Combined well spacing method for ground vertical well and underground horizontal well

Abstract

The invention discloses a ground vertical shaft and underground horizontal well combined well spacing method which comprises the following steps: determining vertical shaft estimated fracturing information and horizontal well estimated fracturing information according to acquired fracturing construction information of surrounding mines; the width of the to-be-mined working face and the lateral mining-induced fracture range of the mined working face are obtained, vertical shaft construction information is determined according to the width of the to-be-mined working face, the lateral mining-induced fracture range and the vertical shaft estimated fracturing information, fracturing construction is conducted on the thick and hard roof based on the vertical shaft construction information, and the vertical shaft fracturing range is obtained; horizontal well construction information is determined according to the horizontal well estimated fracturing information and the vertical well fracturing range, and fracturing construction is conducted on the impact main control rock stratum based on the horizontal well construction information; the plurality of ground vertical shafts are divided into at least two vertical shaft groups which are arranged at intervals along the inclined direction of a to-be-mined working face; according to the combined well spacing method provided by the embodiment of the invention, all-directional fracturing pressure relief can be carried out on the thick and hard top plate of the super-long working face, and cooperative prevention and control on rock burst and mine earthquake disasters are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mine roof fracturing pressure relief method, and in particular to a combined well drilling method of ground vertical shaft and underground horizontal well. BACKGROUND

[0002] Thick and hard roof is one of the main disaster factors of rock burst and mine earthquake disaster, and the high strength and complete structure of the thick and hard roof lead to stress concentration caused by the formation of suspended roof in the low roof of the goaf, which is easy to cause rock burst, and the high roof forms a large range of space structure, which is easy to produce strong mine earthquake after instability. According to statistics, 80% of rock burst and mine earthquake disasters in most mining areas are related to the instability of thick and hard roof.

[0003] In the related art, the ground vertical shaft fracturing method has significant advantages in regional treatment, advanced treatment, and pre-ripping weakening of multi-layer thick and hard roof, and thus has been widely applied in the field of mine earthquake treatment. However, for the problem of rock burst and mine earthquake disaster of an ultra-long working face with a face width of 350m or more, the ground vertical shaft fracturing method in the related art is still difficult to solve. Therefore, the present application provides a combined well drilling method of ground vertical shaft and underground horizontal well. SUMMARY

[0004] The present application aims to at least partially solve one of the technical problems in the related art.

[0005] To this end, an embodiment of the present application provides a combined well drilling method of ground vertical shaft and underground horizontal well. The combined well drilling method of ground vertical shaft and underground horizontal well can achieve full pre-ripping of thick and hard roof of an ultra-long working face, reduce the blind area of fracturing, and realize the coordinated prevention and control of rock burst and mine earthquake disaster.

[0006] The combined well drilling method of ground vertical shaft and underground horizontal well according to the present application comprises:

[0007] The combined well drilling method of ground vertical shaft and underground horizontal well is suitable for pre-ripping of thick and hard roof of a target mine, and the target mine comprises a mined working face, a to-be-mined working face, and a roadway arranged on both sides of the to-be-mined working face. The thick and hard roof comprises an impact main control rock layer and a mine earthquake main control rock layer. The combined well drilling method comprises:

[0008] S1: determining vertical shaft estimated fracturing information and horizontal well estimated fracturing information for the thick and hard roof according to obtained fracturing construction information of surrounding mines;

[0009] S2: obtaining a to-be-mined working face width and a lateral mining crack range of the mined working face, determining vertical shaft construction information according to the to-be-mined working face width, the lateral mining crack range, and the vertical shaft estimated fracturing information, performing fracturing construction on the impact main control rock layer and the mine earthquake main control rock layer based on the vertical shaft construction information, and obtaining a vertical shaft fracturing range of the ground vertical shaft.

[0010] S3: determining horizontal well construction information according to the horizontal well estimated fracturing information and the shaft fracturing range, and performing fracturing construction on the impact master rock formation based on the horizontal well construction information, wherein the downhole horizontal well is arranged between the ground shaft and the roadway;

[0011] The horizontal well construction information includes the number of the ground shafts, and the number of the ground shafts is multiple, and the multiple ground shafts are divided into at least two shaft groups, and the at least two shaft groups are arranged at intervals along the tendency of the working face to be mined.

[0012] In some embodiments, the two adjacent shaft groups are a first shaft group and a second shaft group, respectively, the first shaft group includes multiple first shafts arranged at intervals along the strike of the working face to be mined, and the second shaft group includes multiple second shafts arranged at intervals along the strike of the working face to be mined.

[0013] A vertical plane parallel to the strike of the working face to be mined is defined as a reference plane, and the projections of the multiple first shafts on the reference plane and the projections of the multiple second shafts on the reference plane are arranged alternately.

[0014] In some embodiments, the interval between two adjacent first shafts is equal to the interval between two adjacent second shafts.

[0015] In some embodiments, the projections of the multiple first shafts and the multiple second shafts on the reference plane form multiple projection areas, and the multiple projection areas are uniformly arranged along the strike of the working face to be mined.

[0016] In some embodiments, the shaft estimated fracturing information includes an estimated width of a fracturing fracture network, the interval between two adjacent ground shafts, the estimated width of the fracturing fracture network, and the periodic breaking step distance of the thick and hard roof of the working face to be mined satisfy the following formula:

[0017] D = b + d

[0018] D is the interval between two adjacent ground shafts, b is the estimated width of the fracturing fracture network, and d is the periodic breaking step distance of the thick and hard roof of the working face to be mined.

[0019] In some embodiments, the number of the shaft groups is two.

[0020] In some embodiments, the two side roadways of the working face to be mined are auxiliary haulage roadway and rubber haulage roadway respectively, the auxiliary haulage roadway is closer to the mined working face than the rubber haulage roadway, the first shaft group is closer to the auxiliary haulage roadway than the second shaft group, and the shaft construction information further comprises a shaft inclination position of the working face to be mined, and the shaft inclination position is arranged in the following manner:

[0021] If the lateral mining fracture range does not extend to the thick and hard roof of the working face to be mined, the distance between the shaft axis of the first shaft and the right side of the auxiliary haulage roadway is equal to one third of the width of the working face to be mined, and the distance between the shaft axis of the second shaft and the right side of the rubber haulage roadway is equal to one third of the width of the working face to be mined; if the lateral mining fracture range extends to the thick and hard roof of the working face to be mined, the distance between the shaft axis of the first shaft and the right side of the auxiliary haulage roadway is greater than one third of the width of the working face to be mined, so that the shaft fracturing range and the mining fracture range are arranged at intervals.

[0022] In some embodiments, the two downhole horizontal wells are arranged in pairs, and the two downhole horizontal wells arranged in pairs are arranged close to the auxiliary haulage roadway and the rubber haulage roadway respectively.

[0023] In some embodiments, the horizontal well estimated fracturing information comprises a horizontal well estimated fracturing range, the horizontal well estimated fracturing range arranged close to the auxiliary haulage roadway has a first boundary and a second boundary arranged along the inclination of the working face to be mined, the first boundary is arranged on the side of the auxiliary haulage roadway close to the working face to be mined, the second boundary is arranged on the side of the auxiliary haulage roadway away from the working face to be mined, the distance between the first boundary and the right side of the auxiliary haulage roadway is six times the width of the auxiliary haulage roadway, and the distance between the second boundary and the left side of the auxiliary haulage roadway is twice the width of the auxiliary haulage roadway.

[0024] The horizontal well estimated fracturing range arranged close to the rubber haulage roadway has a third boundary and a fourth boundary arranged along the inclination of the working face to be mined, the third boundary is arranged on the side of the rubber haulage roadway close to the working face to be mined, the fourth boundary is arranged on the side of the rubber haulage roadway away from the working face to be mined, the distance between the third boundary and the right side of the rubber haulage roadway is six times the width of the rubber haulage roadway, and the distance between the fourth boundary and the left side of the rubber haulage roadway is equal to the width of the rubber haulage roadway.

[0025] The ground shaft and underground horizontal well combined well arrangement method of the embodiment of the present application can improve the coverage range of the ground shaft crack network in the working face direction, and is more suitable for pre-splitting pressure relief of an ultra-long working face (a face width is greater than or equal to 350 m); meanwhile, the underground horizontal well is used for pre-splitting treatment in the key anti-burst area of the thick and hard roof of the working face near the two side roadways, so that the horizontal well fracturing crack network expands in the impact main control rock stratum; thus, the ground shaft and underground horizontal well combined well arrangement method can realize full-range and sufficient pre-splitting of the thick and hard roof of the ultra-long working face, reduce the pressure relief blind area, and realize cooperative prevention and control of rock burst and mine earthquake disasters BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a plane schematic view of the ground shaft and underground horizontal well combined well arrangement method of an embodiment of the present application.

[0027] Figure 2 is a sectional view of the ground shaft and underground horizontal well combined well arrangement method of an embodiment of the present application.

[0028] REFERENCE NUMERALS:

[0029] 1, a mined working face;

[0030] 2, a working face to be mined;

[0031] 3, an auxiliary transportation roadway;

[0032] 4, a gel transportation roadway;

[0033] 5, a ground shaft; 51, a shaft fracturing range; 52, a first shaft; 53, a second shaft; 54, a shaft fracturing point;

[0034] 6, an underground horizontal well; 61, a horizontal well fracturing point; 62, a horizontal well estimated fracturing range; 621, a first boundary; 622, a second boundary; 623, a third boundary; 624, a fourth boundary. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary, and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0036] As Figure 1 and Figure 2As shown, the ground shaft and underground horizontal well combined well arrangement method of the embodiment of the present application is suitable for pre-splitting of a thick and hard roof of a target mine, the target mine includes a mined working face 1, a to-be-mined working face 2, and a roadway arranged on both sides of the to-be-mined working face 2, the thick and hard roof includes an impact main control rock stratum and a mine shock main control rock stratum, and the combined well arrangement method includes:

[0037] S1: determining the shaft pre-splitting information and the horizontal well pre-splitting information for the thick and hard roof according to the obtained fracturing construction information of the surrounding mines;

[0038] S2: obtaining the width of the to-be-mined working face and the lateral mining crack range of the mined working face 1, determining the shaft construction information according to the width of the to-be-mined working face, the lateral mining crack range, and the shaft pre-splitting information, performing fracturing construction on the impact main control rock stratum and the mine shock main control rock stratum based on the shaft construction information, and obtaining a shaft fracturing range 51 of the ground shaft 5;

[0039] S3: determining the horizontal well construction information according to the horizontal well pre-splitting information and the shaft fracturing range 51, performing fracturing construction on the impact main control rock stratum based on the horizontal well construction information, and arranging an underground horizontal well 6 between the ground shaft 5 and the roadway;

[0040] The shaft construction information includes the number of the ground shaft 5, the number of the ground shaft 5 is multiple, the multiple ground shafts 5 are divided into at least two shaft groups, and the at least two shaft groups are arranged along the inclination of the to-be-mined working face 2.

[0041] It is known that due to the limited fracturing coverage range of the ground shaft 5, a fracturing blind area is easily formed at the edge of the shaft fracturing coverage range (i.e., the area close to the roadway on both sides of the to-be-mined working face 2), which causes insufficient pressure relief of the low roof (i.e., the impact main control rock stratum) of the to-be-mined working face 2 close to the roadway on both sides, and it is difficult to completely eliminate the risk of rock burst of the low roof.

[0042] The ground shaft and underground horizontal well combined well arrangement method of the embodiment of the present application uses the ground shaft 5 to perform pre-splitting treatment on the impact main control rock stratum and the mine shock main control rock stratum in the middle of the to-be-mined working face 2, and at least two shaft groups are arranged along the inclination of the to-be-mined working face 2, which can improve the coverage range of the fracture network of the ground shaft 5 in the inclination of the to-be-mined working face 2, and is more suitable for pre-splitting pressure relief of an ultra-long working face (the face width is greater than or equal to 350 m); at the same time, the underground horizontal well 6 is used to perform pre-splitting treatment on the key rock burst prevention area of the thick and hard roof of the to-be-mined working face 2 close to the roadway on both sides, so that the horizontal well fracture network expands in the impact main control rock stratum; thus, the combined well arrangement method of the ground shaft 5 and the underground horizontal well 6 can realize full and sufficient pre-splitting of the thick and hard roof of the ultra-long working face, reduce the fracturing blind area, and realize the coordinated prevention and control of rock burst and mine shock disaster.

[0043] Specifically, as shown in Figure 1As shown, the target mine includes multiple super-long working faces with a face width ≥ 350m, the super-long working face that has been mined is the mined working face 1, the super-long working face that has not been mined is the to-be-mined working face 2, and the to-be-mined working face 2 and the mined working face 1 have a coal pillar; the strike of the to-be-mined working face 2 is the coal mining advancing direction, and the inclination of the to-be-mined working face 2 is perpendicular to the strike thereof. The combined well arrangement method of the embodiment of the present application is suitable for pre-splitting the thick and hard roof of the to-be-mined working face 2, and reducing the risk of rock burst and mine earthquake disasters during the mining of the to-be-mined working face 2.

[0044] The roadway located on the side of the to-be-mined working face 2 close to the mined working face 1 is the auxiliary transport roadway 3, and the roadway located on the side of the to-be-mined working face 2 away from the mined working face 1 is the rubber transport roadway 4, the widths of the auxiliary transport roadway 3 and the rubber transport roadway 4 are equal; the side wall of the auxiliary transport roadway 3 close to the to-be-mined working face 2 is the main side wall thereof, the side wall of the auxiliary transport roadway 3 away from the to-be-mined working face 2 is the auxiliary side wall thereof, the side wall of the rubber transport roadway 4 close to the to-be-mined working face 2 is the main side wall thereof, and the side wall of the rubber transport roadway 4 away from the to-be-mined working face 2 is the auxiliary side wall thereof.

[0045] As shown in FIG. 1, Figure 2 As shown, the thick and hard roof includes multiple rock layers from bottom to top, first, the calculated fracture zone height is determined in a manner combining theoretical calculation and field measurement, the roof with a large thickness, good integrity and high strength below the fracture zone height range is the rock layer mainly controlling impact, and the thickness of the rock layer mainly controlling impact is generally not less than 10m; the roof with a large thickness, good integrity and high strength above the fracture zone height range is the rock layer mainly controlling mine earthquake, and the thickness of the rock layer mainly controlling mine earthquake is generally not less than 30m. The ground vertical well 3 vertically penetrates the rock layer mainly controlling mine earthquake and the rock layer mainly controlling impact, and the underground horizontal well 4 is arranged in the rock layer mainly controlling impact and extends along the strike of the to-be-mined working face 2.

[0046] Optionally, step S1 includes: determining the vertical well pre-estimation fracturing information for the target mine according to the obtained vertical well fracturing construction information of the surrounding mines, and determining the horizontal well pre-estimation fracturing information for the target mine according to the obtained horizontal well fracturing construction information of the surrounding mines.

[0047] It can be understood that the geological conditions of the surrounding mines are similar to the geological conditions of the target mine.

[0048] According to the vertical well fracturing construction information of the surrounding mines with similar geological conditions, the expansion of the vertical well fracture network under the preset fracturing pressure and the preset fracturing flow rate of the target mine can be estimated, and the vertical well pre-estimation fracturing information such as the pre-estimation width of the fracture network and the pre-estimation length of the fracture network is determined; then, the construction position and the construction interval of the ground vertical well 5 and other parameters are determined by the construction personnel, which provides a basis for determining the vertical well construction information, thereby ensuring that the vertical well fracturing range 51 can cover the thick and hard roof of the to-be-mined working face 2 in a large area, and improving the pre-splitting effect.

[0049] Meanwhile, according to the horizontal well fracturing construction information of the surrounding mines, the expansion of the horizontal well 6 fracture network under the target mine under the preset fracturing pressure and the preset fracturing flow can be estimated, the horizontal muscle estimated fracturing range and other horizontal well estimated fracturing information are determined, and then the construction position, spacing and other parameters of the horizontal well 6 under the well are determined by the construction personnel, which provides a basis for determining the horizontal well construction information, so as to use the horizontal well 6 fracturing construction to pre-split the key anti-scouring area of the top of the two side roadways, and reduce the blind area of fracturing.

[0050] It is known that the mined-out working face 1 is a working face that has been mined out, and lateral mining-induced fractures will be generated in the lateral direction of the mined-out working face. Alternatively, in step S2, the lateral mining-induced fracture range of the mined-out working face 1 can be estimated according to the rock movement angle, or detected by means such as geophysical prospecting, and then the lateral mining-induced fracture range of the mined-out working face is determined.

[0051] Alternatively, in step S2, the ground vertical well 5 fracture network expansion is monitored by using ground microseismic monitoring means, and then the vertical well fracturing range 51 is determined to provide a basis for the horizontal well construction information in step S3, and to fully ensure the fracturing pressure relief effect.

[0052] Alternatively, the fracturing construction steps of the ground vertical well 5 and the underground horizontal well 6 in steps S2 and S3 are: first, drilling construction is performed by using a drilling machine, and then fracturing construction is performed by using a fracturing pump truck; wherein the ground vertical well 5 is constructed downward from the ground surface to form the ground vertical well 5, and the underground horizontal well 6 is constructed upward from the inclined roadway 4 and the auxiliary roadway 3 to form the underground horizontal well 6.

[0053] Alternatively, as shown in Figure 2 When the fracturing construction of the ground vertical well 5 is performed, first, a perforating process is used to form two vertical well fracturing points 54 in the lowermost rock layer, the two vertical well fracturing points 54 form a group, the distance between the two vertical well fracturing points 54 in the same group is 18m-25m, and the preferred distance is 20m; a vertical well fracturing section is formed between the two vertical well fracturing points 54 in the same group, water fracturing is performed on the two vertical well fracturing points 54 in the group, and then a bridge plug process is used to block the vertical well fracturing section, that is, the vertical well fracturing construction for the lowermost rock layer is completed. Then, the same way is used to sequentially perform vertical well fracturing on multiple rock layers from bottom to top, so that the vertical well fracture network is distributed in the impact control rock layer and the mine shock control rock layer.

[0054] When the fracturing operation of the downhole horizontal well 4 is performed, first, the perforation technology is used to form two horizontal well fracturing points 61 at the end of the downhole horizontal well 6 away from the wellhead thereof, the two horizontal well fracturing points 61 form a group, the distance between the two horizontal well fracturing points 61 in the same group is 18m-25m, and preferably 20m; a horizontal well fracturing section is formed between the two horizontal well fracturing points 61 in the same group, the water injection fracturing is performed on the group of horizontal fracturing points 61, and then the bridge plug technology is used to block the horizontal well fracturing section, that is, the fracturing operation of the section of the horizontal well is completed; and then the same operation mode is used to sequentially perform the operation of multiple horizontal well fracturing sections in the direction close to the wellhead, so that the fracturing operation of the impact main control rock stratum is realized, the blind area of the fracturing operation is reduced, and the risk of the rock pressure of the low roof is reduced.

[0055] In some embodiments, as shown in Figure 1 two groups of vertical shafts are respectively a first group of vertical shafts 52 and a second group of vertical shafts 53, the first group of vertical shafts 52 includes a plurality of first vertical shafts 52 arranged at intervals along the strike of the working face 2 to be mined, and the second group of vertical shafts 53 includes a plurality of second vertical shafts 53 arranged at intervals along the strike of the working face 2 to be mined, a vertical plane parallel to the strike of the working face 2 to be mined is defined as a reference plane, and the projections of the plurality of first vertical shafts 52 on the reference plane and the projections of the plurality of second vertical shafts 53 on the reference plane are arranged alternately.

[0056] Through the above arrangement, the plurality of first vertical shafts 52 of the first group of vertical shafts 52 and the plurality of second vertical shafts 53 of the second group of vertical shafts 53 are arranged in a staggered three-flower shape, the fracture network formed by the first vertical shafts 52 and the fracture network formed by the second vertical shafts 53 are arranged in a staggered manner, the number of ground vertical shafts 5 can be reduced while ensuring the coverage range of the fracture network on the top of the working face 2 to be mined, in other words, the pre-fracturing effect can be ensured while reducing the construction cost.

[0057] It can be understood that the reference plane is vertically arranged and parallel to the strike of the working face 2 to be mined.

[0058] Optionally, in step S3, the thick and hard roof of the working face 2 to be mined is fractured based on the vertical shaft construction information to form the ground vertical shaft 5; when the two groups of vertical shafts are constructed, an interval alternating construction method is used.

[0059] In some embodiments, as shown in Figure 1 the distance between the two adjacent first vertical shafts 52 is equal to the distance between the two adjacent second vertical shafts 53.

[0060] In some embodiments, as shown in Figure 2 the projections of the plurality of first vertical shafts 52 and the plurality of second vertical shafts 53 on the reference plane form a plurality of projection areas, and the plurality of projection areas are uniformly arranged along the strike of the working face 2 to be mined.

[0061] Specifically, the projection of the first vertical shaft 52 on the vertical plane forms a first projection area, and the projection of the second vertical shaft 53 on the vertical plane forms a second projection area. Multiple first projection areas and multiple second projection areas are arranged alternately along the direction of the working face 2 to be mined, and the spacing between the first projection area and two adjacent second projection areas is equal. In other words, the line connecting the first vertical shaft 52 and the two adjacent second vertical shafts 53 forms an isosceles triangle. This can further improve the uniformity of the distribution of the first vertical shaft 52 and the second vertical shaft 53 at the top of the working face 2 to be mined, thereby improving the uniformity of the distribution of the hydraulic fracturing network, enhancing the pre-fracture effect, and ensuring the prevention and control of rock burst and mine earthquake disasters.

[0062] In some embodiments, the estimated fracturing information of the vertical shaft includes the estimated width of the fracture network. The distance between two adjacent ground vertical shafts 5, the estimated width of the fracture network, and the periodic fracture step distance of the thick hard roof of the working face 2 to be mined satisfy the following formula:

[0063] D=b+d

[0064] D is the distance between two adjacent ground shafts 5, b is the estimated width of the fracture network, and d is the periodic fracture step distance of the thick hard roof of the working face 2 to be mined.

[0065] Through the above arrangement, it can be ensured that the multiple staggered first vertical shafts 52 and second vertical shafts 53 fully cover the thick hard roof of the working face 2 to be mined along the direction of the working face 2 to be mined, thereby achieving a better pre-cracking effect.

[0066] Optionally, the periodic breaking step distance of the thick hard roof of the working face 2 to be mined is obtained according to the limit breaking step distance formula.

[0067] like Figure 1 As shown, the estimated width b of the fracture network of the ground shaft 5 is the dimension of the fracture network of the ground shaft 5 along the direction of the working face 2 to be mined, and the estimated length L of the fracture network is the dimension of the fracture network of the ground shaft 5 along the inclination of the working face 2 to be mined.

[0068] In some embodiments, the number of vertical shaft groups is two.

[0069] In this embodiment of the present invention, by staggering the two shaft groups, it is possible to ensure that the hydraulic fracturing network of the surface shaft 5 fully covers the thick, hard roof of the working face 2 to be mined. In other embodiments, when the width of the extra-long working face reaches a certain value, more than two shaft groups may be provided to ensure that the hydraulic fracturing network of the surface shaft 5 fully covers the thick, hard roof of the working face 2 to be mined.

[0070] In some embodiments, the tunnels on both sides of the working face 2 to be mined are the auxiliary transport tunnel 3 and the rubber transport tunnel 4. The auxiliary transport tunnel 3 is closer to the mined working face 1 than the rubber transport tunnel 4. The first vertical shaft 52 is closer to the auxiliary transport tunnel 3 than the second vertical shaft 53. The vertical shaft construction information also includes the inclination position of the vertical shaft in the direction of the working face 2 to be mined. The arrangement of the vertical shaft inclination position is as follows:

[0071] If the lateral mining cracks do not extend to the thick hard roof of the working face 2 to be mined, the distance between the shaft of the first vertical shaft 52 and the front wall of the auxiliary transport roadway 3 is equal to one-third of the width of the working face to be mined, and the distance between the shaft of the second vertical shaft 53 and the front wall of the rubber transport roadway 4 is equal to one-third of the width of the working face to be mined;

[0072] If the lateral mining fracture range extends to the thick hard roof of the working face 2 to be mined, the distance between the shaft axis of the first vertical shaft 52 and the main wall of the auxiliary transport tunnel 3 is greater than one-third of the width of the working face to be mined, so that the vertical shaft fracturing range 51 and the mining fracture range are arranged at intervals.

[0073] It is known that if the vertical shaft fracturing range 51 intersects with the mining fracture range, it will cause leakage, making the fracturing effect of the ground vertical shaft 5 worse.

[0074] If the lateral mining cracks do not extend to the top of the working face 2 to be mined, the first vertical shaft 52 group and the second vertical shaft 53 group divide the working face 2 to be mined into three equal parts along the inclination thereof, that is, the distance between the shaft of the first vertical shaft 52 and the main wall of the auxiliary transport roadway 3 is equal to one-third of the width of the working face to be mined, and the distance between the shaft of the second vertical shaft 53 and the main wall of the rubber transport roadway 4 is equal to one-third of the width of the working face to be mined (e.g. Figure 1 Thus, it can be ensured that the fracture network of the ground shaft 5 can cover the thick hard roof of the working face 2 to be mined in all directions, thereby improving the fracturing effect.

[0075] If the range of the lateral mining cracks extends to the top of the working face 2 to be mined, the first vertical shaft 52 group and the second vertical shaft 53 group need to be moved away from the mined working face 1, that is, the distance between the shaft axis of the first vertical shaft 52 and the front side of the auxiliary transport tunnel 3 is greater than one-third of the width of the working face to be mined; thereby, the vertical shaft fracturing range 51 formed by the fracturing construction of the ground vertical shaft 5 has a certain gap with the range of the lateral mining cracks, thereby ensuring the fracturing effect of the ground vertical shaft 5.

[0076] In some embodiments, as Figure 1 As shown, the underground horizontal wells 6 are arranged in pairs, and the two underground horizontal wells 6 arranged in pairs are respectively arranged close to the auxiliary transport tunnel 3 and the rubber transport tunnel 4.

[0077] By setting up two underground horizontal wells 6, the key prevention and control areas at the top of the auxiliary transport tunnel 3 and the rubber transport tunnel 4 can be fractured at the same time to prevent the occurrence of fracturing blind areas and ensure the anti-bumping effect.

[0078] Optionally, the length of the downhole horizontal well 6 is 500m to 800m. When the strike length of the working face 2 to be mined is greater than the length of the downhole horizontal well 6, multiple downhole horizontal wells 6 can be set along the strike length of the working face 2 to be mined, ensuring that the fracturing network of the downhole horizontal wells 6 can fully cover the extension direction of the auxiliary transport roadway 3 and the rubber transport roadway 4, achieving all-round pre-fracture of the key prevention and control area at the top of the roadway.

[0079] In some embodiments, as Figure 1 As shown, the estimated fracturing information of the horizontal well includes an estimated fracturing range 62 of the horizontal well. The estimated fracturing range 62 of the horizontal well arranged near the auxiliary transportation roadway 3 has a first boundary 621 and a second boundary 622 arranged along the inclination of the working face 2 to be mined. The first boundary 621 is arranged on the side of the auxiliary transportation roadway 3 close to the working face 2 to be mined, and the second boundary 622 is arranged on the side of the auxiliary transportation roadway 3 away from the working face 2 to be mined. The distance D1 between the first boundary 621 and the main side of the auxiliary transportation roadway 3 is six times the width of the auxiliary transportation roadway 3, and the distance D2 between the second boundary 622 and the secondary side of the auxiliary transportation roadway 3 is twice the width of the auxiliary transportation roadway 3.

[0080] The estimated fracturing range 62 of the horizontal well arranged near the rubber transport tunnel 4 has a third boundary 623 and a fourth boundary 624 arranged along the inclination of the working face 2 to be mined. The third boundary 623 is arranged on the side of the rubber transport tunnel 4 close to the working face 2 to be mined, and the fourth boundary 624 is arranged on the side of the rubber transport tunnel 4 away from the working face 2 to be mined. The distance D3 between the third boundary 623 and the main side of the rubber transport tunnel 4 is six times the width of the rubber transport tunnel 4, and the distance D4 between the fourth boundary 624 and the secondary side of the rubber transport tunnel 4 is equal to the width of the rubber transport tunnel 4.

[0081] Since the top area of ​​the tunnel is the key prevention and control area for rock burst, the prevention and control areas (i.e., pre-cracking areas) of the main wall of auxiliary tunnel 3, the secondary wall of auxiliary tunnel 3, the main wall of rubber-cut tunnel 4, and the secondary wall of rubber-cut tunnel 4 can be determined according to the distribution range of the tunnel surrounding rock stress concentration area and the tunnel roof cutting and unloading requirements. In addition, since auxiliary tunnel 3 is an air-facing tunnel, it is affected by the lateral hanging roof of the mined working face 1, and the degree of stress concentration of the surrounding rock of auxiliary tunnel 3 is greater than that of rubber-cut tunnel 4. Therefore, the prevention and control area of ​​the secondary wall of auxiliary tunnel 3 is larger than that of the secondary wall of rubber-cut tunnel 4.

[0082] By imposing the above restrictions on the range of horizontal well fracturing, the prevention and control area requirements of the auxiliary transport tunnel 3 main wall, auxiliary transport tunnel 3 secondary wall, rubber transport tunnel 4 main wall and rubber transport tunnel 4 secondary wall can be met, thereby fully pre-cracking the low-lying thick and hard roof near the tunnel area and reducing the risk of rock burst and mine earthquake disasters.

[0083] Optionally, if a single horizontal well cannot fracture the above-mentioned area, the number of downhole horizontal wells 6 can be increased, in other words, the downhole horizontal wells 6 at the top of the auxiliary haulage roadway 3 or the rubber haulage roadway 4 can be arranged in multiple numbers along the tendency of the working face 2 to be mined, and the shaft axes of the multiple downhole horizontal wells 6 are arranged in parallel.

[0084] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0085] In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" and "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0086] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or can be integrated; can be mechanical connection, can also be electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0087] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0088] In this disclosure, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present disclosure. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the terminology "comprising" is used in the disclosure as comprising but not limited to, that is, it is open-ended and does not exclude the presence of additional features, structures, materials, or characteristics.

[0089] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above-described embodiments are exemplary, and are not to be interpreted as limiting the present disclosure, and the ordinary skilled in the art can make changes, modifications, replacements, and variations to the above-described embodiments within the scope of the present disclosure.

Claims

1. A method for combining surface vertical wells and underground horizontal wells, characterized in that: The method is applicable to pre-splitting thick hard roof of a target mine, wherein the target mine includes a mined working face, a working face to be mined, and tunnels located on both sides of the working face to be mined. The thick hard roof includes rock strata mainly controlled by impact and rock strata mainly controlled by mine seismic. The combined well layout method includes: S1: Determining estimated fracturing information for the vertical shaft and the horizontal well for the thick hard roof based on the acquired fracturing construction information of surrounding mines; S2: Obtaining the width of the working face to be mined and the range of lateral mining-induced fissures of the mined working face, determining shaft construction information based on the width of the working face to be mined, the range of lateral mining-induced fissures, and the estimated fracturing information of the shaft, performing fracturing construction on the impact-maintaining rock formation and the mine-seismic-maintaining rock formation based on the shaft construction information, and obtaining the shaft fracturing range of the ground shaft; S3: determining horizontal well construction information according to the estimated fracturing information of the horizontal well and the fracturing range of the vertical well, and performing fracturing construction on the impact main control rock formation based on the horizontal well construction information, wherein the underground horizontal well is located between the ground vertical well and the roadway; The vertical shaft construction information includes the number of the ground vertical shafts. There are multiple ground vertical shafts, and the multiple ground vertical shafts are divided into at least two vertical shaft groups. At least two vertical shaft groups are arranged at intervals along the inclination of the working face to be mined.

2. The combined well layout method of surface vertical wells and underground horizontal wells according to claim 1 is characterized in that: The two adjacent vertical shaft groups are respectively a first vertical shaft group and a second vertical shaft group, the first vertical shaft group includes a plurality of first vertical shafts arranged at intervals along the direction of the working face to be mined, and the second vertical shaft group includes a plurality of second vertical shafts arranged at intervals along the direction of the working face to be mined; A vertical plane parallel to the direction of the working face to be mined is defined as a reference plane, and projections of multiple first vertical shafts on the reference plane and projections of multiple second vertical shafts on the reference plane are arranged alternately in sequence.

3. The combined well layout method of surface vertical wells and underground horizontal wells according to claim 2 is characterized in that: The distance between two adjacent first vertical shafts is equal to the distance between two adjacent second vertical shafts.

4. The combined well layout method of surface vertical wells and underground horizontal wells according to claim 3 is characterized in that: The projections of the plurality of first vertical shafts and the plurality of second vertical shafts on the reference surface form a plurality of projection areas, and the plurality of projection areas are evenly arranged along the direction of the working face to be mined.

5. The combined well layout method of surface vertical wells and underground horizontal wells according to claim 3 is characterized in that: The estimated fracturing information of the vertical shaft includes the estimated width of the fracture network. The distance between two adjacent vertical shafts on the ground, the estimated width of the fracture network, and the periodic fracture step distance of the thick hard roof of the working face to be mined satisfy the following formula: D=b+d D is the distance between two adjacent ground shafts, b is the estimated width of the fracture network, and d is the periodic fracture step distance of the thick hard roof of the working face to be mined.

6. The combined well layout method of surface vertical wells and underground horizontal wells according to claim 2 is characterized in that: The number of the vertical shaft groups is two.

7. The combined well layout method of surface vertical wells and underground horizontal wells according to claim 6 is characterized in that: The tunnels located on both sides of the working face to be mined are auxiliary transport tunnels and rubber transport tunnels, respectively. The auxiliary transport tunnel is closer to the mined working face than the rubber transport tunnel. The first vertical shaft group is closer to the auxiliary transport tunnel than the second vertical shaft group. The vertical shaft construction information also includes the vertical shaft inclination position inclined to the working face to be mined. The arrangement of the vertical shaft inclination position is as follows: If the lateral mining cracks do not extend to the thick hard roof of the working face to be mined, the distance between the shaft axis of the first vertical shaft and the main wall of the auxiliary transport roadway is equal to one-third of the width of the working face to be mined, and the distance between the shaft axis of the second vertical shaft and the main wall of the rubber transport roadway is equal to one-third of the width of the working face to be mined; If the lateral mining crack range extends to the thick hard roof of the working face to be mined, the distance between the shaft axis of the first vertical shaft and the main wall of the auxiliary transport tunnel is greater than one-third of the width of the working face to be mined, so that the vertical shaft fracturing range and the mining crack range are arranged at intervals.

8. The combined well layout method of surface vertical wells and underground horizontal wells according to claim 7 is characterized in that: The underground horizontal wells are arranged in pairs, and the two underground horizontal wells arranged in pairs are respectively arranged close to the auxiliary transport lane and the rubber transport lane.

9. The combined well layout method of surface vertical wells and underground horizontal wells according to claim 8, characterized in that: The estimated fracturing information of the horizontal well includes an estimated fracturing range of the horizontal well. The estimated fracturing range of the horizontal well arranged near the auxiliary transportation roadway has a first boundary and a second boundary arranged along the inclination of the working face to be mined. The first boundary is arranged on a side of the auxiliary transportation roadway close to the working face to be mined, and the second boundary is arranged on a side of the auxiliary transportation roadway away from the working face to be mined. The distance between the first boundary and the main side of the auxiliary transportation roadway is six times the width of the auxiliary transportation roadway, and the distance between the second boundary and the secondary side of the auxiliary transportation roadway is twice the width of the auxiliary transportation roadway. The estimated fracturing range of the horizontal well arranged close to the rubber transport tunnel has a third boundary and a fourth boundary arranged along the inclination of the working face to be mined. The third boundary is arranged on the side of the rubber transport tunnel close to the working face to be mined, and the fourth boundary is arranged on the side of the rubber transport tunnel away from the working face to be mined. The distance between the third boundary and the main side of the rubber transport tunnel is six times the width of the rubber transport tunnel, and the distance between the fourth boundary and the secondary side of the rubber transport tunnel is equal to the width of the rubber transport tunnel.

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