CN115717529B - Method for evaluating construction effect of protective layer in coal seam - Google Patents
Method for evaluating construction effect of protective layer in coal seam Download PDFInfo
- Publication number
- CN115717529B CN115717529B CN202211470498.9A CN202211470498A CN115717529B CN 115717529 B CN115717529 B CN 115717529B CN 202211470498 A CN202211470498 A CN 202211470498A CN 115717529 B CN115717529 B CN 115717529B
- Authority
- CN
- China
- Prior art keywords
- coal
- holes
- measure
- hole
- unloading
- 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.)
- Active
Links
Images
Landscapes
- Testing Or Calibration Of Command Recording Devices (AREA)
- Management, Administration, Business Operations System, And Electronic Commerce (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention provides a method for evaluating the construction effect of a protective layer in a coal seam, which comprises the following steps: s1, measuring gas parameters of a single outburst coal seam; s2, arranging a plurality of groups of investigation holes in a coal seam floor rock roadway towards a coal seam, and measuring the coal unloading quantity of the investigation holes and the expansion deformation quantity of surrounding coal bodies; s3, determining an effective control range corresponding to the investigation holes on the basis that the expansion deformation of the coal body around the investigation holes is more than or equal to 3 per mill, and determining coal unloading indexes of the inner protection layer, the measure holes and the measure hole units; s4, implementing coal unloading measures according to unit coal unloading indexes of the measure holes, and accurately measuring the coal unloading amount of each measure hole; s5, calculating accumulated coal unloading quantity of the measure holes, and judging whether the effectiveness of the measure meets the standard; s6, after the implementation of the coal unloading measures is finished, dividing rectangular units, and detecting whether a pressure relief blank area exists in a coal bed in the rectangular units; s7, judging the protection effect of the protective layer in the coal layer; and if the pressure relief blank area does not exist, judging that the protection effect of the protective layer in the coal layer reaches the standard.
Description
Technical Field
The invention relates to the technical field of coal mine gas control, in particular to a method for evaluating the construction effect of a protective layer in a coal seam, which is suitable for regional control of single-outburst thick coal seam gas.
Background
The coal-bearing rock system in China has complex structure, various forms and poor air permeability, and the occurrence of coal and gas outburst accidents seriously restricts the safe and efficient mining of the coal mine. The regulations of the safety regulations of coal mines and a large number of engineering practices show that the mining of the protective layer can change the stress environment of coal and rock, release accumulated elastic energy, destroy surrounding rock structures and the like, so that the pressure reduction of coal seam gas and the increase of the mechanical strength of coal caused by the pressure relief of the protective layer are realized, and the risk of coal seam protrusion is eliminated or reduced.
However, the mining of the protective layer has specific applicability conditions, and has good safety and economic benefit for the close coal seam group, particularly the coal seam group with no outburst dangerous coal seam, but most mines can only select the adjacent non-mined coal seam or rock stratum as the protective layer, and the mining of the protective layer is implemented by adopting a coal-rock simultaneous mining method. Particularly, for the first coal seam of a part of single outburst thick coal seam or short-distance coal seam group, the upper/lower protective layer relation cannot be formed because the rock stratum of the top and bottom plates is hard or has serious water bursting danger, the measures of pre-pumping coal seam gas by sequential or through-layer drilling are mainly adopted to carry out gas control, and the residual gas content or pressure index of the coal seam is tested to carry out the test of the measure control effect. Because the control range of drilling extraction is limited, the outburst elimination purpose is achieved mainly by reducing the coal seam gas pressure in the extraction area, and compared with the protection layer extraction technology, the effect gap is obvious.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a safe, reliable and high-applicability method for evaluating the construction effect of a protective layer in a coal seam.
In order to achieve the above object, the technical scheme of the present invention is as follows:
the method for evaluating the construction effect of the protective layer in the coal seam comprises the following steps:
s1, measuring the original gas content, the original gas pressure, the average thickness of a coal bed and the firmness coefficients of different layers of the coal bed of a single outburst coal bed by using a through-layer drilling method;
wherein the determination of the coal's firmness coefficient is based on the determination of the coal and petrophysical mechanical properties method section 12: the method for measuring the firmness coefficient of coal (GB/T23561.12-2010).
S2, arranging a plurality of groups of investigation holes in a coal seam floor rock roadway towards the coal seam, implementing different-scale coal unloading measures on each group of investigation holes, accurately measuring the coal unloading quantity of each investigation hole, and measuring the expansion deformation quantity of coal bodies around the investigation holes;
s3, determining an effective control range corresponding to the investigation holes based on the fact that the expansion deformation of the coal body around the investigation holes is more than or equal to 3 per mill, separating the coal layer from the inner protection layer by combining the arrangement characteristics of the coal layer mining working face and the succession requirements, and determining the coal unloading indexes of the inner protection layer, the measure holes and the measure hole units;
s4, implementing coal unloading measures according to unit coal unloading indexes of the measure holes, and accurately measuring the coal unloading amount of each measure hole; when the coal discharge amount of the measure hole is larger than or equal to the unit coal discharge index, the measure hole finishes the coal discharge measure, and when the coal discharge amount of the measure hole is smaller than the unit coal discharge index, the measure hole continues to execute the coal discharge measure;
s5, calculating accumulated coal unloading quantity of the measure holes, and judging whether the effectiveness of the measure meets the standard; if the standard is reached, step S6 is carried out; if the coal discharge amount does not reach the unit coal discharge index, repeating the step S4, namely continuously implementing coal discharge measures between adjacent measure holes of which the coal discharge amount does not reach the unit coal discharge index;
s6, after the coal unloading measures are implemented, dividing a measure hole control area into rectangular units with the diameter of 30m multiplied by 30m, and detecting whether a pressure relief blank area exists in a coal bed in the rectangular units by adopting a hole pit penetration detection method;
s7, judging the protection effect of the protective layer in the coal layer; if the pressure relief blank area does not exist, judging that the protection effect of the protective layer in the coal layer reaches the standard, and performing step S8; if the pressure relief blank area exists, judging that the protection effect of the protective layer in the coal layer does not reach the standard, repeating the step S4, and continuing to implement coal unloading measures in the pressure relief blank area;
s8, checking the effect of the inner protective layer measures, and after all drilling pressures are in a non-negative pressure state within the test range, measuring the drilling gas pressure and the gas content according to a program, wherein the measurement result meets the related requirements of the rules of preventing and treating coal and gas outburst.
As an improvement to the technical scheme, the investigation holes are arranged in the bottom plate rock roadway according to investigation requirements, are perpendicular to the roadway center line and are provided with 1 or 1 row of a plurality of through-layer drilling holes in fan-shaped distribution, the final positions of the investigation holes penetrate through a coal seam top plate to be not less than 0.5m, and each group of investigation holes are spaced by 20m to avoid cross influence.
As an improvement to the above technical solution, consider the coal unloading measures of holes or measure holes, including but not limited to coal unloading measures using hydraulic punching, slotting, mechanical reaming; the integrity of the coal seam is destroyed by adopting hydraulic power or mechanical power, and the crushed coal body is formed into holes (inner protection layers) with a certain shape in the coal seam by investigation holes or measures Kong Xiechu, so that the purpose of providing expansion deformation space for the residual coal body in the investigation holes or measure hole control area is achieved.
As an improvement to the above technical solution, the holes (inner protection layer) or the continuous holes (inner protection layer) parallel to the coal seam are formed after the layered coal body with smaller firmness coefficient in the coal seam is continuously discharged (as shown in fig. 2); or in the form of a plurality of independent or partially independent holes (inner protective layers) orthogonal or diagonal to the coal seam (as shown in fig. 3).
As an improvement of the above technical solution, the different scales of step S2 implement different strengths according to the amount of coal discharged from one inspection hole, and each inspection hole of the same group implements the same scale of coal discharging measures.
As an improvement to the technical scheme, the coal unloading amount in the step S2 is the quality of coal body unloaded from the investigation hole after the investigation hole adopts the coal unloading measure.
As an improvement to the technical scheme, the expansion deformation measurement in the step S2 means that a plurality of groups of horizon positioners are arranged in a range of 5m to 10m on two sides of the investigation hole in advance, each group of horizon positioners are arranged at intervals of 1m along the center line of the bottom plate rock roadway, and the horizon deformation of the coal seam roof, the coal seam bottom plate and the coal seam before and after the coal unloading measures are implemented in the investigation hole is respectively monitored.
As an improvement of the above-mentioned technical solution, the effective control range in step S3 is a range covered by a circle having a radius from a position where the expansion deformation amount of the coal body around the inspection hole is 3% or more to the center of the inspection hole.
As an improvement to the technical scheme, the measure holes in the step S3 are arranged in the bottom plate rock roadway according to the requirement of coal seam gas management, are perpendicular to the roadway central line and are in fan-shaped distribution, the measure holes penetrate through the coal seam roof to be not less than 0.5m, the maximum distance between every two adjacent measure holes is not more than 2 times of the effective control range of the corresponding unit coal unloading index, and no control blank area exists between every two adjacent measure holes.
As an improvement to the technical scheme, the unit coal unloading index in the step S3 accords with the minimum coal unloading amount of the unit coal hole section length of the measure holes of the design space of the measure holes, and takes the invention as an example, the unit coal unloading index is 0.5t/m (coal hole section) which is determined as the coal unloading amount of the measure hole coal section 1 m.
As an improvement of the above technical solution, the measure effectiveness determination formula in step S5 is as follows:
C total (S) Not less than n.C, wherein C Total (S) Is the measure ofAccumulating coal unloading quantity of the holes, wherein the unit is t; n is the number of measure holes; c is a unit coal unloading index, and the unit is t;
as an improvement to the above technical solution, the accumulated coal unloading amount calculation formula in step S5 is:
C total (S) =C 1 +C 2 +C 3 +……+C n Wherein C 1 The coal unloading amount of the first measure hole is t; c (C) 2 The unit of the coal unloading amount is t; c (C) n The unit of the coal unloading amount of the nth measure hole is t.
As an improvement to the above technical solution, in the method for detecting pit penetration between holes in step S6, the holes are detected by using a fixed-point method by dividing the edges of rectangular units, and the method performs fixed-point emission and multipoint reception: the method comprises the steps that an emission probe and a receiving probe are respectively arranged on two measuring channels (a left side edge measuring hole and a right side edge measuring hole of a rectangular unit), high-frequency radio wave signals sent by the same point emission probe are received (fan-shaped receiving) by the receiving probe at a corresponding point of the other measuring channel, the positions of the emission probe and the receiving probe are alternately changed, and after all detection is carried out on a rectangular unit coal seam between two opposite measuring channels, a pressure relief blank area inside the rectangular unit coal seam is drawn in an intersection mode. And then the inter-well penetration detection of each rectangular unit is completed in the same manner.
As an improvement to the above technical scheme, in the step S6, the relative positions of the transmitting probe and the receiving probe in the coal seam are exemplified by the invention, the positions of the transmitting probe and the receiving probe are the coal seam roof position, the coal seam middle position and the coal seam floor position, and in the hole pit penetration detection implementation process, the positions of the transmitting probe and the receiving probe are consistent, namely, the transmitting probe and the receiving probe are positioned at the coal seam roof position or at the coal seam floor position at the same time.
As an improvement to the technical scheme, after the inner protective layer is mined in the steps S3 and S7, compared with the interlayer protective layers (the upper protective layer and the lower protective layer), the inner protective layer is promoted to expand and deform, the power of protruding occurrence of protruding is eliminated, the coal unloading measure is implemented in the coal layer, and an expansion deformation space is provided for the residual coal body of the same coal layer, so that the purpose of eliminating the power of protruding occurrence of protruding in the coal layer is achieved.
Compared with the prior art, the invention has the advantages and positive effects that:
the invention provides a coal seam inner protection layer construction effect evaluation method which is safe and reliable and has strong applicability, aiming at the distribution characteristics of a single coal seam, an inner protection layer is formed at a certain layer position of the coal seam or between adjacent holes by adopting a composite coal unloading measure combining drilling, punching and expanding, so that the pressure of the residual coal body of the coal seam is relieved, and the power of the occurrence of the protrusion is eliminated; monitoring the expansion deformation of the coal seam before and after the coal unloading measure by using a horizon locator, and examining the effective control range and unit coal unloading index of the coal unloading measure, so as to provide a basis for the design of the parameters of the coal unloading measure; and the hole-to-hole pit penetration is adopted to detect the pressure relief blank area, so that the protection effect of the protective layer in the coal layer is evaluated, and the measure reliability is further improved.
Compared with the exploitation of conventional interlayer protective layers (upper/lower protective layers), the method improves the applicability and reliability of measures, solves the difficult problem of pressure relief outburst elimination safety exploitation of a single outburst thick coal seam or a short-distance coal seam group first exploitation outburst coal seam, changes the gas control mode for realizing outburst elimination by means of extraction only, effectively improves the pressure relief effect of the coal seam and shortens the gas control period.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.
FIG. 1 is a flow chart of an embodiment of the method of the present invention;
fig. 2a and 2b are schematic diagrams of coal unloading and depressurization of the protective layer in the protruding coal layer (continuous holes (inner protective layer) parallel to the coal layer); wherein fig. 2a is formed before pressure relief and fig. 2b is formed after pressure relief;
fig. 3a and 3b are schematic diagrams of coal unloading and depressurization of the protection layer in the protruding coal layer (forming orthogonal or diagonal holes (inner protection layer) with the coal layer); wherein FIG. 3a is formed before pressure relief and FIG. 3b is formed after pressure relief;
FIG. 4 is a schematic diagram of a hole arrangement and rectangular cell division;
FIGS. 5a, 5b and 5c are schematic views showing connection of the device for detecting penetration between holes; fig. 5a is a schematic diagram of connection of a pit penetration detection device between position point holes of a coal seam roof, fig. 5b is a schematic diagram of connection of a pit penetration detection device between position point holes of a coal seam middle position point, and fig. 5c is a schematic diagram of connection of a pit penetration detection device between position point holes of a coal seam floor;
FIGS. 6a, 6b, 6c, 6d, 6e and 6f are schematic views of a process for performing inter-well penetration detection; wherein fig. 6a is a relative position relation diagram of hole penetration detection, fig. 6b is a hole penetration detection diagram of a position point of a coal seam roof, fig. 6c is a hole penetration detection diagram of a position point of a coal seam middle position point, fig. 6d is a hole penetration detection diagram of a position point of a coal seam bottom plate, fig. 6e is a hole penetration detection diagram of all point positions, and fig. 6f is a hole penetration detection alternating process diagram.
Wherein 1 is a state before the pressure relief of the coal seam; 2 is stress distribution before the pressure relief of the coal seam; the method comprises the steps of 3, taking a measure hole, 4, taking an inner protective layer, 5, taking a state after pressure relief of a coal seam, 6, taking a stress distribution after pressure relief of the coal seam, 7, taking a coal seam roof, 8, taking a rectangular unit, 9, taking a rectangular unit edge, 10, taking a pressure relief blank area, 11, taking a bottom plate rock roadway as 12, taking a transmitting probe pipe as 13, taking a receiving probe pipe as 14, taking a cable as 15, taking a detecting host as 16, and taking field intensity rays as 17.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, modifications, equivalents, improvements, etc., which are apparent to those skilled in the art without the benefit of this disclosure, are intended to be included within the scope of this invention.
As shown in fig. 1, this embodiment discloses a method for evaluating the construction effect of a protective layer in a coal seam, which includes the following steps:
s1, measuring the original gas content, the original gas pressure, the average thickness of a coal bed and the firmness coefficients of different layers of the coal bed of a single outburst coal bed by using a through-layer drilling method;
wherein the determination of the coal's firmness coefficient is based on the determination of the coal and petrophysical mechanical properties method section 12: the method for measuring the firmness coefficient of coal (GB/T23561.12-2010).
S2, arranging a plurality of groups of investigation holes in a coal seam floor rock roadway towards the coal seam, implementing different-scale coal unloading measures on each group of investigation holes, accurately measuring the coal unloading quantity of each investigation hole, and measuring the expansion deformation quantity of coal bodies around the investigation holes;
s3, determining an effective control range corresponding to the investigation holes based on the fact that the expansion deformation of the coal body around the investigation holes is more than or equal to 3 per mill, separating the coal layer from the inner protection layer by combining the arrangement characteristics of the coal layer mining working face and the succession requirements, and determining the coal unloading indexes of the inner protection layer, the measure holes and the measure hole units;
s4, implementing coal unloading measures according to unit coal unloading indexes of the measure holes, and accurately measuring the coal unloading amount of each measure hole; when the coal discharge amount of the measure hole is larger than or equal to the unit coal discharge index, the measure hole finishes the coal discharge measure, and when the coal discharge amount of the measure hole is smaller than the unit coal discharge index, the measure hole continues to execute the coal discharge measure;
s5, calculating accumulated coal unloading quantity of the measure holes, and judging whether the effectiveness of the measure meets the standard; if the standard is reached, step S6 is carried out; if the coal discharge amount does not reach the unit coal discharge index, repeating the step S4, namely continuously implementing coal discharge measures between adjacent measure holes of which the coal discharge amount does not reach the unit coal discharge index;
s6, after the coal unloading measures are implemented, dividing a measure hole control area into rectangular units with the diameter of 30m multiplied by 30m, and detecting whether a pressure relief blank area exists in a coal bed in the rectangular units by adopting a hole pit penetration detection method;
s7, judging the protection effect of the protective layer in the coal layer; if the pressure relief blank area does not exist, judging that the protection effect of the protective layer in the coal layer reaches the standard, and performing step S8; if the pressure relief blank area exists, judging that the protection effect of the protective layer in the coal layer does not reach the standard, repeating the step S4, and continuing to implement coal unloading measures in the pressure relief blank area;
s8, checking the effect of the inner protective layer measures, and after all drilling pressures are in a non-negative pressure state within the test range, measuring the drilling gas pressure and the gas content according to a program, wherein the measurement result meets the related requirements of the rules of preventing and treating coal and gas outburst.
As shown in fig. 2a, fig. 2b, fig. 3a, and fig. 3b, the coal unloading step S2 adopts hydraulic or mechanical power to destroy the integrity of the coal seam, and the crushed coal is unloaded from the measure hole 3, so as to form an inner protective layer 4 in the coal seam, that is, a plurality of independent or partially independent holes (the inner protective layer 4 in fig. 3 a) orthogonal or oblique to the coal seam are formed around the coal unloading measure hole 3, so as to provide horizontal expansion deformation space for the residual coal body of the coal seam, or form continuous holes (the inner protective layer 4 in fig. 2 a) parallel to the coal seam, so as to provide vertical expansion deformation space for the residual coal body of the coal seam, so that the crushed coal body is gradually creep-deformed, the occurrence form is changed from the state 1 before the pressure relief of the coal seam into the state 5 after the pressure relief of the coal seam, and the stress distribution 2 synchronously decreases and tends to be uniform before the pressure relief of the coal seam, and finally the stress distribution 6 after the pressure relief of the coal seam is formed.
As shown in fig. 4, in step S3, the measure holes 3 are arranged in the bottom plate rock roadway 12 according to the requirement of coal seam gas management, and the measure holes 3 are arranged in a plurality of rows of penetrating holes which are perpendicular to the roadway center line and are distributed in a fan shape, the measure holes 3 are required to penetrate through the coal seam roof 7 to be not less than 0.5m, and the maximum distance between adjacent measure holes is required to be not more than 2 times of the effective control range of the corresponding unit coal unloading index, and the control blank area is ensured not to exist between the adjacent measure holes; in step S6, the rectangular unit 9 divides the coal seam 8 into a 30m×30m rectangle according to the control area of the measure hole 3, wherein the plane of the edge of the rectangular unit 9 where the measure hole 3 is located is the rectangular unit edge 10, and a pressure relief blank area 11 may exist in the control area of the measure hole 3.
As shown in fig. 5, in the method of detecting penetration between holes in step S6, the device for detecting penetration between holes includes a transmitting probe tube 13, a receiving probe tube 14, a cable 15, and a detecting host 16, wherein 1 transmitting probe tube 13 is connected to the detecting host 16 through the cable 15 and is sent into the measuring hole 3, and simultaneously, a plurality of receiving probe tubes 14 are respectively connected to the respective detecting host 16 through corresponding cables 15 and are sequentially sent into the corresponding measuring holes 3. Then, fixed-point method detection, fixed-point transmission and multi-point reception are implemented: the high-frequency radio wave signals are sequentially transmitted by the transmitting probe tubes 13 at the positions of the coal seam roof, the coal seam middle and the coal seam floor, the high-frequency radio wave signals are sequentially and synchronously received by the receiving probe tubes 14 in fan shapes at corresponding positions, and the propagation and receiving paths of the high-frequency radio wave signals are the field intensity rays 17.
As shown in fig. 6, in the inter-hole penetration detection implementation step S6, the measure hole 3 in the edge 10 of one rectangular unit is used as the first measure channel, and the measure hole 3 in the edge 10 of the other rectangular unit of the rectangular unit 9, which is parallel to the first measure channel, is used as the second measure channel. According to the connection mode of the hole penetration detection device shown in fig. 4, the transmitting probe tube 13 and the receiving probe tube 14 are respectively connected with the corresponding cable 15 and the detection host 16 in sequence, the transmitting probe tube 13 is sent into the first measure hole 3 in the first measure channel, and the plurality of receiving probe tubes 14 are respectively sent into each measure hole 3 in the second measure channel.
The method comprises the steps that a high-frequency radio wave signal is sequentially transmitted at the positions of a coal seam roof, a coal seam middle and a coal seam bottom plate in a first measure hole 3 in a first measuring channel by a transmitting probe tube 13, and the high-frequency radio wave signal is sequentially and synchronously fan-shaped received at corresponding positions by a plurality of receiving probe tubes 14 in a second measuring channel;
secondly, the emission probe 13 is withdrawn from the first measure hole 3 in the first measuring channel and is sent into the second measure hole 3 in the first measuring channel, and detection is carried out in the same sequence until the emission probe 13 is detected in each measure hole 3 in the first measuring channel;
the third step, alternate the positions of the transmitting probe tube 13 and the receiving probe tube 14 in the first and second measuring channels, repeat the construction sequence according to the first and second steps, sequentially transmit high-frequency radio wave signals in each measure hole 3 in the second measuring channel by the transmitting probe tube 13, sequentially and synchronously sector-receive the high-frequency radio wave signals in corresponding point positions in the first measuring channel by the receiving probe tube 14, and finally finish the detection of all the point positions;
fourthly, according to the detection results of all the points, the pressure relief blank area 11 inside the coal bed 8 in the rectangular unit 9 is encircled by the cross drawing. The inter-well penetration detection of each rectangular unit 9 is then completed in the same manner.
The investigation holes are arranged in the bottom plate rock roadway according to the investigation requirement, are arranged perpendicular to the roadway center line, are in fan-shaped distribution, penetrate through the coal seam roof by 1 or 1 row of multi-layer penetrating holes, penetrate through the coal seam roof by at least 0.5m, and are spaced by 20m to avoid cross influence;
coal unloading measures including, but not limited to, coal unloading measures including hydraulic punching, slotting, mechanical reaming with investigation holes; the integrity of the coal seam is destroyed by adopting hydraulic power or mechanical power, and the crushed coal body is inspected Kong Xiechu to form holes (inner protection layers) with a certain shape in the coal seam, so that the purpose of providing expansion deformation space for inspecting the residual coal body in the hole control area is achieved;
holes (inner protective layer) or continuous holes (inner protective layer) parallel to the coal seam, which are formed by continuously discharging layered coal bodies with smaller firmness coefficients in the coal seam (shown in figure 2); or irregular holes (inner protective layer) in the form of a plurality of independent or partially independent holes (shown in figure 3) which are orthogonal or oblique to the coal seam;
different scales, according to the quantity of the coal unloading quantity of one investigation hole, the divided coal unloading measures implement different intensities, and each investigation hole of the same group implements the coal unloading measures of the same scale; the coal unloading amount is the mass of coal body unloaded from the investigation hole after taking coal unloading measures by the investigation hole; measuring the expansion deformation, namely arranging a plurality of groups of horizon positioners in the range of 5m to 10m on two sides of the investigation hole in advance, wherein each group of horizon positioners are arranged at intervals of 1m along the central line of a bottom plate rock roadway, and respectively monitoring the horizon deformation of a coal seam roof, a coal seam bottom plate and different layering of the coal seam before and after the coal unloading measures are implemented on the investigation hole;
the effective control range is a range covered by a circle which takes the investigation hole as the center and takes the minimum distance from the position of the expansion deformation of the coal body around the investigation hole which is more than or equal to 3 per mill to the center of the investigation hole as the radius;
the measure holes are arranged in the bottom plate rock roadway according to the coal seam gas management requirement, are perpendicular to the roadway central line and are in fan-shaped distribution, the measure holes penetrate through the coal seam roof to be not less than 0.5m, the maximum distance between every two adjacent measure holes is not more than 2 times of the effective control range of the corresponding unit coal unloading index, and no control blank area exists between every two adjacent measure holes;
the unit coal unloading index is the minimum coal unloading amount of the unit coal hole section length of the measure hole, which accords with the design interval of the measure hole, and taking the invention as an example, the unit coal unloading index is 0.5t/m (coal hole section) when the coal section 1m of the measure hole is required to discharge coal.
The measure effectiveness judging formula is as follows:
C total (S) Not less than n.C, wherein C Total (S) Accumulating the coal unloading amount for the measure hole, wherein the unit is t; n is the number of measure holes; c is a unit coal unloading index, and the unit is t;
the calculation formula of the accumulated coal unloading amount is as follows:
C total (S) =C 1 +C 2 +C 3 +……+C n Wherein C 1 The coal unloading amount of the first measure hole is t; c (C) 2 The unit of the coal unloading amount is t; c (C) n The unit of the coal unloading amount of the nth measure hole is t.
The hole penetration detection method comprises the steps of utilizing the edge measure holes of the dividing rectangular units to detect by a fixed-point method, transmitting at fixed points and receiving at multiple points: the method comprises the steps that an emission probe and a receiving probe are respectively arranged on two measuring channels (a left side edge measuring hole and a right side edge measuring hole of a rectangular unit), high-frequency radio wave signals sent by the same point emission probe are received (fan-shaped receiving) by the receiving probe at a corresponding point of the other measuring channel, the positions of the emission probe and the receiving probe are alternately changed, and after all detection is carried out on a rectangular unit coal seam between two opposite measuring channels, a pressure relief blank area inside the rectangular unit coal seam is drawn in an intersection mode. And then the inter-well penetration detection of each rectangular unit is completed in the same manner.
The point positions of the transmitting probe tube and the receiving probe tube are the positions of a coal seam roof, the middle position of the coal seam and the position of a coal seam bottom plate, and in the hole penetration detection implementation process, the point positions of the transmitting probe tube and the receiving probe tube are consistent, namely, the transmitting probe tube and the receiving probe tube are positioned at the position of the coal seam roof or the position of the coal seam bottom plate at the same time.
The coal seam inner protective layer is used for providing expansion deformation space for the residual coal body of the same coal seam by implementing coal unloading measures in the coal seam after the exploitation of the contrast interlayer protective layers (an upper protective layer and a lower protective layer) to promote the expansion deformation of the protected layer and eliminate the power of protrusion of the coal seam, thereby achieving the purpose of eliminating the power of protrusion of the coal seam.
Claims (10)
1. A method for evaluating the construction effect of a protective layer in a coal seam is characterized by comprising the following steps of: the method comprises the following steps:
s1, measuring the original gas content, the original gas pressure, the average thickness of a coal bed and the firmness coefficients of different layers of the coal bed of a single outburst coal bed by using a through-layer drilling method;
s2, arranging a plurality of groups of investigation holes in a coal seam floor rock roadway towards the coal seam, implementing different-scale coal unloading measures on each group of investigation holes, accurately measuring the coal unloading quantity of each investigation hole, and measuring the expansion deformation quantity of coal bodies around the investigation holes;
s3, determining an effective control range corresponding to the investigation holes based on the fact that the expansion deformation of the coal body around the investigation holes is more than or equal to 3 per mill, and determining a coal unloading index of a measure hole unit of the inner protective layer by combining the arrangement characteristics and the succession requirements of the coal mining working face, so as to design measure hole parameters;
s4, implementing coal unloading measures according to unit coal unloading indexes of the measure holes, and accurately measuring the coal unloading amount of each measure hole; when the coal discharge amount of the measure hole is larger than or equal to the unit coal discharge index, the measure hole finishes the coal discharge measure, and when the coal discharge amount of the measure hole is smaller than the unit coal discharge index, the measure hole continues to execute the coal discharge measure;
s5, calculating accumulated coal unloading quantity of the measure holes, and judging whether the effectiveness of the measure meets the standard; if the standard is reached, step S6 is carried out; if the coal discharge amount does not reach the unit coal discharge index, repeating the step S4, namely continuously implementing coal discharge measures between adjacent measure holes of which the coal discharge amount does not reach the unit coal discharge index;
s6, after the coal unloading measures are implemented, dividing a measure hole control area into rectangular units with the diameter of 30m multiplied by 30m, and detecting whether a pressure relief blank area exists in a coal bed in the rectangular units by adopting a hole pit penetration detection method;
s7, judging the protection effect of the protective layer in the coal layer; if the pressure relief blank area does not exist, judging that the protection effect of the protective layer in the coal layer reaches the standard, and performing step S8; if the pressure relief blank area exists, judging that the protection effect of the protective layer in the coal layer does not reach the standard, repeating the step S4, and continuing to implement coal unloading measures in the pressure relief blank area;
s8, checking the effect of the inner protective layer measures, and after all drilling pressures are in a non-negative pressure state within the test range, measuring the drilling gas pressure and the gas content according to a program, wherein the measurement result meets the related requirements of the rules of preventing and treating coal and gas outburst.
2. The method for evaluating the construction effect of the protective layer in the coal seam according to claim 1, wherein: the investigation holes are 1 or 1 row of a plurality of layer penetrating holes which are arranged in the bottom plate rock roadway according to the investigation requirement and are perpendicular to the roadway center line and distributed in a fan shape, the final positions of the investigation holes penetrate through the coal seam top plate to be not less than 0.5m, and the intervals of each group of investigation holes are 20m so as to avoid cross influence.
3. The method for evaluating the construction effect of the protective layer in the coal seam according to claim 1, wherein: coal unloading measures of investigation holes or measure holes, including but not limited to coal unloading measures utilizing hydraulic punching, slotting, mechanical reaming; the integrity of the coal seam is destroyed by adopting hydraulic power or mechanical power, and broken coal bodies are formed into holes with a certain shape, namely an inner protection layer, in the coal seam by investigation holes or measures Kong Xiechu, so that the purpose of providing expansion deformation space for the residual coal bodies in the investigation holes or measure hole control area is achieved.
4. A method for evaluating the construction effect of a protective layer in a coal seam as claimed in claim 3, wherein: the inner protective layer or the continuous holes parallel to the coal bed are formed after the layered coal bodies with smaller firmness coefficients in the coal bed are continuously discharged; or in the form of a plurality of independent or partially independent holes orthogonal or diagonal to the coal seam.
5. The method for evaluating the construction effect of the protective layer in the coal seam according to claim 1, wherein: and S2, measuring the expansion deformation amount, namely, arranging a plurality of groups of horizon positioners in the range of 5m to 10m on two sides of the investigation hole in advance, wherein each group of horizon positioners are arranged at intervals of 1m along the center line of the bottom plate rock roadway, and respectively monitoring the horizon deformation amounts of the coal seam top plate, the coal seam bottom plate and the coal seam before and after the coal unloading measures are implemented on the investigation hole.
6. The method for evaluating the construction effect of the protective layer in the coal seam according to claim 1, wherein: the effective control range in step S3 is a range covered by a circle having a radius from a position at which the expansion deformation amount of the coal body around the inspected hole is 3% or more to the minimum distance from the inspected hole center, the circle being centered on the inspected hole.
7. The method for evaluating the construction effect of the protective layer in the coal seam according to claim 1, wherein: and S3, arranging a plurality of through-layer holes which are in fan-shaped distribution and perpendicular to the central line of the roadway in the bottom plate rock roadway according to the requirement of coal seam gas control, wherein the through-layer holes are arranged in the bottom plate rock roadway, the through-layer holes penetrate through the coal seam roof to be not less than 0.5m, the maximum distance between every two adjacent through-layer holes is not more than 2 times of the effective control range of the unit coal unloading index corresponding to the through-layer holes, and the control blank area is not arranged between every two adjacent through-layer holes.
8. The method for evaluating the construction effect of the protective layer in the coal seam according to claim 1, wherein: in the step S3, the unit coal unloading index accords with the minimum coal unloading amount of the unit coal hole section length of the measure hole, which is determined as the coal unloading amount of 0.5t for the 1m measure hole coal section, namely the unit coal unloading index is 0.5t/m.
9. The method for evaluating the construction effect of the protective layer in the coal seam according to claim 1, wherein: in step S5, the measure validity determination formula is:
C total (S) Not less than n.C, wherein C Total (S) Accumulating the coal unloading amount for the measure hole, wherein the unit is t;n is the number of measure holes; c is a unit coal unloading index, and the unit is t;
the calculation formula of the accumulated coal unloading amount is as follows:
C total (S) =C 1 +C 2 +C 3 +……+C n Wherein C 1 The coal unloading amount of the first measure hole is t; c (C) 2 The unit of the coal unloading amount is t; c (C) n The unit of the coal unloading amount of the nth measure hole is t.
10. The method for evaluating the construction effect of the protective layer in the coal seam according to claim 1, wherein: the hole penetration detection method comprises the steps of utilizing the edge measure holes of the dividing rectangular units to detect by a fixed-point method, transmitting at fixed points and receiving at multiple points: the method comprises the steps that a transmitting probe tube and a receiving probe tube are respectively arranged on two measuring channels, high-frequency radio wave signals emitted by the transmitting probe tube at the same point are received by the receiving probe tube at the corresponding point of the other measuring channel, the positions of the transmitting probe tube and the receiving probe tube are alternately changed, and after all the rectangular unit coal seams between the two opposite measuring channels are detected, the inner pressure relief blank areas of the rectangular unit coal seams are alternately painted; and then the inter-well penetration detection of each rectangular unit is completed in the same manner.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211470498.9A CN115717529B (en) | 2022-11-23 | 2022-11-23 | Method for evaluating construction effect of protective layer in coal seam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211470498.9A CN115717529B (en) | 2022-11-23 | 2022-11-23 | Method for evaluating construction effect of protective layer in coal seam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115717529A CN115717529A (en) | 2023-02-28 |
| CN115717529B true CN115717529B (en) | 2023-05-12 |
Family
ID=85256691
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211470498.9A Active CN115717529B (en) | 2022-11-23 | 2022-11-23 | Method for evaluating construction effect of protective layer in coal seam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115717529B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118327688A (en) * | 2024-04-25 | 2024-07-12 | 国能神东煤炭集团乌兰木伦煤矿 | Structure regulation and control method for preventing rock burst of surrounding rock of coal mine tunnel |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102797465B (en) * | 2012-09-10 | 2014-09-03 | 河南理工大学 | Underground ultra-thin virtual protection layer hydraulic coal mining method |
| CN104675426A (en) * | 2014-12-16 | 2015-06-03 | 中建城开建设集团有限公司 | Gas outburst prevention construction method suitable for unprotected single coal seam mining |
| CN104727795B (en) * | 2015-02-14 | 2018-06-05 | 河南理工大学 | The low very thin layering water jet exploitation anti-reflection method of permeability soft seam |
| CN112360460A (en) * | 2020-11-26 | 2021-02-12 | 山西潞安环保能源开发股份有限公司常村煤矿 | Method and system for conducting equal-thickness treatment on working face coal seam thickening zone and adjacent coal seam |
| CN112800576B (en) * | 2020-12-14 | 2023-05-09 | 重庆大学 | Dual pressure relief outburst elimination judging method for coal seam group exploitation |
| CN114396244B (en) * | 2021-12-21 | 2023-10-31 | 重庆大学 | Method for extracting gas by up-and-down combined permeability-increasing of deep coal seam group well |
-
2022
- 2022-11-23 CN CN202211470498.9A patent/CN115717529B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN115717529A (en) | 2023-02-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103728655B (en) | A kind of coal face shock hazard adopts front pre-evaluation method | |
| Cao et al. | Case study of seismic hazard assessment in underground coal mining using passive tomography | |
| CN108412547B (en) | Pressure-bearing fault activation water inrush multi-field information collaborative monitoring impending forecasting method and monitoring system | |
| CN109239768B (en) | Method for testing loosening ring and damage degree of blasting surrounding rock | |
| CN115717529B (en) | Method for evaluating construction effect of protective layer in coal seam | |
| CN103941295A (en) | Pavement bearing capacity detection device | |
| Wang et al. | A comparative study of delay time identification by vibration energy analysis in millisecond blasting | |
| CN104390537A (en) | Method for controlling damage of slope pre-splitting blasting digging based on blast vibration test | |
| CN111257953B (en) | Method for testing pressure relief effect of large-diameter drill hole in roadway impact dangerous area | |
| He et al. | Active velocity tomography for assessing rock burst hazards in a kilometer deep mine | |
| CN109798106A (en) | A kind of prediction technique and control measure of bump risk | |
| CN114718653A (en) | Mine dynamic disaster real-time monitoring and early warning method based on three comprehensive parameters | |
| Qiu et al. | Response law and indicator selection of seismic wave velocity for coal seam outburst risk. | |
| CN114412573A (en) | Mine well wall fracture monitoring and early warning system and method | |
| CN110376643B (en) | Micro-seismic effect data processing method for jet grouting pile diameter detection | |
| CN112377256B (en) | Impact danger large-diameter drilling hole inspection method based on microseism monitoring | |
| CN112377258B (en) | Method for evaluating mining influence degree between adjacent mining areas and mining working faces | |
| CN111173487B (en) | Monitoring method for regional hydraulic fracturing | |
| CN113914932B (en) | Method for identifying coal and gas outburst dangerous area by using vibration wave tomography | |
| CN111413735B (en) | Coal face rapid earthquake transmission chromatography method capable of simultaneously exciting multiple seismic sources | |
| CN112130206A (en) | Underground roadway full-space seismic detection system and detection method | |
| CN117663933A (en) | Construction method for dynamically adjusting drilling and blasting parameters of karst tunnel | |
| CN113216981A (en) | Method for relieving danger of rock burst of deep-buried roadway | |
| CN110410149A (en) | A kind of device and method of real-time automatic monitoring coal mine empty water regimen always | |
| CN105698853B (en) | The detection method of country rock Effect of Bolt-grouting Support during a kind of working face extraction |
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 |