CN111946343A - Method for solving hard top plate collapse problem through ground vertical hole composite jet fracturing - Google Patents
Method for solving hard top plate collapse problem through ground vertical hole composite jet fracturing Download PDFInfo
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- CN111946343A CN111946343A CN202010744634.3A CN202010744634A CN111946343A CN 111946343 A CN111946343 A CN 111946343A CN 202010744634 A CN202010744634 A CN 202010744634A CN 111946343 A CN111946343 A CN 111946343A
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- 238000000034 method Methods 0.000 title claims abstract description 14
- 239000002131 composite material Substances 0.000 title claims abstract description 9
- 238000005553 drilling Methods 0.000 claims abstract description 21
- 239000003245 coal Substances 0.000 claims abstract description 20
- 238000005520 cutting process Methods 0.000 claims abstract description 9
- 238000005065 mining Methods 0.000 claims abstract description 8
- 239000011435 rock Substances 0.000 claims description 26
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000002253 acid Substances 0.000 claims description 6
- 238000005260 corrosion Methods 0.000 claims description 4
- 230000007797 corrosion Effects 0.000 claims description 4
- 230000000737 periodic effect Effects 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 239000004568 cement Substances 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 208000010392 Bone Fractures Diseases 0.000 description 3
- 206010017076 Fracture Diseases 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 238000005488 sandblasting Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 208000006670 Multiple fractures Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/28—Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent
- E21B43/283—Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent in association with a fracturing process
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/18—Drilling by liquid or gas jets, with or without entrained pellets
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/20—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Remote Sensing (AREA)
- Drilling And Exploitation, And Mining Machines And Methods (AREA)
Abstract
A method for solving the problem that a hard roof is difficult to collapse by composite jet fracturing of a vertical hole in the ground belongs to the technical field of coal mining, and aims to solve the problems that a coal seam roof to be stoped is hard and difficult to collapse, the initial pressure and period pressure step are long, and the pressure during the collapse of the roof is strong, 1 well is arranged in the middle of roadways on two sides of a working face to be stoped at a distance of 10-50m from a cutting hole to solve the problem of the initial pressure step, and the problem of the period pressure step is solved by subsequently arranging a drilling hole from the cutting hole to the stope mining line direction by combining terrain and fracturing influence radius. After well drilling and completion, aiming at a high-hardness top plate of a collapse zone, a hydraulic jet acidizing and fracturing mode is adopted to solve the problems that the top plate is hard and is not easy to collapse and the collapse is strong in pressure during the collapse process.
Description
Technical Field
The invention belongs to the technical field of coal mining, and particularly relates to a method for solving the problem that a hard top plate is difficult to collapse by ground vertical hole composite jet fracturing.
Background
China has a wide range of coal resources, underground geological conditions are complex, and the coal seam with a hard top plate accounts for about 1/3 of national coal reserves. For a hard roof with a large mining height working face, if the suspended area of the roof behind a goaf reaches a certain limit, the roof collapses in a large area, so that underground hurricanes are easily caused, and serious hidden dangers are brought to mine safety production.
Disclosure of Invention
The invention provides a method for treating hard top plates to be difficult to collapse and reducing the incoming pressure strength of the top plates by weakening the overall strength of rock masses through a ground vertical hole composite acid fracturing technology, aiming at the problems that thick hard rock layers exist in the range of a collapse zone after coal seam recovery, the collapse step distance of the thick hard rock layers is large, and the incoming pressure in the collapse process is strong.
The invention adopts the following technical scheme:
a method for solving the problem that a hard top plate is difficult to collapse by ground vertical hole composite jet fracturing comprises the following steps:
first, the vertical well is arranged on the ground
Arranging a plurality of vertical holes in the middle of roadways on two sides of a working face to be stoped, wherein the vertical holes comprise a drilling hole I for solving the problems of long step of initial pressure and long step of pressure coming and a plurality of drilling holes for solving the problem of long step of periodic pressure coming, the drilling hole I is positioned at a position 10-50m away from a cutting hole, and the drilling holes are arranged along a stoping line at intervals of 200-300m from the drilling hole I;
second, determining the fracturing horizon
After the coal seam is recovered, the height of a caving zone is 4-5 times of the mining height;
third, surface drilling
Firstly, opening a final hole below the stable bedrock and cementing wells, secondly, opening the final hole above a target coal seam roof without exposing the coal seam, putting a production casing and cementing wells, and returning the well cementing cement to the upper part of the target layer by 200 m;
fourthly, hydraulic jet acidizing and fracturing
The mechanical property of the rock is reduced by chemical corrosion of the preposed acid to the rock, and the macroscopic and microscopic structure of the rock is transformed by the generation and the expansion of the hydraulic pressure crack, so that the mechanical property of the rock is reduced.
In the third step the production casing is N80 steel grade phi 139.7 mm.
The invention has the following beneficial effects:
according to the invention, (1) only one well is arranged near the cut hole and the hydraulic jet acidizing and fracturing are combined, so that the problems that a hard top plate is not easy to collapse and the initial pressure step is long in the coal recovery process are solved; (2) the problem of long periodic pressure step is solved by arranging the drilling holes from the cutting hole to the mining stopping line direction by combining the landform and the fracture influence radius.
The invention reduces the mechanical property of the rock through the chemical corrosion effect of the preposed acid on the rock; secondly, the macroscopic and microscopic structure of the rock mass is transformed through the generation and the expansion of the hydraulic pressure crack, and the mechanical property of the rock mass is reduced. The two act together to weaken the mechanical property of the rock mass, reduce the overall strength of the roof rock, cause the roof to collapse in time, reduce the incoming pressure strength of the roof, prevent the roof from breaking and collapsing in large areas suddenly and producing the stress concentration release phenomenon, eliminate the potential safety hazard.
The hydraulic jet fracturing has the advantages of strong pertinence and combined operation of sand blasting perforation and fracturing, and meanwhile, the hydraulic jet fracturing of the coiled tubing can fracture multiple target rock stratums in one string.
Hydraulic jet fracturing process: the target layer has strong pertinence, independent perforation is not needed, and perforation fracturing operation is completed by directly sand blasting fracturing.
Drawings
FIG. 1 is a schematic representation of the earth borehole deployment of the present invention.
FIG. 2 is a schematic diagram of a surface borehole wellbore configuration of the present invention;
wherein: 1-drilling a hole I; 2, drilling; 3-stopping production line; 4-cutting the eyes; 5-coal seam to be mined; 6-earth surface; 7-mesh coal seam.
Detailed Description
The invention is further explained with reference to the accompanying drawings.
In order to effectively solve the problem of strong mine pressure in the working face extraction process, the ground vertical hole fracturing target layer is a thick and hard rock layer within the range of a working face collapse zone. According to the modes of calculation of a theoretical calculation formula of the height of the caving zone, field actual measurement of the height of the caving zone, FLAC 3D software simulation and the like, if the exact caving height does not exist, the height of the caving zone after the coal seam is recovered can be simply estimated by 4-5 times of the recovery height. Meanwhile, the overall strength of the rock mass is weakened through the ground drilling composite acidizing fracturing technology, the roof caving step distance is reduced, the mine pressure display degree is reduced, and potential safety hazards are eliminated.
The method mainly comprises the following steps:
well spacing design: and arranging the ground vertical holes to the middle parts of the roadways on the two sides of the working face to be recovered according to the fracture crack development rule. If the problem of long step distance of the initial pressure is only needed to be solved, the vertical hole on the ground is close to the cutting hole, and the distance between the vertical hole and the cutting hole is about 10-50 m; if the problem of periodic pressure is needed to be solved, the subsequent drilling arrangement is carried out from the hole cutting direction to the mining stopping line direction by combining the terrain and the fracture influence radius.
Secondly, drilling on the ground: firstly, opening a final hole below the stable bedrock and cementing the hole; and secondly, opening the coal seam to be above the top plate of the target coal seam, in order to ensure the underground safety and not expose the coal seam, putting an N80 steel grade phi 139.7mm production casing and cementing the well, and returning the well cementing cement to the upper part of the target layer by 200 m. If the upper part of the target layer is provided with a goaf, nitrogen drilling is adopted to penetrate through the goaf during construction.
Third, acidizing and fracturing: the method is mainly embodied in two aspects: firstly, the mechanical property of the rock is reduced through the chemical corrosion effect of the preposed acid on the rock; secondly, the macroscopic and microscopic structure of the rock mass is transformed through the generation and the expansion of the hydraulic pressure crack, and the mechanical property of the rock mass is reduced. The two act together to weaken the mechanical property of the rock mass, reduce the overall strength of the roof rock, cause the roof to collapse in time, reduce the incoming pressure strength of the roof, prevent the roof from breaking and collapsing in large areas suddenly and producing the stress concentration release phenomenon, eliminate the potential safety hazard. And acidizing and fracturing by adopting earth acid.
Fourthly, hydraulic jet fracturing technology: the target layer has strong pertinence, independent perforation is not needed, and perforation fracturing operation is completed by directly sand blasting fracturing.
Claims (2)
1. A method for solving the problem that a hard top plate is difficult to collapse by ground vertical hole composite jet fracturing is characterized by comprising the following steps of: the method comprises the following steps:
first, the vertical well is arranged on the ground
Arranging a plurality of vertical holes in the middle of roadways on two sides of a working face to be stoped, wherein the vertical holes comprise a drilling hole I for solving the problems of long step of initial pressure and long step of pressure coming and a plurality of drilling holes for solving the problem of long step of periodic pressure coming, the drilling hole I is positioned at a position 10-50m away from a cutting hole, and the drilling holes are arranged along a stoping line at intervals of 200-300m from the drilling hole I;
second, determining the fracturing horizon
After the coal seam is recovered, the height of a caving zone is 4-5 times of the mining height;
third, surface drilling
Firstly, opening a final hole below the stable bedrock and cementing wells, secondly, opening the final hole above a target coal seam roof without exposing the coal seam, putting a production casing and cementing wells, and returning the well cementing cement to the upper part of the target layer by 200 m;
fourthly, hydraulic jet acidizing and fracturing
The mechanical property of the rock is reduced by chemical corrosion of the preposed acid to the rock, and the macroscopic and microscopic structure of the rock is transformed by the generation and the expansion of the hydraulic pressure crack, so that the mechanical property of the rock is reduced.
2. The method for solving the problem of hard roof caving by ground vertical hole composite jet fracturing as claimed in claim 1, wherein: in the third step the production casing is N80 steel grade phi 139.7 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010744634.3A CN111946343A (en) | 2020-07-29 | 2020-07-29 | Method for solving hard top plate collapse problem through ground vertical hole composite jet fracturing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010744634.3A CN111946343A (en) | 2020-07-29 | 2020-07-29 | Method for solving hard top plate collapse problem through ground vertical hole composite jet fracturing |
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| Publication Number | Publication Date |
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| CN111946343A true CN111946343A (en) | 2020-11-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010744634.3A Pending CN111946343A (en) | 2020-07-29 | 2020-07-29 | Method for solving hard top plate collapse problem through ground vertical hole composite jet fracturing |
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| CN (1) | CN111946343A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112682020A (en) * | 2021-02-03 | 2021-04-20 | 山西晋城无烟煤矿业集团有限责任公司 | Directional fracturing method for weakening hard top plate along working face |
| CN114294046A (en) * | 2021-12-31 | 2022-04-08 | 山西晋煤集团技术研究院有限责任公司 | Up-down three-dimensional extraction method for full-coverage well in coal mine area |
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- 2020-07-29 CN CN202010744634.3A patent/CN111946343A/en active Pending
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112682020A (en) * | 2021-02-03 | 2021-04-20 | 山西晋城无烟煤矿业集团有限责任公司 | Directional fracturing method for weakening hard top plate along working face |
| CN114294046A (en) * | 2021-12-31 | 2022-04-08 | 山西晋煤集团技术研究院有限责任公司 | Up-down three-dimensional extraction method for full-coverage well in coal mine area |
| CN114294046B (en) * | 2021-12-31 | 2024-01-26 | 山西晋煤集团技术研究院有限责任公司 | Coal mine area full-coverage underground three-dimensional extraction method |
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Application publication date: 20201117 |