From the conveyor drift 23 and the ventilation drift 22 of the contiguous reservoir 24, as the striking hole 4 (fig. I-3) moves in the zone of geostatically stresses 15, drills the borehole 16 to contact 9 of the defrosting layer 7 of the direct soil 8 with the coal seam 10 The wells 16 live up to the boundary 14, which is the lower boundary of the softening layer 7 of the direct soil 8, is cemented at

and then charged with charges 18, positioning them at the contact 9 of the weakening layer 7 of the immediate soil 8 with coal coal 10 but line 20. parallel to the cleaning

Bottom 4 Charges 18 explode before approaching them to the zone of influence of the reference pressure 6 In the protective zone 29, where the coal seam 10 loses its bearing capacity, and its direct soil 8 overtakes from the three axial state to the biaxial one and becomes uniaxial, the rise of direct soil 8 under coal seam 10 and whether its elastic recovery, according to the indications of deep genodeformams 42, occurs from a critical depth h, which corresponds to the strength of weakening e-motor layer 7, determined by the ratio

/ i (0.2-0.4) / j. m

where /. width of the protective zone 24 of coal seam 10, m The numerical value of h is measured

° but elastic recovery of soil rocks 8 in the protection zone 29. The research problem was solved by installing depth strain gauges 42 but the length of the measurement well 43 drilled in the rock

5 of soil 8 according to the scheme (FIG. 4), the readings of the deep binometric strain gauge deformers 42 were taken with the aid of the strain gauge IID-3. The measurement accuracy was 0.001 mm. The magnitude of the elastic deformations in the protective zone 29 decreases with distance from

0 coal seam 10 in soil rock 8 and stabilized at a depth of 0.2 /. and 0.4 / .. respectively before and after the secondary precipitation of the main roof 19.

The distance between the wells 16 along the extraction column 1 and along the length of the clearing

5 and 4 is determined by ensuring that the direct soil 8 is evenly destroyed and 21 cracks 21 are formed in it, both parallel and perpendicular to the bedding of the rocks.

0 Charges 18 explode in the zone of geostatic stresses 15. After blasting charges 18 wells 16, drilled from the conveyor drift 23 and the ventilation drift 22, are connected to the degassing station 25 and begin to degas the reservoir 10 and the rocks of the immediate soil 8 and coal seams of satellites 17. Desorption or transition of methane gas from molecular to free state in the reference pressure zone 6 of

The developed coal bed 10 and the coal-bearing massif are caused by the displacement of the rocks of the direct soil 8 and the satellite beds 17 in the explosive charge 18, the creation of an unstable layer 7 of a given thickness, characterized by increased technological disturbance and gas permeability. The cracks 21 are oriented perpendicularly and bedding, serve in

layer 7 with gas-conducting channels for suction gas through wells 16.

As the distance between the downhole 4 and the nearest in front of the well 16 used for gas suction is reduced, the stress state of the mountain massif increases, which gradually leads to the closure of cracks 21, reducing the gas permeability to a minimum. When the pressure of methane gas and in the wells of 16 to 1 MPa drops, the second stage is started — high-pressure wetting of the softened strength layer 7 of the direct soil 8 from the side of the unworked coal mass 32 and alternating high-pressure wetting cycles of the direct soil 8 and discharge of liquid and gas suction through the wells 16 - from the side of the spent extraction column 33.

High-pressure moistening from the side of the unworked coal massif 32 and alternating cycles of high-pressure humidification and discharge of liquid and gas suction through wells 16 from the side of spent extraction column 33 is carried out through at least two adjacent wells 16. This condition is determined by the zone of high-pressure moistening whose feminity is determined by

/ (0.3-0.5) n-D, where p is the number of wells in the support zone:

D is the diameter of the wells.

The length of the high-pressure humidification zone was determined by the appearance of fluid in the refining face 4 or by seepage into the refining face 4 due to a violation of the commissure at the contact 9 between the coal seam 10 and the weakened layer 7 of the soil rocks 8. Highly wetted through the wells 16, the number which, while simultaneously injecting fluid into them, varied from one to five.

To implement high-pressure humidification of the well 16, drilled from the conveyor drift 23, is disconnected from the degassing rod 25 and connected to the high-pressure pump 30 through the high-pressure stabilizer 27. The wells 16, drilled from the ventilation drift 22, are additionally connected to the high-pressure pump 30 through a high pressure stand 27. In this case, a water separator 26 is connected to the degassing stand 25 on the ventilation drift 22.

Thus, high-pressure humidification is carried out from the conveyor drift 23 through the wells 16, and high-pressure humidification and liquid discharge and gas suction cycles alternate from the ventilation drift 22. The water separator 26 serves to separate the discharged fluid through the wells 16 from the gas-air mixture entering the degassing station 25. Regulation

ten

15

20

25

thirty

35

40

45

50

55

cycles are performed by opening and closing the shut-off valves 34 and 35 (Fig. 5). The stop valve 35 of the degassing rod 25 is closed before the high-pressure humidification, and the valve 34 of the high-pressure rod 27 opens. And vice versa. Before discharge of liquid and gas suction, the stop valve 34 is closed and the valve 35 is opened.

Under the action of high-pressure moistening, the strength properties of the softened strength layer 7 of the immediate soil 8 are further reduced, the cracks 21 are filled with liquid, which in this case works like hydrocline, they are spread apart, and additional cracks 21 form in the maximum pressure-bearing zone 5, which causes the bed 7 rocks of this region into a pseudoplastic state and ensures their uniform movement together with the formation 10 towards the developed space 13. Blasting charges 18 on contact 9 with a coal seam 10 violates its soldering with the direct soil 8, which also contributes to its independent movement towards the open space 13 across the width of the protection zone 29, and this pattern of movement of the coal seam 10 represents the deep pressing of the coal mass array and is accompanied by an offset from the bottom 4 to the depth of the array the zones of maximum of the reference pressure 5 and, consequently, an increase in the width of the protective young 29. The noted changes in the physicomechanical properties of the rocks of soil 8 exclude, therefore, synchronous oscillations containing rocks. The movement of the rocks of the weakening layer 7 together with the coal layer 10 towards the developed space 13 is also promoted by the influence of a high stress concentration ratio, which reaches 5-88N in shock-hazardous formations in the zone of the maximum reference pressure 5. This movement is also promoted by the direction towards the developed space 13 the pressure of the gas passing from the sorbed to the free state as a result of the cracking and displacement of rocks of the direct soil 8 and pushed aside by the front of the liquid from the zone of maximum reference pressure 5 in the direction of the open space 13 for suction through the wells 16

The choice of wells 16 drilled on the side of the waste extraction column 33 for gas suction in the case of a coal seam 10 with a single clearing face 4 (Fig. 8) is determined by the diffusion of gas processes occurring in the coal array. The diffusion is accompanied by the equalization of the gas pressure in the coal-bearing massif over the width of the extraction column 1 being worked out. The equalization of the gas pressure occurs in a direction from less than

loaded areas to rock-loaded areas 10

In the case of simultaneous mining of excavation pillars 1 and 36 (FIG. 6, 7), i.e., during the development of paired clearing faces 4, the alternation of high-pressure wetting cycles of direct soil 8 and discharge of liquid and gas suction in relation to extraction column 1 is performed on wells 16 drilled from the ventilation drift 22 from the side of the spent excavation column 33, and in relation to the excavation pole 36, simultaneously in wells 16 drilled from the drifts 23 and 38, i.e. from the adjacent paired excavation pole 1 and from the side of the unworked coal massif 39 In the latter case, the double-sided buildup of the coal-rock massif is due to the fact that excavation column 36 is in a relatively uniform stress state in comparison with excavation column 1, which is adjacent to the exhausted extraction column 33

High-pressure moistening from the side of the unworked coal massif 32 (Figures 1, 2, 3, 7) and the alternation of high-pressure moistening and liquid discharge and gas suction through the wells 16 from the waste extraction column 33 is carried out through no less than two adjacent wells 16

The frequency of alternating cycles of high-pressure moistening of the softened layer 7 of the immediate soil 8 and the discharge of liquid and gas suction is established experimentally. The frequency of alternation of these operations is determined by the formula

/

/ 2-l- / lt

-, min,

where R is the average radius of the influence of wells 16, m,

(f is the length of the filtering part of the wells 16, m,

d - pump capacity 30 of high-pressure humidification, m3 / min, t - relative frequency of cracks in the encapsulation of direct soil 8, coming from 1 m, is equal to 0.5-0.7 when the wells work in the protection zone 29 and t 1 - beyond the zone of maximum reference pressure 5

The alternation of high-pressure humidification and discharge of liquid and gas suction is carried out in mining shifts, i.e. when coal is dredged in a clearing bottom 4, and a series of alternations of cycles are completed by overlapping wells 16 after the end of the next cycle of high-pressure wetting of the immediate soil 8 Wells 16 overlap at the end of the mining shift before the start of the repair, even after the end of the coal excavation. Begin a series of alternations of cycles after the end of the repair shift, that is, after

the beginning of the new mining shift, and starting with the operation of the discharge of liquid and suction

After the transition of the downhole 4 of the 28 wells 16 by an amount not less than half the pitch of the secondary roof of the main roof 19, the operation of the high-pressure wetting of the softened soil 7 of the immediate soil 8 is stopped, and the wells 16 drilled both from the side of the unworked coal mass 32 and the spent excavation column 33 is connected to a degassing station 25 for sucking gas

, - The third application of this method of dealing with dynamic phenomena is presented in the conditions of mining the coal seam 10 by paired lavas (Fig. 6, 7). The injection of fluid into the wells 16 is carried out with a high-pressure pump.

0 UGN-30, and Pressure is controlled by a pressure gauge 31 Wells 16 are drilled using the SBG-1M drilling machine, and are loaded with explosive cartridges of type No. 6-ЖВ or T 19, placing the cartridges into torpedoes with a length of 3 m

5 separate torpedoes between each other in a monozar d, sending a monozar into the well is carried out according to the known technology of hydromotorpedimentation. The cycle of preventive work in this method is 15-20 m along the seam of the formation

o For one cycle of soil treatment within the excavation column, 72 kg are consumed. High-pressure humidification is carried out with the aid of UGN pumps, which are installed on the conveyor belt and vent track 23 and 22, connected to the well 5 to us 16

The second application of this technical solution is presented in FIG. 8. The wells 16 in this case are drilled near the coal seam 10 directly from the workings 2 and 3, which were covered by coal

0 layer 10

Claims (3)

Invention Formula 1 A method of combating gas-dynamic effects in the development of coal seams, including determining the length of the reference pressure zone, drilling wells ahead of the bottom zone of the reference pressure in the mountain range from the side of the unworked coal massif and the spent excavation column to the zone of direct soil rocks with the reservoir under development, determination of the parameters of fluid injection into the wells and the wetting radius, casing and cementation of the wells, placement of charges of explosives 5 in the wells, and vanie softening layer of blasting charges to approach the reference pressure zone, connection to the high-pressure wells and puts degassing, high-pressure moisturizing liquid discharge cycles gazochereduyuschimis on wells prior to stabilize the gas pressure on the wells, degassing the rock mass, characterized in that. to improve the safety and efficiency of operations by ensuring the uniform nature of the coal seam deformation and disturbance of the spike-to-soil spike, preliminary determine the step of secondary sedimentation of the immediate roof, the width of the protective zone of the developed seam and the direct soil end-pouring cracks and charges of explosives placed on the contact of the rocks of the immediate soil with the reservoir under development, and the wells are planted to the lower boundary of the weakened The direct soil layer is cemented at this boundary, while the high-pressure wetting of the weakened direct soil layer is carried out on wells drilled from the unworked coal massif, and the alternation of high-pressure wetting cycles, liquid discharge and gas suction is produced on wells drilled from spent excavation layer, and begin the alternation of cycles with fluid discharge and gas suction, and finish with high-pressure moistening, while the power of the weakened About the layer of direct soil, the length of the zone of high-pressure moistening and the time of alternation of cycles are determined respectively by the formulas .2 -0 ,,, .3-0,5i-n), 0 five 0 t R2-n-l + -m q where h is the power weakened about a layer. /, is the width of the young paipafia formation; n is the number of wells in the reference zone. / - the extent of the high-pressure humidification zone; D is the diameter of the wells; / - cycle rotation time; / is the average radius of the influence of the wells, / F - the length of the filtering part of the wells. q - pump performance; m is the relative frequency of endoconviation of direct soil. 2. A method according to claim 1, characterized in that high-pressure humidification is carried out simultaneously through at least two wells, the high-pressure humidification of the softened layer and the alternation of high-pressure wetting cycles, liquid discharge and gas suction end up to the transition of the bottom hole wells of at least half of the pitch of the secondary precipitation of the main roof, and after this transition only gas is sucked 3. The method according to claim 1, characterized in that the alternation of cycles of high-pressure moistening, discharge of liquid and suction of the reservoir during the coal seam development system with paired lavas is performed simultaneously through wells drilled from the adjacent paired excavation column and from the side of the uyulno array 25 W 33 22 - ..- 1 L, r-k --- 4- FIG. one Ua 33 27 25 Fig 2 5-5 i}) i} mimiiiiii iii / i ///////////////////////////////////////// //, FIG. 3 B gpf l + i And 92991 W 22 33 25 76 6 in-in / / 30 22 / , e 75 v 2k & /////////////////// At ///// hG 27 fO 7 J $ -36 AT nineteen 27 38 30 W ; x gtt-y  21 iff 7 18 16 77 8 U 27 3D W 2 32 Fig 8