CN110939442A - Method for treating rock burst by pressure relief source in ground fracturing area - Google Patents
Method for treating rock burst by pressure relief source in ground fracturing area Download PDFInfo
- Publication number
- CN110939442A CN110939442A CN201911276023.4A CN201911276023A CN110939442A CN 110939442 A CN110939442 A CN 110939442A CN 201911276023 A CN201911276023 A CN 201911276023A CN 110939442 A CN110939442 A CN 110939442A
- Authority
- CN
- China
- Prior art keywords
- well
- fracturing
- rock
- rock stratum
- horizontal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal
Abstract
The invention provides a method for treating rock burst by a pressure relief source in a ground fracturing area, which comprises the steps of determining a target rock stratum needing to be modified and relieved in an area with hidden danger of the rock burst; determining a well arrangement mode of a fractured well in the target rock stratum, and drilling the well; the fracturing well comprises a horizontal well or a vertical well; and performing directional fracturing on the fractured well after drilling. The method for treating rock burst at the pressure relief source of the ground fracturing area can obviously reduce the stress concentration degree during coal seam mining, enables the coal body stress to be always under the critical stress generated by the rock burst, fundamentally eliminates the serious hidden danger of the rock burst caused by the sudden fracture of a large-area top plate, belongs to strategic treatment measures of the rock burst, has important significance on the improvement of the rock burst prevention and control technology and concept in China, and has obvious social and economic benefits.
Description
Technical Field
The invention relates to the technical field of coal mine safety mining, in particular to a method for governing rock burst at a pressure relief source in a ground fracturing area.
Background
According to statistics, more than 80% of rock burst accidents in China occur in coal seam roadways with thick-layer hard top plates in 2006-2018. Particularly, 50-100m thick-layer hard top plates are arranged above 60m of a coal seam in Shendong, Shaanxi and Huanglong bases in northwest of China. The region is an important strategic base of coal production and storage in China, and the currently proven reserves are about 4452 hundred million tons, which account for about 31 percent of the national proven reserves; by 2020, the yield of three big bases is estimated to be 13.2 hundred million tons, accounting for 33.8% of national coal production. The resource reserves and the exploitation intensity are the biggest regions in China. Due to the existence of the thick-layer hard roof, the area of the suspended roof is large in the mining process, so that local stress concentration is caused, sudden fracture of the suspended roof is more instantaneous release of strong dynamic load, so that a malignant rock burst accident caused by group death and group damage is easily caused, even the rock burst accident affects the ground surface, the ground surface is strongly vibrated, and great harm is caused. However, because the hard roof is far away from the coal seam, the thickness is large, the treatment difficulty is great, the investment cost is high, the pressure relief measures adopted at present, such as roof blasting and hydraulic fracturing, are all located in a roadway and a chamber under a coal mine, the construction site can only carry out local pre-fracturing on the low roof rock stratum within a small range, and for the high-position thick-layer hard roof, the method is difficult to realize large-range treatment, which is one of important reasons for causing frequent occurrence of rock burst accidents. Therefore, how to fundamentally eliminate the threat of serious rock burst disaster induced by sudden fracture of a thick-layer hard roof in the mining process is a strategic measure for controlling the rock burst under the condition and is also a problem to be solved urgently in the current coal mine safety production.
Disclosure of Invention
The invention aims to provide a method for treating rock burst by a pressure relief source in a ground fracturing area, so as to effectively reduce the overhung area and the coming pressure strength during the coal seam mining and fundamentally eliminate the hidden danger of serious rock burst during the mining of the lower coal seam.
In order to solve the technical problem, the invention provides a method for treating rock burst by a pressure relief source in a ground fracturing area, which comprises the following steps:
determining a target rock stratum needing modification and pressure relief in an area with the potential risk of rock burst;
determining a well arrangement mode of a fractured well in the target rock stratum, and drilling the well; the fracturing well comprises a horizontal well or a vertical well;
and performing directional fracturing on the fractured well after drilling.
Further, the method further comprises the step of determining a potential rock burst hazard region, wherein the step of determining the potential rock burst hazard region comprises the following steps: and determining the area with the potential impact ground hazard according to the actual conditions of the mine or the adjacent mine, wherein the actual conditions comprise the occurrence history of the impact ground pressure, the geological conditions of the mine and the current mining conditions.
Further, the step of determining the target rock stratum needing modified pressure relief in the area with the potential rock burst hazard comprises the following steps: and determining a target rock stratum needing modification and pressure relief by adopting a main control key layer for coal mining and a main control key layer analysis method for energy transfer response analysis or microseismic monitoring based on mine geological data above the rock burst hidden danger area.
Further, the analysis of the main control key layer and the energy transfer response of the coal mining comprises the following steps: calculating a plurality of pre-ground fractured rock layers with the fracturing performance by utilizing a key layer theory;
and judging whether the target rock stratum is a final ground fracturing target rock stratum or not according to the residual energy transferred to the working face coal seam from the plurality of pre-ground fracturing rock stratums.
Further, still include: determining remaining energy transferred to a face coal seam from the plurality of pre-surface fractured rock formations; the method specifically comprises the following steps:
and according to the plurality of pre-ground fractured rock layers, calculating the residual energy transferred to the coal bed of the working face by utilizing the rock layer released energy attenuation characteristics.
Further, the calculating the remaining energy transferred to the working face coal seam from the plurality of pre-surface fractured rock formations by using the rock formation released energy attenuation characteristics comprises:
performing bending energy calculation on the plurality of pre-ground fractured rock layers to obtain rock layer release energy of the plurality of pre-ground fractured rock layers;
and calculating the residual energy transmitted to the working face coal seam by the rock stratum release energy of the plurality of pre-ground fractured rock strata according to the rock stratum release energy of the plurality of pre-ground fractured rock strata.
Further, determining a surface fracturing target rock stratum according to the residual energy transferred to the working surface coal seam from the plurality of pre-surface fracturing rock strata comprises:
and determining the pre-ground fractured rock stratum with the maximum residual energy as a ground fractured target rock stratum by comparing the residual energy transferred to the working face coal seam by the plurality of pre-ground fractured rock strata.
Further, the analysis of the key layer of the main control by using microseismic monitoring comprises the following steps: acquiring microseismic events with different energy levels for representing the activity of the surrounding rock in the rock stratum;
analyzing and using the microseismic events with different energy levels to represent whether the activity of the surrounding rock mainly occurs in the roof rock stratum or not;
and if so, analyzing the distributed layer positions of the high-energy events on the roof rock stratum, and determining the layer positions of the high-energy events which occur in a concentrated mode as the ground fracturing target rock stratum.
Further, the analyzing of microseismic events according to the different energy levels to characterize whether the surrounding rock activity occurs primarily in the roof strata comprises:
analyzing the proportion of microseismic events or the energy of the top rock stratum, the coal bed and the bottom rock stratum;
and when the number of the microseismic events of the top plate rock stratum is greater than the number of the microseismic events of the bottom plate rock stratum and/or the number of the microseismic events of the coal bed, or the energy of the microseismic events of the top plate rock stratum is greater than the energy of the microseismic events of the bottom plate rock stratum and/or the microseismic events of the coal bed, determining that the activity of the surrounding rock is mainly generated in the top plate rock stratum.
Further, the analyzing the distributed horizons of the high-energy events in the roof rock stratum, and the determining the horizons occurring in the high-energy event set as the target rock stratum includes:
and according to the microseismic events monitored by the up-and-down combined microseisms and the monitored microseismic event energy level, projecting the maximum energy level event to the roof rock stratum, and determining the rock stratum with the maximum microseismic event occupation ratio of the maximum energy level in the roof rock stratum as a ground fracturing target rock stratum.
Further, the determining the layer position of the roof strata distribution, which is the layer position of the high-energy event set as the ground fracture target strata, further comprises:
when the maximum energy level occurrence quantity is not enough to determine the ground fracturing target rock stratum, continuously analyzing the secondary maximum energy level events to the rock stratum position where the large energy events can be determined to be concentrated, and determining the target rock stratum; the insufficient maximum energy level occurrence quantity is that the energy events have distribution in different lithologies, and the contrast difference of the distributed rock layers is small.
Further, the determining the well arrangement mode of the fractured wells in the target rock stratum comprises determining the types of the fractured wells according to the occurrence state of the target rock stratum; types of fracturing wells include horizontal wells and vertical wells; the occurrence state comprises length and thickness; and determining the well direction of the vertical well or the horizontal well.
Further, the determining of the well body direction of the vertical well or the horizontal well comprises that when the fracturing of the vertical well is determined, the well body of the vertical well is always kept in the vertical direction, the horizontal direction projection is located in the middle of the target rock stratum, and the vertical direction projection penetrates through the whole target rock stratum; when the fracturing of the horizontal well is determined, the well body of the horizontal well comprises a vertical section, an inclined section and a horizontal section, wherein the three sections of the well body are positioned on the same plane, the horizontal direction projection of the horizontal section should penetrate through a target rock stratum and should be consistent with the minimum horizontal main stress direction of the target rock stratum, and the vertical direction projection should be positioned in the middle of the target rock stratum; the direction of the vertical section is always kept in the vertical direction; the deflecting section is connected with the vertical section and the horizontal section; the direction of the minimum principal stress in the target rock stratum is perpendicular to the direction of the maximum horizontal principal stress; the direction of the maximum horizontal principal stress is the initial fracture orientation of the rock of the target formation at the time of hydraulic fracturing.
Further, the method also comprises the step of determining the minimum horizontal principal stress direction of the target rock stratum, and specifically comprises the following steps:
conveying hydraulic fracturing equipment into a target rock stratum, and sealing the upper end and the lower end of a fracturing section by using a packer;
injecting high-pressure liquid, pressurizing until the rock is cracked, and taking the initial cracking direction as the direction of the maximum horizontal principal stress;
and taking the direction vertical to the direction of the maximum horizontal principal stress as the direction of the minimum horizontal principal stress.
Further, the subjecting the fractured well to high pressure hydraulic directional fracturing comprises: perforating on the wall of a well, after perforating, setting the perforation section, injecting fracturing fluid into the perforation section along the fracturing pipeline, making the crack to the inside extension of rock stratum, accomplishing first fracturing, deblocking at last, removing the fracturing pipeline to other positions of treating the fracturing, repeatedly setting and fracturing to the fracturing construction of accomplishing a well.
Further, the step of performing high-pressure hydraulic directional fracturing on the fracturing well further comprises the step of repeating the high-pressure hydraulic directional fracturing procedure to complete fracturing construction of other wells after fracturing construction of one well is completed, so that mutually communicated net-shaped fractures are formed in the target rock stratum.
Furthermore, when a confined aquifer or a soft broken rock stratum is encountered in the drilling process, a casing is put to the bottom of the confined aquifer or the soft broken rock stratum, cement slurry is injected between the casing and a well wall, and the wall of the exposed rock stratum is reinforced.
Further, when the roadway is designed and constructed, the roadway with potential rock burst danger is arranged in an area close to the position right below the horizontal well, the trend of the roadway is kept parallel to the direction of the horizontal well, so that the roadway is in the most effective pressure relief protection range, and the roadway comprises a transportation crossheading, a return air crossheading and a return air crossheading.
Further, the target rock stratum is a rock stratum which mainly induces the rock burst and has a single-layer or multi-layer combined thickness of more than 20m and a distance of more than 50m from the rock burst hidden danger area.
The invention provides a method for treating rock burst by a pressure relief source in a ground fracturing area, which is characterized in that a target rock stratum needing to be modified and relieved is determined in an area with hidden danger of rock burst; determining a well arrangement mode of a fractured well in the target rock stratum, and drilling the well; the fracturing well comprises a horizontal well or a vertical well; the directional fracturing is carried out on the fracturing well after drilling, the underground large-range modification and pressure relief of a target roof can be realized, the mining stress environment of the coal seam with impact danger is fundamentally improved, the impact danger of the mining coal seam is obviously reduced or even completely eliminated, and the normal mining operation is not influenced.
Drawings
Fig. 1 is a flowchart of a method for treating rock burst at a pressure relief source in a ground fracture area according to an embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating a target rock formation selection in a method for treating rock burst at a pressure relief source in a surface fracture area according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a vertical well arrangement mode in the method for treating rock burst by a pressure relief source in a ground fracture area according to an embodiment of the present invention;
FIG. 4 is a schematic structural view of a vertical well in a method for treating rock burst at a pressure relief source in a ground fracture area according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a horizontal well arrangement mode in the method for treating rock burst by a pressure relief source in a ground fracture area according to the embodiment of the invention;
fig. 6 is a schematic structural view of a horizontal well in the method for treating rock burst by a pressure relief source in a ground fracture area according to the embodiment of the present invention;
FIG. 7 is a schematic diagram illustrating the staged fracturing effect of a vertical well in a method for treating rock burst at a pressure relief source in a ground fracturing area according to an embodiment of the present invention;
FIG. 8 is a schematic diagram illustrating the staged fracturing effect of a horizontal well in the method for treating rock burst by a pressure relief source in a ground fracturing area according to the embodiment of the invention;
fig. 9 is a schematic layout view of a dangerous impact roadway in a relief area in the method for treating rock burst by a pressure relief source in a ground fracture area according to the embodiment of the invention;
fig. 10 is a schematic diagram illustrating an influence of a roof not weakened in a method for treating rock burst at a pressure relief source in a ground fracture area according to an embodiment of the present invention on roadway rock burst;
fig. 11 is a schematic diagram illustrating an influence of weakened top plates on roadway rock burst in the method for treating rock burst by a pressure relief source in a ground fracture area according to the embodiment of the present invention;
fig. 12 is a layout diagram of a borehole microseismic joint monitoring system in a method for treating rock burst by a pressure relief source in a ground fracture area according to an embodiment of the present invention.
Detailed Description
Referring to fig. 1, the invention provides a method for treating rock burst at a pressure relief source in a ground fracture area, which comprises the following steps:
the determination of the area with the potential rock burst hazard can be determined according to the occurrence history of rock burst of the mine or an adjacent mine, the geological conditions of the mine, the current mining condition, the recent planning and the like; referring to fig. 2, the lowest layer is a coal seam with a risk of impact, and the coal seam is the potential area of the rock burst. The rock stratum above the coal seam is called as a top plate, after the coal seam is mined out, the top plate above the coal seam is damaged under the action of gravity, and a top plate overlying rock three zones are sequentially formed from bottom to top, namely a caving zone, a fracture zone and a bending subsidence zone from bottom to top.
The method comprises the steps of determining a target rock stratum by adopting a main control key layer of coal seam mining, energy transfer response analysis, main control rock stratum analysis of microseismic monitoring and other methods, for example, determining a rock stratum which is used for mainly inducing rock burst and has a single-layer or multi-layer combined thickness of more than 20m within a range of more than 50m above a coal seam as the target rock stratum, wherein the target rock stratum has the characteristics of larger thickness, good integrity and difficult collapse after the coal seam mining.
Wherein, the analysis of the main control key layer and the energy transfer response comprises the following steps: calculating a plurality of pre-ground fractured rock layers with the fracturing performance by utilizing a key layer theory; and judging whether the target rock stratum is a final ground fracturing target rock stratum or not according to the residual energy transferred to the working face coal seam from the plurality of pre-ground fracturing rock stratums.
Wherein the determination of the remaining energy transferred from the plurality of pre-surface fractured rock formations to the face coal seam comprises: and according to the plurality of pre-ground fractured rock layers, calculating the residual energy transferred to the coal bed of the working face by utilizing the rock layer released energy attenuation characteristics.
Calculating the remaining energy transferred to the working face coal seam by the plurality of pre-ground fractured rock layers by utilizing the rock layer released energy attenuation characteristics, wherein the method comprises the following steps: performing bending energy calculation on the plurality of pre-ground fractured rock layers to obtain rock layer release energy of the plurality of pre-ground fractured rock layers; and calculating the residual energy transmitted to the working face coal seam by the rock stratum release energy of the plurality of pre-ground fractured rock strata according to the rock stratum release energy of the plurality of pre-ground fractured rock strata.
Determining a surface fracture target formation from remaining energy transferred to the face coal seam from the plurality of pre-surface fracture formations comprises: and determining the pre-ground fractured rock stratum with the maximum residual energy as a ground fractured target rock stratum by comparing the residual energy transferred to the working face coal seam by the plurality of pre-ground fractured rock strata.
The key layer theory calculation method can refer to general mechanical analysis and 2.2 section key layer discrimination methods in chapter 2 and 2.3 section key layer theories in key layer theory of rock layer control compiled by high-grade Mingming and the related contents of key layer theory of chapter 6 and second section rock layer control in mine pressure and rock layer control, so that residual energy which is transmitted to a working face coal seam according to a plurality of pre-ground fractured rock layers is convenient to obtain a ground fractured target rock layer which influences the rock burst, namely a rock burst main control rock layer.
The analysis of the primary rock formation for microseismic monitoring includes: firstly, acquiring microseismic events with different energy levels for representing the activity of surrounding rocks in a rock stratum; the method can be specifically obtained by adopting an uphole and downhole micro-seismic combined monitoring system, an uphole and downhole micro-seismic combined monitoring system or a downhole micro-seismic combined monitoring system. As a preferred embodiment, the uphole and downhole microseismic joint monitoring system shown in fig. 12 (ARP 2000 surface microseismic monitoring system of polish) can be specifically utilized, wherein the application of the ARP system realizes "armamis M/E downhole microseismic monitoring system + ARP2000P surface microseismic monitoring system" uphole and downhole joint monitoring.
Second, microseismic event analysis based on different energy levels is used to characterize whether the wall rock activity occurs primarily in the roof strata. The method specifically comprises the steps of analyzing the ratio of microseismic events or the energy of the microseismic events occurring in a top rock stratum, a coal bed and a bottom rock stratum; and when the number of the microseismic events of the top plate rock stratum is greater than the number of the microseismic events of the bottom plate rock stratum and/or the number of the microseismic events of the coal bed, or the energy of the microseismic events of the top plate rock stratum is greater than the energy of the microseismic events of the bottom plate rock stratum and/or the microseismic events of the coal bed, determining that the activity of the surrounding rock is mainly generated in the top plate rock stratum.
And thirdly, when the method is used for representing that the surrounding rock activities mainly occur in the roof rock stratum, analyzing the distributed horizons of the high-energy events in the roof rock stratum, and determining the horizons of the high-energy events which occur in a concentrated mode as the ground fracturing target rock stratum. The method specifically comprises the following steps: and according to the microseismic events monitored by the up-and-down combined microseisms and the monitored microseismic event energy level, projecting the maximum energy level event to the roof rock stratum, and determining the rock stratum with the maximum energy level microseismic event occupation ratio in the roof rock stratum as a target rock stratum.
In addition, when the maximum energy level occurrence quantity is not enough to determine the target rock stratum, continuously analyzing the secondary maximum energy level events to the rock stratum positions where the large energy events can be concentrated, and determining the target rock stratum; the insufficient number of maximum energy level occurrences is that the energy events have distributions in different lithologies (e.g., medium sandstone, fine sandstone, and/or coarse sandstone formations), and the distributions have small contrasts from formation to formation.
The microseismic monitoring master rock formation analysis and the master key layer and energy transfer response analysis can be used for determining the target rock formation independently or in combination, namely: after the main control key layer and the energy transfer response analysis are used for determining the target rock stratum, the target rock stratum determined by the main control rock stratum analysis of the microseismic monitoring is used for verifying the main control key layer and the target rock stratum determined by the energy transfer response analysis; or after the target rock stratum is determined by using the master control rock stratum analysis of the microseismic monitoring, the target rock stratum determined by the master control key layer and the target rock stratum determined by the energy transfer response analysis is verified. Through the mode of verifying whether the rock formation is consistent or not, if so, the determined target rock formation is proved to have no problem, so that the accuracy of prediction of the target rock formation is realized, and a foundation is laid for subsequent well arrangement and rock burst treatment.
step 201, determining the type of a fracturing well according to the occurrence state of a target rock stratum; types of fracturing wells include horizontal wells or vertical wells; the occurrence state comprises length and thickness.
As an example, vertical well fracturing may be used if the target formation has a fracture length of no greater than 500m and a thickness of no greater than 100 m. As an example, if the fracture length of the target rock stratum is more than 500m and the thickness is not more than 100m, horizontal well fracturing can be adopted.
Step 202, determining the well bore direction of the vertical well or the horizontal well.
As an example, when the fracturing of the vertical well is determined, the well bore of the vertical well is always kept in the vertical direction, the horizontal projection should be located in the middle of the target rock stratum, and the vertical projection should penetrate through the whole target rock stratum, see fig. 3;
as an embodiment, when the fracturing of a horizontal well is determined, the well bore of the horizontal well comprises a vertical section, a deflecting section and a horizontal section, wherein the three sections of the well bore are positioned on the same plane, the horizontal direction projection of the horizontal section should penetrate through a target rock stratum and should be consistent with the direction of the minimum horizontal main stress of the target rock stratum, and the vertical direction projection should be positioned in the middle of the target rock stratum; the vertical section is always kept in the vertical direction, and the deflecting section is used for communicating the vertical section with the horizontal section, as shown in fig. 4.
And step 203, drilling according to the well direction determined in the step 202. When drilling, the drilling equipment is used on the ground to complete the mutual matching of drilling, well cementation, well logging and other processes, so that the well body reaches the target stratum.
For vertical well drilling, referring to fig. 5, a vertical well is firstly constructed downwards from the ground, a confined aquifer or a soft and broken rock stratum may be encountered during the vertical well construction, and at the moment, well cementation is needed, and the purpose of well cementation is to separate the drilling well from an external medium and prevent the drilling well from collapsing and deforming. When the well is fixed, the casing is lowered to the bottom position, cement slurry is continuously pressed into the casing, and the cement slurry is pressed into an annular space between the casing and the well wall until the well mouth, so that the casing and the well wall form a whole body, the effect of sealing and reinforcing the exposed well wall is achieved, and the well fixing process from bottom to top is completed. After the well cementation work is finished, a small first drilling tool is adopted to continue downward construction of the vertical shaft until the bottom of the target fractured rock stratum, and the whole drilling process needs to finish the well logging work so as to obtain the geological parameters (such as lithology, natural gamma ray, compensation density and the like) of the target rock stratum.
For drilling a horizontal well, referring to fig. 6, the construction mode of the vertical section is the same as that of the vertical well, except that the construction end point of the vertical section is located in a rock stratum above a target rock stratum, the length of the vertical section is determined according to the buried depth of the target rock stratum, for example, the buried depth of the target rock stratum is 700m, and the length of the vertical section can be selected from 500-680 m. The deflecting section is a transition from the vertical section to the horizontal section, and in order to ensure the smooth operation of the drilling and fracturing procedures, the deflecting section should meet a certain radian (the curvature of the radian is not more than 90 degrees), and the radian needs to be determined in advance. When the slant well is constructed, the drilling tool is sent to the starting point position of the slant well to be drilled, and the arc-shaped slant well is constructed according to the design angle. And (3) starting to construct a horizontal section after the deflecting well is constructed to the middle part of the thickness of the target rock stratum, wherein the length of the horizontal section is determined in advance according to factors such as the range needing fracturing, the fracturing capability of fracturing equipment and the like, and the length is generally not more than 2.5 times of the length of the vertical section. And after the horizontal section is constructed to the designed position, cementing and logging are carried out again, and then the drilling process is completed. The horizontal section is used for implementing roof fracturing operation, the extending direction of the horizontal section is very important for reducing the impact risk of the region, and two points are mainly considered during design: firstly, a crack expansion zone formed after horizontal fracturing should cover a potential impact hidden danger area as much as possible; secondly, the extension direction and the minimum horizontal principal stress direction should be kept consistent as much as possible to form vertical cracks perpendicular to the horizontal section as much as possible.
In addition, the diameter of the drilled well does not exceed 500 mm. When a confined aquifer or a soft broken rock stratum is encountered in the drilling process, the drill bit and the drill rod need to be taken out, the casing pipe is put to the bottom of the confined aquifer or the soft broken rock stratum, cement slurry is injected between the casing pipe and the well wall, and the exposed rock stratum hole wall is reinforced.
And step 30, performing directional fracturing on the fracturing well after well arrangement. As an embodiment, a high-pressure hydraulic directional fracturing method can be specifically adopted, namely the method comprises the following steps: conveying perforating equipment to a well bottom, opening a perforating device to perforate on a well wall, taking out the equipment after perforation, conveying fracturing equipment to the well bottom, setting a perforating section by adopting a packer, opening a ground high-pressure pump truck to inject fracturing fluid into the perforating section along a fracturing pipeline, expanding cracks to the inside of a rock stratum, completing first fracturing, finally deblocking, moving the fracturing pipeline to other positions to be fractured, repeating setting and fracturing till fracturing construction of one well is completed, repeating a high-pressure hydraulic directional fracturing process to complete fracturing construction of other wells, and forming mutually-communicated reticular cracks in a target rock stratum. Referring specifically to fig. 7 and 8, the perforating device is pushed to the bottom position of the fractured well, the perforating device is started to generate high-pressure gas or liquid, and the high-pressure gas or liquid is emitted from the nozzle of the perforating device, the pressure of the high-pressure gas or liquid far exceeds the sum of the shear strength and the maximum horizontal stress of the well wall (including casing, cement and rock), so that a fracture perpendicular to the fractured well is formed at the nozzle position of the well wall. And taking out the perforating device, conveying the fracturing device to the perforating section, pressurizing the packers at the two ends to expand and extrude the well wall to complete setting, so that a closed space can be formed in the perforating section. And starting the ground high-pressure pump, continuously injecting fracturing fluid into the perforating section along the high-pressure pipeline, preparing the fracturing fluid by water and chemical agents according to a certain proportion, expanding the cracks formed by perforating towards the deep part under the action of the high-pressure fluid, forming reticular cracks with different directions, widths and lengths on the periphery of the main cracks, and closing the high-pressure pump to finish primary fracturing after the designed fracturing time is reached or the pressure is reduced to a certain value. And releasing the pressure of the packer to separate the packer from the well wall, completing deblocking, and dragging the fracturing pipeline to move back to the next fracturing position after deblocking. And repeating the fracturing process to complete the fracturing procedure of the whole horizontal well in sequence.
And completing the drilling and fracturing construction process of other wells according to the method.
Referring to fig. 9, before coal seam mining, the mining area needs to be enclosed by roadways, and the roadways can meet the requirements of pedestrians, ventilation, transportation and the like during coal mining. The area enclosed by the roadway is referred to as the face, each face acting as an independent mining unit. The transport gateway in fig. 9 is a tunnel mainly used for transporting coal and intake air, and the return air gateway is a tunnel mainly used for transporting materials and return air. As a specific implementation manner of the embodiment of the invention, the roadways to be protected are a 101 transportation crossheading, a 102 return air crossheading and a 103 return air crossheading, and all of the roadways have potential rock burst risks, and during design and construction of the roadways, the protected roadway should be arranged according to the position of the horizontal well, so that the protected roadway is as close to the area right below the horizontal well as possible, and the trend of the roadway is kept parallel to the direction of the horizontal well, so that the roadway is in the most effective pressure relief protection range.
Referring to fig. 10 and 11, through the modification and pressure relief of the large-area roof, a large number of interconnected network-shaped fractures are formed in the target fractured rock stratum, the overall strength of the rock stratum is greatly reduced, and when the stress of the rock stratum above the target fractured rock stratum is transferred downwards, the hard transfer before modification is converted into soft transfer, so that the overall stress level of the coal seam below the target fractured rock stratum is reduced.
In the coal seam mining process, the coal seam mining sequence should be: firstly mining a 101 working face, then mining a 103 working face and finally mining a 102 working face, and analyzing the influence of roof modification pressure relief on roadway rock burst by taking the impact risk during mining of the 102 working face as an example.
After the 101 working face is mined out, part of the pressure of the top plate above the 101 working face acts on the 102 return air gateway, and after the 103 working face is mined out, part of the pressure of the top plate above the 103 working face acts on the 102 transportation gateway, so that lateral stress concentration areas are formed near the 102 return air gateway and the transportation gateway respectively; meanwhile, the 102 working face is mining and is influenced by continuous mining of the coal seam, and part of the pressure of the top plate of the rear goaf acts on the coal body in front of the goaf, so that a strike stress concentration area is formed in the area where the two gate roads are close to the 102 goaf. The higher the stress concentration, the higher the probability of rock burst occurring, and the higher the energy released by rock burst.
Referring to fig. 10, because the thick-layer hard top plate is not modified for pressure relief, the top plate has high strength and good integrity, so that after coal is mined, the top plate is not easy to collapse to form a large-area suspended roof, the larger the suspended roof area is, the higher the stress acting on coal bodies near 102 two gate roads is, and meanwhile, the large-area suspended roof is suddenly broken to generate a strong dynamic pressure effect, so that the stress of the coal bodies near a roadway is suddenly increased, and when the stress of the coal bodies exceeds the critical stress triggering rock burst, the elastic energy accumulated in the coal bodies is suddenly released, and the roadway damage, equipment damage and casualties are caused in serious cases.
Referring to fig. 11, since the thick-layer hard top plate is modified and pressure-relieved in advance, the strength and integrity of the rock stratum are greatly reduced, the top plate can collapse in time along with the mining of coal to fill a goaf, so that the upper rock stratum is supported, partial stress of coal bodies around a roadway is shared, and the stress of the coal bodies is always below the critical stress of rock burst, thereby fundamentally eliminating the serious threat of the rock burst to safety production.
The method for treating rock burst by the pressure relief source in the ground fracturing area adopts the method of modifying and relieving pressure of the thick-layer hard top plate by using ground hydraulic fracturing, so that a plurality of reticular cracks with different directions and lengths are formed in a rock stratum with good integrity, the integral strength of the rock stratum is greatly reduced, the stress distribution of a strong impact dangerous coal bed below the rock stratum is reduced, and the serious impact disaster risk during the coal bed mining process is fundamentally eliminated. In addition, the method for treating rock burst at the pressure relief source of the ground fracturing area belongs to strategic treatment measures of rock burst, has important significance on the progress of the rock burst prevention and treatment technology and concept in China, and has remarkable social and economic benefits.
Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.
Claims (10)
1. A method for treating rock burst by a pressure relief source in a ground fracturing area is characterized by comprising the following steps:
determining a target rock stratum needing modification and pressure relief in an area with the potential risk of rock burst;
determining a well arrangement mode of a fractured well in the target rock stratum, and drilling the well; the fracturing well comprises a horizontal well or a vertical well;
and performing directional fracturing on the fractured well after drilling.
2. The method of claim 1, further comprising determining a potential impact pressure hazard zone, the determining a potential impact pressure hazard zone comprising: and determining the area with the potential impact ground hazard according to the actual conditions of the mine or the adjacent mine, wherein the actual conditions comprise the occurrence history of the impact ground pressure, the geological conditions of the mine and the current mining conditions.
3. The method of claim 1, wherein identifying a target rock formation for which modified pressure relief is desired in an area where a potential impact pressure hazard exists comprises:
and determining a target rock stratum needing modification and pressure relief by adopting a main control key layer for coal mining and a main control key layer analysis method for energy transfer response analysis and/or microseismic monitoring based on mine geological data above the rock burst hidden danger area.
4. The method of claim 1, wherein determining a pattern of fractured wells in the target formation comprises:
determining the type of a fracturing well according to the occurrence state of the target rock stratum; types of fracturing wells include horizontal wells or vertical wells; the occurrence state comprises length and thickness;
and determining the well direction of the vertical well or the horizontal well.
5. The method of claim 4, wherein determining a well direction for a vertical or horizontal well comprises:
when the fracturing of the vertical well is determined, the well body of the vertical well always keeps the vertical direction, the horizontal projection is positioned in the middle of the target rock stratum, and the vertical projection penetrates through the whole target rock stratum;
when the fracturing of the horizontal well is determined, the well body of the horizontal well comprises a vertical section, an inclined section and a horizontal section, wherein the three sections of the well body are positioned on the same plane, the horizontal direction projection of the horizontal section should penetrate through a target rock stratum and should be consistent with the minimum horizontal main stress direction of the target rock stratum, and the vertical direction projection should be positioned in the middle of the target rock stratum; the direction of the vertical section is always kept in the vertical direction; the deflecting section is connected with the vertical section and the horizontal section; the direction of the minimum principal stress in the target rock stratum is perpendicular to the direction of the maximum horizontal principal stress; the direction of the maximum horizontal principal stress is the initial fracture orientation of the rock of the target formation at the time of hydraulic fracturing.
6. The method of claim 5, further comprising determining a minimum horizontal principal stress direction for the target formation, including:
conveying hydraulic fracturing equipment into a target rock stratum, and sealing the upper end and the lower end of a fracturing section by using a packer;
injecting high-pressure liquid, pressurizing until the rock is cracked, and taking the initial cracking direction as the direction of the maximum horizontal principal stress;
and taking the direction vertical to the direction of the maximum horizontal principal stress as the direction of the minimum horizontal principal stress.
7. The method of claim 1, wherein the high pressure hydraulic directional fracturing the frac well comprises:
perforating on the wall of a well, after perforating, setting the perforation section, injecting fracturing fluid into the perforation section along the fracturing pipeline, making the crack to the inside extension of rock stratum, accomplishing first fracturing, deblocking at last, removing the fracturing pipeline to other positions of treating the fracturing, repeatedly setting and fracturing to the fracturing construction of accomplishing a well.
8. The method of claim 7, wherein the high pressure hydraulic directional fracturing the frac well further comprises:
after one well completes fracturing construction, the high-pressure hydraulic directional fracturing procedure is repeated to complete the fracturing construction of other wells, so that mutually communicated net-shaped cracks are formed in the target rock stratum.
9. The method of claim 1, further comprising arranging a roadway with potential rock burst risk in an area immediately below the horizontal well during roadway design construction, and keeping the roadway running parallel to the horizontal well direction to place the roadway within the most effective pressure relief protection range, wherein the roadway comprises a transport gateway, a return air gateway and a return air gateway.
10. The method of any one of claims 1-9, wherein the target rock formation is a predominantly rock formation inducing rock burst having a combined thickness of greater than 20m in single or multiple layers and a distance of greater than 50m from the potential zone of the rock burst.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811518097X | 2018-12-12 | ||
| CN201811518097.XA CN109736805A (en) | 2018-12-12 | 2018-12-12 | A kind of method of the modified release watershed management bump of thick-layer tight roof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110939442A true CN110939442A (en) | 2020-03-31 |
| CN110939442B CN110939442B (en) | 2021-07-27 |
Family
ID=66358811
Family Applications (4)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811518097.XA Pending CN109736805A (en) | 2018-12-12 | 2018-12-12 | A kind of method of the modified release watershed management bump of thick-layer tight roof |
| CN201911277065.XA Active CN111005723B (en) | 2018-12-12 | 2019-12-12 | Ground large-range rock stratum pre-splitting area anti-impact method based on up-down combined arrangement |
| CN201911276023.4A Active CN110939442B (en) | 2018-12-12 | 2019-12-12 | Method for treating rock burst by pressure relief source in ground fracturing area |
| CN201911276513.4A Active CN111005722B (en) | 2018-12-12 | 2019-12-12 | Well arrangement method for governing rock burst at pressure relief source of ground fracturing area |
Family Applications Before (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811518097.XA Pending CN109736805A (en) | 2018-12-12 | 2018-12-12 | A kind of method of the modified release watershed management bump of thick-layer tight roof |
| CN201911277065.XA Active CN111005723B (en) | 2018-12-12 | 2019-12-12 | Ground large-range rock stratum pre-splitting area anti-impact method based on up-down combined arrangement |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911276513.4A Active CN111005722B (en) | 2018-12-12 | 2019-12-12 | Well arrangement method for governing rock burst at pressure relief source of ground fracturing area |
Country Status (1)
| Country | Link |
|---|---|
| CN (4) | CN109736805A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111859712A (en) * | 2020-08-03 | 2020-10-30 | 重庆大学 | Ground advanced pre-control method for coal mine rock burst |
| CN113738366A (en) * | 2021-09-30 | 2021-12-03 | 重庆大学 | Rock burst and gas overrun cooperative control method for fold structural area |
| CN113818922A (en) * | 2021-10-25 | 2021-12-21 | 重庆大学 | Fold type rock burst control method based on ground fracturing and liquid explosive blasting |
| CN114481740A (en) * | 2022-02-21 | 2022-05-13 | 中交路桥建设有限公司 | Construction method for drilling, crushing and rolling cement pavement |
| CN115898261A (en) * | 2022-10-14 | 2023-04-04 | 中国矿业大学 | Gob-side entry retaining low-position roof cutting and high-position directional fracturing stress transfer method and device |
| CN116049964A (en) * | 2023-02-08 | 2023-05-02 | 中煤科工开采研究院有限公司 | Anti-impact method for artificial liberation layer of newly-built mine |
| CN116258000A (en) * | 2023-02-08 | 2023-06-13 | 中煤科工开采研究院有限公司 | Anti-impact method for artificial liberation layer |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110792419B (en) * | 2019-10-18 | 2021-07-16 | 太原理工大学 | Coal mine rock burst well up-down advance pre-control method |
| CN111077576A (en) * | 2019-12-12 | 2020-04-28 | 天地科技股份有限公司 | Ground fracturing monitoring method |
| CN111270987B (en) * | 2020-01-20 | 2020-12-25 | 中国矿业大学 | Method for accurately preventing and controlling rock burst in remote area under coal mine |
| CN111852566A (en) * | 2020-07-07 | 2020-10-30 | 中煤科工开采研究院有限公司 | Microseismic monitoring method for coal mine underground hydraulic fracturing crack propagation rule |
| CN112012797A (en) * | 2020-09-03 | 2020-12-01 | 兖州煤业股份有限公司 | Evaluation method for coal mine impact danger pressure relief effect |
| CN112324418B (en) * | 2020-11-30 | 2022-03-29 | 中国石油集团渤海钻探工程有限公司 | Hydraulic breaking process for underground rock |
| CN112483089A (en) * | 2020-12-18 | 2021-03-12 | 山东科技大学 | One-movement multi-static protection method for working face lateral suspended roof type rock burst |
| CN112780340B (en) * | 2021-01-05 | 2023-08-29 | 陕西彬长孟村矿业有限公司 | Method for preventing rock burst in advance in underground coal mine area |
| CN113047823B (en) * | 2021-04-08 | 2023-01-24 | 中国石油天然气股份有限公司 | Method and device for determining horizontal well spacing strategy |
| CN113339073B (en) * | 2021-07-06 | 2022-06-24 | 中国矿业大学 | Impact risk evaluation method based on roof rock stratum structure |
| CN113404535B (en) * | 2021-07-07 | 2023-05-02 | 陕西彬长孟村矿业有限公司 | Method for preventing rock burst by hydraulic fracturing of coal mine underground |
| CN113669059B (en) * | 2021-07-31 | 2022-05-13 | 中国矿业大学 | Coal mine rock burst prevention and hydraulic fracturing cutting top pressure relief method |
| CN113847083B (en) * | 2021-10-28 | 2024-03-01 | 重庆大学 | Control method for rock burst of high-level huge-thickness hard top plate area |
| CN113898400B (en) * | 2021-11-01 | 2022-10-28 | 重庆大学 | Hard roof empty roadway rock burst control method based on ground fracturing |
| CN114542005B (en) * | 2022-02-17 | 2024-03-15 | 山东科技大学 | Pressure-injection integrated packer device for hydraulic fracturing of hard thick-roof coal |
| CN114776272B (en) * | 2022-05-25 | 2022-11-22 | 中国矿业大学(北京) | Pressure-relief permeability-increasing method for overlying key layer of hydraulic fracturing |
| CN115288681A (en) * | 2022-08-03 | 2022-11-04 | 中煤科工开采研究院有限公司 | Method for preventing rock burst at fracture source in coal mine roof area |
| CN116050171B (en) * | 2023-02-08 | 2024-03-08 | 中煤科工开采研究院有限公司 | Anti-impact method for artificial liberation layer of tunneling roadway |
| CN115929304B (en) * | 2023-02-08 | 2024-02-23 | 中煤科工开采研究院有限公司 | Method for preventing impact of artificial relief layer of stope face |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102080526A (en) * | 2011-01-17 | 2011-06-01 | 河南理工大学 | Method for extracting gas from bedding level fractured well of ground coal seam roof |
| CN102678120A (en) * | 2012-05-18 | 2012-09-19 | 河南大有能源股份有限公司 | Method for releasing pressure and removing danger of rock burst |
| CN108590654A (en) * | 2018-03-16 | 2018-09-28 | 天地科技股份有限公司 | The coal mine rock burst confirmed based on load source sound region divides source control method |
| CN108756884A (en) * | 2018-06-12 | 2018-11-06 | 王帆 | Coal mine tight roof full face ground shifts to an earlier date outburst elimination method |
| CN108843320A (en) * | 2018-06-12 | 2018-11-20 | 王帆 | Shift to an earlier date outburst elimination method in the tunnel of coal mine tight roof full face |
| CN108894813A (en) * | 2018-06-20 | 2018-11-27 | 北京九尊能源技术股份有限公司 | The gas outburst elimination method that downhole drill, ground fracturing and underground extraction combine |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10309205B2 (en) * | 2011-08-05 | 2019-06-04 | Coiled Tubing Specialties, Llc | Method of forming lateral boreholes from a parent wellbore |
| CN105019935A (en) * | 2014-04-16 | 2015-11-04 | 郑州大学 | Overground/underground combined pressure relief outburst elimination coal seam rapid channel digging method |
| CN105089493B (en) * | 2014-05-13 | 2018-10-23 | 郑州大学 | Ground vertical well combines pressure released seam gas pumping method with underground layer-through drilling |
| CN105201480B (en) * | 2015-10-14 | 2017-09-26 | 山西晋煤集团技术研究院有限责任公司 | Surface well underground long drilled holes pressure break coal seam method |
| CN105807312B (en) * | 2016-03-15 | 2018-01-26 | 大连理工大学 | Coal mine roof plate rock mass vertical zoning based on micro seismic monitoring determines method |
| CN106150503B (en) * | 2016-07-05 | 2018-06-01 | 重庆大学 | A kind of method that tight roof is administered in hydraulic fracturing |
| CN106285679B (en) * | 2016-08-11 | 2018-07-10 | 太原理工大学 | A kind of presplitting and the method for softening igneous rock tight roof |
| CN108571307A (en) * | 2017-03-10 | 2018-09-25 | 中国石油集团钻井工程技术研究院 | A kind of enhanced geothermal system pressure-break net design and completion method |
| CN107905832A (en) * | 2017-11-06 | 2018-04-13 | 北京九尊能源技术股份有限公司 | The outburst elimination method of pump drainage is combined on a kind of nitrogen pressure break and ground with underground |
| CN107905834A (en) * | 2017-12-20 | 2018-04-13 | 中原工学院 | A kind of hypotonic high prominent coal seam architecture gas production method |
| CN108643960A (en) * | 2018-05-21 | 2018-10-12 | 河南工程学院 | A kind of ground region band coal mine gas extinction technique |
-
2018
- 2018-12-12 CN CN201811518097.XA patent/CN109736805A/en active Pending
-
2019
- 2019-12-12 CN CN201911277065.XA patent/CN111005723B/en active Active
- 2019-12-12 CN CN201911276023.4A patent/CN110939442B/en active Active
- 2019-12-12 CN CN201911276513.4A patent/CN111005722B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102080526A (en) * | 2011-01-17 | 2011-06-01 | 河南理工大学 | Method for extracting gas from bedding level fractured well of ground coal seam roof |
| CN102678120A (en) * | 2012-05-18 | 2012-09-19 | 河南大有能源股份有限公司 | Method for releasing pressure and removing danger of rock burst |
| CN108590654A (en) * | 2018-03-16 | 2018-09-28 | 天地科技股份有限公司 | The coal mine rock burst confirmed based on load source sound region divides source control method |
| CN108756884A (en) * | 2018-06-12 | 2018-11-06 | 王帆 | Coal mine tight roof full face ground shifts to an earlier date outburst elimination method |
| CN108843320A (en) * | 2018-06-12 | 2018-11-20 | 王帆 | Shift to an earlier date outburst elimination method in the tunnel of coal mine tight roof full face |
| CN108894813A (en) * | 2018-06-20 | 2018-11-27 | 北京九尊能源技术股份有限公司 | The gas outburst elimination method that downhole drill, ground fracturing and underground extraction combine |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111859712A (en) * | 2020-08-03 | 2020-10-30 | 重庆大学 | Ground advanced pre-control method for coal mine rock burst |
| CN111859712B (en) * | 2020-08-03 | 2023-11-21 | 重庆大学 | Ground advance pre-control method for rock burst of coal mine |
| CN113738366A (en) * | 2021-09-30 | 2021-12-03 | 重庆大学 | Rock burst and gas overrun cooperative control method for fold structural area |
| CN113738366B (en) * | 2021-09-30 | 2022-08-16 | 重庆大学 | Rock burst and gas overrun cooperative control method for fold structural area |
| CN113818922A (en) * | 2021-10-25 | 2021-12-21 | 重庆大学 | Fold type rock burst control method based on ground fracturing and liquid explosive blasting |
| CN114481740A (en) * | 2022-02-21 | 2022-05-13 | 中交路桥建设有限公司 | Construction method for drilling, crushing and rolling cement pavement |
| CN115898261A (en) * | 2022-10-14 | 2023-04-04 | 中国矿业大学 | Gob-side entry retaining low-position roof cutting and high-position directional fracturing stress transfer method and device |
| CN115898261B (en) * | 2022-10-14 | 2023-08-15 | 中国矿业大学 | Gob-side entry retaining low-level roof cutting and high-level directional fracturing stress transfer method and equipment |
| CN116049964A (en) * | 2023-02-08 | 2023-05-02 | 中煤科工开采研究院有限公司 | Anti-impact method for artificial liberation layer of newly-built mine |
| CN116258000A (en) * | 2023-02-08 | 2023-06-13 | 中煤科工开采研究院有限公司 | Anti-impact method for artificial liberation layer |
| CN116049964B (en) * | 2023-02-08 | 2024-02-13 | 中煤科工开采研究院有限公司 | Anti-impact method for artificial liberation layer of newly-built mine |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109736805A (en) | 2019-05-10 |
| CN111005722A (en) | 2020-04-14 |
| CN111005723A (en) | 2020-04-14 |
| CN111005722B (en) | 2021-11-02 |
| CN110939442B (en) | 2021-07-27 |
| CN111005723B (en) | 2021-11-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110939442B (en) | Method for treating rock burst by pressure relief source in ground fracturing area | |
| CN113404535B (en) | Method for preventing rock burst by hydraulic fracturing of coal mine underground | |
| CN112593936B (en) | Advanced comprehensive control method for multi-disaster area of deep mine | |
| WO2023273091A1 (en) | Method for preventing and controlling rock bursts in development roadway group | |
| CN112780340B (en) | Method for preventing rock burst in advance in underground coal mine area | |
| CN102392677A (en) | Permeability improvement technology for coal bed gas reservoir cap by using three-dimensional fracture network modification | |
| CN111159856B (en) | Target rock stratum determination method for pressure relief and impact prevention of ground fracturing area | |
| CN108894813B (en) | Gas outburst elimination method combining underground drilling, ground fracturing and underground extraction | |
| CN111520184A (en) | Comprehensive control system and method for coal mine rock burst and harmful gas | |
| CN106150501A (en) | Utilize the method that Overburden gob area situ waste water weakens master control coal rock layer | |
| CN112576305B (en) | Method for preventing and controlling water damage of working surface separation layer | |
| CN109162731A (en) | Iron producing area deep mining gushing water grouting treatment method | |
| CN113404534A (en) | Method for preventing rock burst by staged fracturing of L-shaped ground horizontal well | |
| CN114294046B (en) | Coal mine area full-coverage underground three-dimensional extraction method | |
| RU2109948C1 (en) | Method of optimized orientation of breakage faces, specifically on coal deposit | |
| Jeffrey et al. | Sand Propped hydraulic fracture stimulation of horizontal in-seam gas drainage holes at Dartbrook Coal Mine | |
| Xie et al. | Reasonable stopping method and retracement channel support at fully mechanized top coal caving working face of 15 m extra‐thick coal seam: A case study | |
| Huang et al. | Field experiment of destress hydraulic fracturing for controlling the large deformation of the dynamic pressure entry heading adjacent to the advancing longwall face | |
| CN111894672B (en) | Method for advanced treatment of roof separation water damage of stope by adopting ground drainage drilling | |
| CN212318072U (en) | Colliery rock burst and harmful gas comprehensive control system | |
| Zhang et al. | Experimental study ON the joint application OF innovative techniques for the improved drivage OF roadways at depths over 1 KM: a case study | |
| CN116971778B (en) | Method for preventing and controlling hard roof rock burst of coal mine by ground composite fracturing | |
| CN114233369B (en) | Method for precisely eliminating coal and gas outburst by up-and-down combination | |
| CN117027802B (en) | Method for preventing and controlling coal mine rock burst in advance in ground horizontal well segmented fracturing area | |
| RU2163968C2 (en) | Method of cover caving |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |