SU1693264A1 - Method of drainage of satellite seams - Google Patents

Abstract

The invention relates to mining and m. used for the degassing of satellite satellites (PS) and contiguous layers during the development of a suite of gently sloping layers with an objective-free system for preparing excavation pillars. The goal is to increase the efficiency of degassing of the substation by increasing the life of the wells with the intensification of gas release. The first part of the degassing well DS is drilled in the PS ahead of the clearing slab from the production of the adjacent excavation column to the border of the displacement of the roof rocks of the excavation column. The second part of the DW is conducted along the SS to the boundary of the collapse of the roof rocks. The transition from the first part of the DS to the second part is carried out by preliminary execution of a germinal crack from the bottom of the first part of the DS, followed by washing out the cavity of the second part of the DS. Elution of the cavity is carried out by supplying liquids through a high-pressure pipeline (TP). At the same time, a degassing TP is periodically connected to the DC to remove stub, liquid and gas. After the cavity has been created, before the approach of the clearing slab, the coal and rock mass is fractured and the proppant is pumped into the DW. After the passage of the clearing face of the DS section, a repeated hydraulic fracturing is performed and the methane is continued to be collected from the mined-out area. When the PS is located in the soil of the reservoir under development, one part of the DS is drilled in the rear section to the border of the soil rock unloading, and the other part of the DS is performed along the PS to the border of the soil rock discharge of the developed column. 1 з п. Ф-лы, 12 ил СО с о о со N) sk Ј

Description

The invention relates to mining and can be used for the degassing of satellite beds and contiguous layers when working on a suite of gently sloping coal seams with an objective-free system for preparing mining pillars.

The aim of the invention is to increase the efficiency of degassing of satellite formations by increasing the lifetime of the wells during the intensification of gas evolution.

Fig. 1 shows the layout of the coal seam being developed and the satellite formation above it in the mountain massif; the vertical section in Fig. 2 is section A-A in Fig. 1; in Fig. 4, section B-B in Fig. one

figure 4 is a section bb In figure 1; Fig. 5 illustrates the placement in the well of a drilling composition with a creamer at the moment of cutting the germinal gap; 6 shows placement in the well of equipment for hydraraying rocks after cutting the germinal gap; Fig. 7 shows the layout of the process equipment in the excavation drift for fracturing and gas suction; Fig, 8 - section GGD of Fig.7; figure 9

- a diagram of the joint arrangement of satellite layers above and below the developed coal seam in the mountain massif is presented; figure 10 is a section dD in figure 9; figure 11 - section EE of figure 9; on Fig

-F-section in Fig.9.

The satellite layer 1 is degassed during the process of lifting the cleaning hole 2 between the conveyor drift 3 and the ventilation drift 4, passed along the coal seam 5 under development and forming the extraction pole 6. The adjacent extraction pole 7 is contoured with the drift 8 (Figures 1 and 2).

Above the coal seam 5 in front of the clearing hole 2 there is a zone 9 of geostatic stresses, a zone 10 of the reference rock pressure, and above the undermined satellite 1, there is a zone 11 influenced by the supporting rock pressure from the mining excavation column 6. Behind the clearing slab 2 in soil rocks 12 The coal seam 5 has a discharge zone 13, and in the roof rocks 14 there is a zone 15 of collapse, a zone 16 of cracks and a zone 17 of the curvature of the roof rocks. Behind the discharge zone 13, a pressure increase zone 18 is located with a transition to the zone 19 of the recovered stresses.

In the drawings, the first part 20 of the well is drilled, drilled from the drift 8 of the adjacent excavation column 7 towards the reservoir uprising 5, the boundary 21 of displacement of the roof rocks 14 of the excavation pole 6 being processed with the adjacent extraction column 7, the transition zone 22 is located at the contact 23 of the roof rocks 14 with the reservoir -satellite 1 and at the same time on the border 21 of displacement of the roof rocks 14 of the excavation column 6 being worked out, the second part 24 of the well, located at the contact 23 of the roof rocks 14 with the satellite-companion 1, the drilling became 25, the explorer 26, embryonic thre ina 27, packer 28 with a set of sealing rings 29, high-pressure pipeline 30, mouth 31 of the first part 20 of the well, high-pressure pump 32, tank 33 with propping material, mixer 34, shut-off valve 35 of high-pressure pipeline 30, degassing pipe 36. slurry separator 37, water separator 38, shut-off valve 39 of the degassing pipeline 36, low-pressure pipeline 40, pressure gauge 41, boundary 42 of the caving of Roofs 14, dividing the excavation work

pillar 6 and previously spent extraction column 43, fractures of the bundles around the first part 20 of the well, zone 45 of increased fracturing and the space 46 of the excavation column 6.

0 The method is carried out as follows.

In front of the clearing slab 2 outside the zone 10 of the reference rock pressure in the rock of the roof 14, the first part 20 of the well is drilled from the drift 8 of the adjacent excavation column 7 towards the rising of the coal seam 5 to the border 21 of displacement of the roof rocks 14 of the excavation column 6. The bottom of the first part 20 of the well located on this border, i.e. in the pillar

0 and up to the contact of 23 roof rocks 14 with the satellite 1.

Then proceed to the implementation of the second part 24 of the well. To do this, the first part 20 of the well is drilled to become 25

5 with a slicer 26, with which a germinal crack 27 is cut from the bottom of the first part 20 of the well to the side of the coal bed 5 rising up at the contact 23 with the satellite layer 1. After cutting the breathing crack 27, the drill rod 25 with the slot generator 26 is removed from the first part 20 wells. Below the germinal-crack 27 in the first part 20 of the well, a packer 28 is installed with a set of sealing rings 29, which pass through the high-pressure pipeline 30.

The mouth 31 of the first part 20 of the well is cased, cemented and connected to it is a high-pressure pipeline 30 with a single-head pump 32 with a capacity of 33 seconds

propping material

34 and degassing pipe 36 with a sludge separator 37 and a water separator 38.

The second part 24 of the well is made

5 from the germinal crack 27 by washing out the cavity in the satellite 1 by supplying fluid under high pressure and quickly dumping it. The cavity of the second part 24 wells create directed from zone 22

0 transition, i.e. on the bedding on the contact 23 of the roof rocks 14 with the satellite layer 1, orienting it parallel to the main endocoupling system of the mountain massif to the border 42 of the roof rocks collapse 14.

5 A sharp discharge of the working fluid is accompanied by intensive removal of the coal stub of the satellite-1 formation through the first part 20 of the well and then through the degassing pipeline 36 to the sludge separator 37 and the water separator 38 to form the washed

cavities. Repeatedly increasing and dramatically depressurizing further elution of the cavity occurs, as a result of which a second part 24 of the well is formed. The injection and discharge of the working fluid is performed by opening and closing the shut-off valve 35 of the high-pressure pipeline 30, while the shut-off valve 39 of the degassing pipeline 36 is in the closed position; At the end of the injection and discharge cycles, the shut-off valve 39 is opened. A degassing pipe 36 is connected, through which the stub, water and gas are removed.

Since after the discharge of the fluid under the action of rock pressure, the washed cavity closes, then to preserve its open ™ and to create splitting cracks 44, the carbon formation is fractured.

Hydraulic fracturing of the coal massif is carried out as the refining bottom 2 moves to the first part 20 of the well and makes it between the displacement boundary 21 and the opposite edge 42 of the roof collapse 14 above the extraction column 6..

The fracture of the coal massif is carried out with the shutoff valve 35 of the high-pressure pipeline 30 open and the shut-off valve 39 closed on the degassing pipeline 36, which prevents the working fluid from entering the degassing pipeline 36 when injected.

Hydraulic fracturing of the coal mass array with the formation of cracks 44 stratifications is accompanied by increased gas emission from satellite 1. At the moment gas enters the first part 20 of the well, the latter is connected to the degassing pipeline 36. opening a stop valve 39 for capturing gas from the gas-filled cracks 44 stratifications and cavities of the second part 24 wells. When gas suction stop valve 35 high-pressure pipeline 30 is closed. At the next abrupt discharge of the working fluid and gas coming from the cavities, the coal-bearing sludge from the fractures 44 of the bundles and the cavity of the second part 24 of the well is further washed out with the help of the working fluid. Coal sludge is transported through a degassing pipe 36 to the sludge separator 37, and the working fluid is respectively to the water separator 38, the gas is transported further along the pipeline,

As the sludge separator 37 becomes clogged, it is periodically cleaned of the sludge, and the working fluid from the water separator 38 is discharged into the drainage channel. The order of opening and closing the shut-off valves 35 and 39 is similar to that described above.

As far as the clearing of the slaughter surface 2.

5 when the cavity of the second part 24 of the well is in the zone 10 of the reference rock pressure, projection material is injected into it, which prevents the second part of the cavity from closing (closing)

0 24 wells. The proppant is fed into the well through a high-pressure pipeline 30 by means of a high-pressure pump 32 from the tank 33 through the mixer 34. The injection of the proppant

5 of the material produced by the known technology of fracturing coal seams, having previously shut off the shut-off valve 39 of the degassing pipeline 36. After the cracks and cavity have been fixed with an elimination material, the well is switched to gas drainage by closing the shut-off valve 35 of the high-pressure pipeline 30 and opening the shut-off valve 39 of the degassing pipe 5 36. The capturing of the released gas continues to continue even after the passage by the cleaning face 2 of the second section 24 of the well, i.e. when its second part 24 remains in the worked-out space 46 of the excavation column 6.

As the clearing inlet 2 continues to move, the gas release rate from the second part 24 of the well in the discharge zones 13 and increasing stresses

5 18 decreases due to compaction of roof rocks 14 and a decrease in their gas permeability. In zone 19 of the recovered stresses, the intensity of gas release decreases to the level of gas release of rocks.

0 occurring in the natural state of the array. Therefore, in order to increase gas release beyond the discharge zone 13, a re-fracturing of the enclosing roof rocks 14 of the second part 24 of the well 5 across the width of the excavation column 6 being worked out between the boundaries of the displacement 21 and the collapse of the 42 roofs of the roof 14 is performed.

0 high-pressure pipeline 30, pre-closing the stop valve 39 degassing pipeline 36 and opening the stop valve 35 high-pressure pipeline 30.

5 As a result of re-fracturing in the area of the bottom of the second part 24 of the well, in the rocks of the roof 14, zones 45 of increased fracturing are formed. Re-hydraulic fracturing intensifies the process of gassing not only of Satellite 1,

but also of the excavated space 46 of the excavation column 6 due to the re-opening of the cracks 44 of the bundles and communication of the zones 45 of the increased fracturing with the systems of cracks 16 and 17 of the roof rocks 14 in the region of the displacement border 21 below the formation 1 satellite. This allows maintaining the gas release rate at a high level until the end of mining the extraction pole 6.

Re-fracturing is carried out until a sharp steady drop in pressure of the working fluid occurs and the impossibility of raising the pressure to the required values. After re-fracturing, the working fluid is discharged from the well and gas is drained.

Further technological operations on the degassing of the satellite bed 1 through other wells are carried out in a similar order as the refining slab 2 is pushed up to the end of mining of the extraction column 6.

The drilling of the first part 20 of the well is carried out in the pillar by drilling machines up to the border 21 of displacing roof rocks 14. Water with the addition of chemically active substances is used as a working fluid during hydraulic fracturing and leaching, and as a proppant for securing the second parts 24. wells use sand. The high-pressure equipment (pump, mixer, reservoir with proppant material) is transferred from one well to another as the cleaning hole moves. Wells equip degassing devices for capturing gas. The high-pressure pipe is plugged with a shut-off valve.

With a joint arrangement of satellite layers above and below the layer 5 under development, the degassing of the lower satellite layer 47 is also performed. as well as a plast-companion, 1. From generation 8 adjacent to column 7 in front of the clearing slab 2 outside zone 10 of reference rock pressure, soil rocks 12 drill first part 48 of the well towards reservoir 5 up to border 49 unloading soil rocks 12 excavation column 6 The bottom 50 of the first part 48 of the well is located at this boundary, i.e. in the pillar, on the contact 51 of the soil rock 12 with the satellite layer 47. Over the satellite bed 47 under development, as well as above the satellite bed 1, there is a zone of increased rock pressure resulting from the influence of the reference rock pressure developed layer 5 in the process of its development.

The creation of the second parts of the 53 wells located above working on

the satellite layer 47 under the workout extraction column 6 is carried out in the described manner and using the same equipment.

In the bottom 50 of the first part of the 48 well

using the slider 26, on the contact 51 of the soil rocks 12 with the satellite layer 47, a germinal crack similar to the germinal crack 27 is cut, from which the second part 53 of the well is washed out of the cavities in the plastic satellite 47. Additional fractures 54 of the delamination around the bottom 50 of the first part 48 of the well are created by hydraulic fracturing of the carbon-rock mass between

boundaries 49 and 55 unloading of soil rocks 12 under the excavation column 6. Re-fracturing is carried out in zone 13 unloading with formation in soil rocks 12 zones 56 of increased fracturing located above the working bed of satellite 47 between the boundaries 49 and 55 of soil rock unloading 12 of the excavation column 6,

The gas drawn during the washing out of the cavities and the production of hydraulic fracturing before and after clearing the borehole 2 of the section of the second part 53 of the well is carried out in the same way as the gas was dragged through the satellite 1. All of the well procedures are followed.

the end of the mining excavation column 6.

Example. The outgassing of the reservoir satellite, located above the developed reservoir at a distance of 25 m, is carried out.

The method of preparation of the developed

layer - horizontally, the development system - long columns along the strike. The length of the lavas or the width of the excavation pillars along this stratum is 250 m. The depth of mining operations is 750 m. Rock strength

Coils between 70–90 MPa. The strength of the coal seam satellite compressed 10-20 MPa. In-situ gas pressure of the satellite 4 MPa.

0In the period of preparation of the adjacent excavation column 7, from the conducted drift 8 in the rock of the roof 14, the first part 20 of the well is drilled in the direction of the excavation column 6 to be drilled to the displacement borders 21

5 roofs 14. The boundary of 21 displacements is calculated according to the formula (70 ° -0.6 a), where a is the angle of incidence. According to the calculations, near 0 displacement boundary 21 is calculated at an angle of 70 ° to the horizon.

The bottom of the first part 20 of the well is located at the boundary 21 of displacement of the rocks of the roof 14 and at the same time near its contact 23 with the soil of the satellite formation. The first part 20 of the well is made with a standard SBG-1 type drilling machine with a 93 mm projectile diameter.

After the creation of the first part 20 of the borehole, the rig 25 is equipped with a selector 26 and injected into the borehole to create a germinal crack 27, the depth of which must be at least half the borehole diameter and 0.6–0.7 m long. germ cracks 27 along the length of the first part 20 of the well are monitored according to geological exploration data, for example, from pre-drilled wells with a core.

After removing the drill rod 25 from the well with the slotter 26, a packer 28 with a set of sealing rings 29 is introduced into the well. Packer 28 is installed below the germinal crack 27 and proceeds to the second part 24 of the well.

 The second part 24 of the well is eluted using a hydroimpulse effect on the massif by injecting the working fluid through the first part 20 of the well under a pressure equal to the geostatic, yi, followed by abrupt discharge to the hydrostatic level.

The cavity of the second part 24 of the well is formed by the following process. When the working fluid is injected into the satellite 1, the stress state of the coal due to the geostatic stress and the in-situ gas pressure is increased as a result of the high-pressure injection of the working fluid. With a sharp depressurization, a discharge wave arises, which, together with the energy reserves of gas and elastic deformations, is realized in the destruction of the coal. As a result of the destruction of coal, a cavity is formed and the destroyed coal under the velocity pressure of water and gas is released through the well in the form of pulp.

The injection and discharge process is repeated many times until a second part 24 of the well is formed.

In order to perform the second part 24 of the well, equipment and pumps are used to inject fluid into the mountain range.

When implementing the method for performing the second part 24 of the well, as well as for fracturing, use of high-pressure pumps of type 2 UGN with a capacity of 94 l / min and a maximum pressure of 40

MPa. Water with the addition of surfactant D010 with a concentration of 0.06-0.1% is used as a working fluid.

To install the second part 24 of the well, after installing the packer 28, the working fluid under pressure of 19 MPa is supplied through the high-pressure pipeline 30 to the embryonic treChen 27, after stabilizing it in the well, a sharp pressure is released to 7.5 MPa and the broken coal in the form of pulp and gas is thrown out through the first part of the well 20.

The process of injection, discharge, removal of pulp and gas is repeated many times and is completed after stabilization of the pressure in the well below the level of gas pressure in the area of 4 MPa, which means that the second part 24 of the well leaves the depleted space 46 of the previously spent extraction column, i.e. it is made to the full, up to the border 42 of the collapse of the roof rocks 14, the spatial position of which is given by an angle of 53 °. The distance between the wells is 80-100 m.

After creating the second part 24 of the well and flushing the fluid, the proppant material is fractured and injected to maintain the openness of the cavity and create fractures 44.

The fluid injection pressure during hydraulic fracturing is determined by the formula

Р 0,25Н- Рпл + Ор. 0.25x750-4.0 + 2 16 MPa, where Rpl is the gas pressure in the reservoir, MPa.

Op is the tensile strength of coal, MPa;

H - depth of maintenance of work, m.

Quartz sand with a particle size of 0.5-1.0 mm is used as a proppant.

Re-fracturing is performed as the striker 2 moves toward the first part 20 of the well. The necessity and frequency of hydraulic fracturing of the coal-bearing massif is determined on the basis of monitoring the gas pressure and the amount of gas being absorbed from the reservoir satellite 1 and its host rocks.

Claims (2)

1. A method of degassing satellite formations, including drilling wells ahead of a clearing hole in the satellite formation area, casing, cementation and sealing of wells, connecting wells to a degassing pipeline and gas suction, characterized in that, in order to increase the efficiency of degassing satellite formations by increasing the life of the wells during the intensification of gas evolution, a part of the well is drilled in the pillar from the production of the adjacent excavation column to the displacement boundary of the rocks of the excavation column being worked, and The part of the well is made along the satellite formation, along its contacts with the soil, to the boundary of the rock breakdown, which separates previously worked out and excavation poles, while passing from one part of the well and the other is accomplished by preliminarily performing a germinal crack with a slot generator from the bottom of the well, drilled in the rear sight, then the starter is removed, connect this I Li. five the part of the well to the stand, which serves the fluid under high pressure and flushes out the cavity of the part of the well located along the satellite formation. 2. The method according to claim 1, characterized in that when the satellite bed is located in the soil of the reservoir under development, an additional well is drilled, while a part of the well is drilled in the pillar to the boundary of the soil rock unloading, and the other part of the well goes in the direction of the bed -satellite, and the end of this part is located on the opposite border of the soil rock unloading developed mining station. 1ShShSh.SHGGPP -13 . 18 -12 item FIG. i A-1 22 bpzf I t 2 43 B - B FIG. four FIG. five / Wu HK : / Sh-45 ///. 45 %  / 7 FIG. 6 CO O S-00 CO CO INVch (About see with (ABOUT 00 & with (ABOUT g S: -6 fr92E69t “IG. ten . II , 0-JIU, 0-1 /four 12 55 / 7 K-B 5053