CN102536115B - Gas drainage borehole and construction method thereof - Google Patents

Abstract

The invention provides a gas drainage borehole and a construction method thereof. The gas drainage borehole comprises a first borehole and a second borehole. The first borehole is bored in a new stratum above a first coal seam roof and a bedrock section. The second borehole is bored between the first coal seam roof and a second coal seam roof below the first coal seam roof, and the diameter of the second borehole is larger than that of the first borehole. A first sleeve is disposed in the first borehole. A second sleeve is disposed in the first sleeve and above a first position above a bedrock face, a third sleeve is disposed in the first sleeve and between the lower side of the first position and a second position above the first coal seam roof, a fourth sleeve is connectedly arranged below the third sleeve, a fifth sleeve equal to the third sleeve in diameter and wall thickness is further disposed in the fourth sleeve, and a perforated pipe is connectedly arranged below the fifth sleeve and inside the second borehole. According to the technical scheme, the quality of the gas drainage borehole can be improved effectively, and gas yield is increased.

Description

Gas drainage borehole and construction method thereof

Technical field

The present invention relates to mine extraction technical field, relate in particular to a kind of gas drainage borehole and construction method thereof.

Background technology

Gas drainage borehole in existing colliery is the critical facility for the coal mine underground coal bed gas of extraction in mine.Therefore the quality of gas drainage borehole height directly determines gas drainage from coal seam effect.Therefore the structure of gas drainage borehole is extremely important.

By following the tracks of shaft bottom video recording monitoring, after coal mining, due to the displacement of sinking and producing of overlying rock after Seam Mining, cause mash gas extraction passage in the distortion of instrumentation tubes in gas drainage borehole or gas drainage borehole by shutoff, cause normally mash gas extraction.Therefore the quality of existing gas drainage borehole is not firm.

Summary of the invention

The invention provides a kind of gas drainage borehole and construction method thereof, in order to solve the illusive defect of the quality of gas drainage borehole in prior art, provide a kind of high-quality gas drainage borehole.

The invention provides a kind of gas drainage borehole, comprising: first boring of creeping in the new stratum more than the first roof and rock section; Between described the first roof and the second roof below described the first roof, be drilled with the second boring, the bore of described the second boring is greater than the bore of described the first boring;

In described the first boring, be provided with the first sleeve pipe; Above primary importance in described the first sleeve pipe, below bedrock surface, be provided with the second sleeve pipe, in described the first sleeve pipe, below described primary importance and be provided with the 3rd sleeve pipe between the second place above described the first roof; The external diameter of described the 3rd sleeve pipe equals the external diameter of described the second sleeve pipe, and the wall thickness of described the 3rd sleeve pipe is greater than the wall thickness of described the second sleeve pipe; The below of described the 3rd sleeve pipe is connected with Quadruplet pipe, and the internal diameter of described Quadruplet pipe is greater than the external diameter of described the 3rd sleeve pipe, is also provided with bore and wall thickness and equals respectively the bore of described the 3rd sleeve pipe and the 5th sleeve pipe of wall thickness in described Quadruplet pipe; Interior, described the 5th sleeve pipe below of described the second boring is connected with bore and wall thickness is equal to described the 3rd bore of sleeve pipe and the floral tube of wall thickness; Between described Quadruplet pipe and described the 5th sleeve pipe, be provided with platen sealing device;

Described primary importance is in the following 70m-90m of described bedrock surface; The described second place is in described the first roof top 8m-12m.

The construction method that the invention provides a kind of gas drainage borehole, comprising:

In new stratum more than the first roof and rock section, creep into the first boring;

In described the first boring, be lowered to the first sleeve pipe;

Utilize the first drill bit being lowered to by described the first sleeve pipe, between described the first roof and the second roof below described the first roof, creep into the second boring, the bore of described the second boring is greater than the bore of described the first boring;

According to described first boring of having bored and described the second boring, will estimate that the second sleeve pipe, the 3rd sleeve pipe, Quadruplet pipe, the 5th sleeve pipe that will be lowered to are connected in turn with floral tube; Wherein said the second sleeve pipe need to be lowered to and be positioned at the first sleeve pipe, primary importance below bedrock surface top; Described the 3rd sleeve pipe need to be lowered to below interior, the described primary importance of described the first sleeve pipe and between the second place above described the first roof; Described Quadruplet pipe is connected to the below of described the 3rd sleeve pipe; Described the 5th sleeve pipe need to be lowered to described Quadruplet pipe; Described floral tube need to be lowered in described the second boring, described the 5th sleeve pipe below; Described primary importance is in the following 70m-90m of described bedrock surface; The described second place is in described the first roof top 8m-12m;

Be lowered to described the second sleeve pipe connecting, described the 3rd sleeve pipe, described Quadruplet pipe, described the 5th sleeve pipe and described floral tube; And open the screw thread between described Quadruplet pipe and described the 5th sleeve pipe by rotating described the second sleeve pipe, make described the second sleeve pipe, described the 3rd sleeve pipe, described Quadruplet pipe, described the 5th sleeve pipe and described floral tube in each self-corresponding position, and the platen sealing device being arranged between described Quadruplet pipe and described the 5th sleeve pipe is pressed between described the 5th sleeve pipe and described the second sleeve pipe.

Gas drainage borehole of the present invention and construction method thereof, by being set, the second boring is greater than the first boring, after can avoiding mining, due to the sinking of rock stratum and the displacement of generation, cause the floral tube in the gas drainage borehole of down-hole be out of shape or stop up, and cause cannot mash gas extraction.Can be to the reserved certain outer annular space of floral tube; be used for cushioning or dodge rock stratum destruction to floral tube in shearing, extrusion process, thereby effectively protect floral tube, after mining influence; floral tube section can retain certain outlet passageway, can guarantee the integrity in gas hole.

And the wall thickness of the 3rd sleeve pipe arranging between the second place in the first sleeve pipe, below primary importance and above the first roof in technical scheme of the present invention is greater than the wall thickness of the second sleeve pipe arranging above the primary importance in the first sleeve pipe, below bedrock surface, thereby greatly increase the non-deformability of the sleeve pipe that is positioned at rock section.Therefore, adopt technical scheme of the present invention, can effectively improve the quality of gas drainage borehole, increase gas pumping amount.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is some embodiments of the present invention, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.

The structural representation of the gas drainage borehole that Fig. 1 provides for the invention process one.

The structural representation of the gas drainage borehole that Fig. 2 provides for the embodiment of the present invention two;

The flow chart of the construction method of the gas drainage borehole that Fig. 3 provides for the embodiment of the present invention three.

The specific embodiment

For making object, technical scheme and the advantage of the embodiment of the present invention clearer, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment in the present invention, those of ordinary skills, not making the every other embodiment obtaining under creative work prerequisite, belong to the scope of protection of the invention.

The structural representation of the gas drainage borehole that Fig. 1 provides for the invention process one.As shown in Figure 1, the gas drainage borehole of the present embodiment comprises: first boring 1 of creeping in the new stratum more than the first roof 13-1 coal and rock section; The bore that is drilled with the second boring 2, the second borings 2 between the first roof 13-1 coal and the second roof 11-2 coal below the first roof 13-1 coal is greater than the bore of the first boring 1;

In the first boring 1, be provided with the first sleeve pipe 3; In the first sleeve pipe 3, above the primary importance A of bedrock surface below 4, be provided with the second sleeve pipe 5, in the first sleeve pipe 3, below primary importance A and between the second place B above the first roof 13-1 coal, be provided with the3rd sleeve pipe 6; The external diameter of the3rd sleeve pipe 6 equals the external diameter of the second sleeve pipe 5, and the wall thickness of the3rd sleeve pipe 6 is greater than the wall thickness of the second sleeve pipe 5; The internal diameter that the below of the3rd sleeve pipe 6 is connected with Quadruplet pipe 7, the Quadruplet pipes 7 is greater than the external diameter of the3rd sleeve pipe 6, is also provided with bore and wall thickness and equals respectively the bore of the3rd sleeve pipe 6 and the5th sleeve pipe 8 of wall thickness in Quadruplet pipe 7; The second boring 2 is interior, the5th sleeve pipe 8 belows are connected with bore and wall thickness is all equal to the 3rd bore ofsleeve pipe 6 and the floral tube of wall thickness 9; Wherein primary importance A is in the following 70m-90m of bedrock surface 4; Second place B is in the first roof 13-1 coal top 8m-12m.

In the present embodiment, between Quadruplet pipe 7 and the5th sleeve pipe 8, be also provided with platen sealing device 11.This platen sealing device 11 specifically can comprise: be arranged on Quadruplet pipe 7 outsides, lower end annulus, be arranged on the annulus of the5th sleeve pipe 8 outsides, lower end and be wrapped in cotton around of the5th sleeve pipe 8 and the putty of smearing.Before going into the well, the upper end of the lower end of Quadruplet pipe 7 and the5th sleeve pipe 8 is by screwed connection, in lower going-into-well after, be positioned at second sleeve pipe 5 in aperture by backspin, open the screw thread between Quadruplet pipe 7 and the 5th sleeve pipe 8.Due to the self gravitation of the second sleeve pipe 5, the3rd sleeve pipe 6 and Quadruplet pipe 7, Quadruplet pipe 7 is moved downward and be enclosed within on the5th sleeve pipe 8, in the folding process of Quadruplet pipe 7, under the annulus of Quadruplet pipe 7 lower ends, push away cotton and the putty of the5th sleeve pipe 8 outsides, so that this cotton and putty are pressed between the annulus of Quadruplet pipe 7 lower ends and the annulus of the5th sleeve pipe 8 lower ends.The compression that this cotton and putty are subject to upper and lower annulus is able to the gap between compacting the5th sleeve pipe 8 and the first sleeve pipe 3, thereby by the inner side of the first sleeve pipe 3, region between the outside of the floral tube 9 of the second sleeve pipe 5, the3rd sleeve pipe 6 and Quadruplet pipe 7 and below is divided into two sections, thereby can prevent from leaking under epimere cement paste the circular hole that stops up the ventilation of the floral tube outside of hypomere to floral tube section.The external diameter of the annulus of the annulus of Quadruplet pipe 7 lower ends and the5th sleeve pipe 8 lower ends should be slightly less than the internal diameter of the first sleeve pipe 3, so that go into the well.The gas drainage borehole of the present embodiment and construction method thereof, by being set, the second boring is greater than the first boring, after can avoiding mining, due to the displacement of sinking and producing in coal seam, cause the floral tube in the gas drainage borehole of down-hole be out of shape or stop up, and cause cannot mash gas extraction.Can be to the reserved certain outer annular space of floral tube; be used for cushioning or dodge rock stratum destruction to floral tube in shearing, extrusion process, thereby effectively protect floral tube, after mining influence; floral tube section can retain certain outlet passageway, can guarantee the integrity in gas hole.And the wall thickness of the 3rd sleeve pipe arranging between the second place in the first sleeve pipe, below primary importance and above the first roof in the technical scheme of the present embodiment is greater than the wall thickness of the second sleeve pipe arranging above the primary importance in the first sleeve pipe, below bedrock surface, thereby greatly increase the non-deformability of the sleeve pipe that is positioned at rock section.Therefore, adopt the technical scheme of the present embodiment, can effectively improve the quality of gas drainage borehole.

The structural representation of the gas drainage borehole that Fig. 2 provides for the embodiment of the present invention two.As shown in Figure 2, for fear of impurity rubble from ground in the first sleeve pipe 3 is called in 9 sections of floral tubes in the second boring 2, gather methane gas thereby affect in floral tube 9.In the present embodiment, below the second boring 2, also creep into by the 3rd boring 10.The3rd boring 10 is mainly used in depositing the rock Su that floral tube section falls down, and bore need not be too large, and preferably, the aperture that can get the 3rd boring 10 is less than the aperture of the first sleeve pipe 3, and also the aperture of the 3rd boring 10 is also just less than the internal diameter of floral tube 9 particularly.Between the second seat earth 11-2 ' coal of the 3rd boring 10 in the second roof 11-2 coal and correspondence.

Adopt the technical scheme of the present embodiment, further strengthened the practicality of gas drainage borehole.

The aperture that it should be noted that the boring of first in above-described embodiment 1 can be 350mm; The aperture of the second boring 2 can be 420mm; The aperture of the 3rd boring 10 can be 133mm.In practical application, also can be set to other size, but should follow the principle of above-described embodiment.

And wherein the external diameter of the first sleeve pipe 3 can be that 273mm, wall thickness can be 10.16mm; The external diameter of the second sleeve pipe 5 can be that 177.8mm, wall thickness can be 9.19mm; The external diameter of the3rd sleeve pipe 6, the5th sleeve pipe 8, floral tube 9 can be respectively that 177.8mm, wall thickness can be 19.05mm; The outer warp of Quadruplet pipe 7 can be that 219mm, wall thickness can be 10mm.The external diameter of the annulus of the annulus of Quadruplet pipe 7 lower ends and the5th sleeve pipe 8 lower ends can be 235mm.The size of above-mentioned parts in actual applications, also can be set to other sizes according to the actual requirements.

The flow chart of the construction method of the gas drainage borehole that Fig. 3 provides for the embodiment of the present invention three.As shown in Figure 3, the construction method of the gas drainage borehole of the present embodiment, specifically can comprise:

In step 100, new stratum more than the first roof and rock section, creep into the first boring;

Step 101, in the first boring, be lowered to the first sleeve pipe;

The first drill bit that step 102, utilization are lowered to by the first sleeve pipe creeps into the second boring between the first roof and the second roof below the first roof, and bore of this second boring is greater than the bore of this first boring;

Particularly, first drill bit is here for drawing cave drill bit, and this first drill bit is owing to will getting out bore and be greater than the second boring of the first boring, thus this first drill bit can be can opening and closing pawl formula drill bit.In the time going into the well by the first sleeve pipe, can be altogether.Arrive construction location, can open so that creep into.

Step 103, according to second boring of having bored and the 3rd boring, will estimate that the second sleeve pipe, the 3rd sleeve pipe, Quadruplet pipe, the 5th sleeve pipe that will be lowered to are connected in turn with floral tube;

The position that can be lowered to according to each sleeve pipe by silk mouth particularly and order, connect each sleeve pipe in turn.When preparation before here going into the well, also need to be wound around cotton and smear greasy filth in the 5th jacket exterior.

Wherein the second sleeve pipe need to be lowered to and be positioned at the first sleeve pipe, primary importance below bedrock surface top; The 3rd sleeve pipe need to be lowered in the first sleeve pipe, below primary importance and between the second place above the first roof; Quadruplet pipe is connected to the below of described the 3rd sleeve pipe; The 5th sleeve pipe is arranged in Quadruplet pipe; Floral tube need to be lowered in the second boring, the 5th sleeve pipe below; Primary importance is in the following 70m-90m of bedrock surface; The second place is in the first roof top 8m-12m; In detail also can be with reference to the explanation of above-described embodiment one and accompanying drawing 1.

It should be noted that, as shown in above-described embodiment one, between Quadruplet pipe 7 and the5th sleeve pipe 8, be also provided with platen sealing device.This platen sealing device comprise be arranged on outside, Quadruplet pipe lower end annulus, be arranged on the annulus of the 5th outside, sleeve pipe lower end and be wrapped in cotton around of the 5th sleeve pipe and the putty of smearing.Before going into the well, cotton is wrapped in to the 5th jacket exterior, and smears putty in the 5th jacket exterior.The lower end of Quadruplet pipe is connected with the upper end of the 5th sleeve pipe.

Step 104, be lowered to the second sleeve pipe, the 3rd sleeve pipe, Quadruplet pipe, the 5th sleeve pipe and the floral tube that connect; And open the screw thread between Quadruplet pipe and the 5th sleeve pipe by rotating the second sleeve pipe, make the second sleeve pipe, the 3rd sleeve pipe, Quadruplet pipe, the 5th sleeve pipe and floral tube in each self-corresponding position, and the platen sealing device being arranged between Quadruplet pipe and the 5th sleeve pipe is pressed between the 5th sleeve pipe and the second sleeve pipe.

Wherein, in the present embodiment, the external diameter of the 3rd sleeve pipe equals the external diameter of the second sleeve pipe, and the wall thickness of the 3rd sleeve pipe is greater than the wall thickness of the second sleeve pipe.The bore of the 5th sleeve pipe and wall thickness equal respectively bore and the wall thickness of the 3rd sleeve pipe; The internal diameter of Quadruplet pipe is greater than the external diameter of the 3rd sleeve pipe; The bore of floral tube and wall thickness equal respectively bore and the wall thickness of the 3rd sleeve pipe.

After being lowered to the each sleeve pipe connecting, open the screw thread between Quadruplet pipe and the 5th sleeve pipe by rotating the second sleeve pipe.Due to the self gravitation of the second sleeve pipe, the 3rd sleeve pipe and Quadruplet pipe, Quadruplet pipe is moved downward and be enclosed within on the 5th sleeve pipe.In the folding process of Quadruplet pipe, under the annulus of Quadruplet pipe lower end, push away cotton and the putty of the 5th jacket exterior, so that this cotton and putty are pressed between the annulus of Quadruplet pipe lower end and the annulus of the 5th sleeve pipe lower end.The compression that this cotton and putty are subject to upper and lower annulus is able to the gap between compacting the 5th sleeve pipe and the first sleeve pipe, thereby in the inner side of the first sleeve pipe, fine and close waterstop of formation between the outside of the lower end of Quadruplet pipe, by the inner side of the first sleeve pipe, region between the outside of the floral tube of the second sleeve pipe, the 3rd sleeve pipe and Quadruplet pipe and below is divided into two sections, can prevent in the time of follow-up Cementing, cement paste infiltrates floral tube section in the time that high pressure is cemented the well, and prevents that the floral tube section of giving vent to anger from being sealed by cement paste.The external diameter of the annulus of the annulus of Quadruplet pipe lower end and the 5th sleeve pipe lower end should be slightly less than the internal diameter of the first sleeve pipe, so that go into the well.

Platen sealing device also has an important function, floral tube adopts screw thread and the underlying simultaneously after being connected of each sleeve pipe, after at the bottom of lower hand-hole, open the screw thread between Quadruplet pipe and the 5th sleeve pipe, Quadruplet pipe moves down, make Quadruplet pipe and the 5th sleeve pipe overlapping, change to bottom floral tube during on stratum, reserved the space of free activity.This method can, by floral tube and each sleeve pipe with at present, reduce drilling program one time, has also avoided connecting Quadruplet pipe simultaneously and has inserted and do not enter the 5th sleeve pipe and cased situation has again been saved time, man power and material greatly.

The construction method of the gas drainage borehole of the present embodiment, be greater than the first boring by digging into the second boring, after can avoiding mining, due to the sinking of rock stratum and the displacement of generation, cause and under gas drainage borehole in floral tube be out of shape or stopped up, and cause cannot mash gas extraction.Can be to the reserved certain outer annular space of floral tube; be used for cushioning or dodge rock stratum destruction to floral tube in shearing, extrusion process, thereby effectively protect floral tube, after mining influence; floral tube section can retain certain outlet passageway, can guarantee the integrity in gas hole.

And the wall thickness of the 3rd sleeve pipe arranging between the second place in the first sleeve pipe, below primary importance and above the first roof in the technical scheme of the present embodiment is greater than the wall thickness of the second sleeve pipe arranging above the primary importance in the first sleeve pipe, below bedrock surface, thereby greatly increase the non-deformability of the sleeve pipe that is positioned at rock section.Therefore, adopt the technical scheme of the present embodiment, can effectively improve the quality of gas drainage borehole.

It should be noted that, after step 102 in above-described embodiment, before step 103, also comprise: utilize the second drill bit being lowered to by the first sleeve pipe, between the second roof and corresponding seat earth, creep into the 3rd boring, the aperture of the 3rd boring is less than the internal diameter of the second sleeve pipe.

The bore of the 3rd boring that the second drill bit creeps into here particularly is just less than the internal diameter of each sleeve pipe of fashionable process under drill bit, and the 3rd drill bit can be set to arbitrary shape and the structure being convenient to creep into here.

It should be noted that, after the step 104 in above-described embodiment, also comprise: adopt Cementing technology to carry out totally-enclosed to the annular gap between second place top, the first outside of sleeve and the first boring.Can greatly shorten the well cementation time, improve cementing quality, also greatly strengthen the ability of sleeve pipe obstruct Cenozoic layer of sand water simultaneously.

Below take the aperture of the first boring as 350mm; The aperture of the second boring is 420mm; The aperture of the 3rd boring is 133mm; The external diameter of the first sleeve pipe is that 273mm, wall thickness are 10.16mm; The external diameter of the second sleeve pipe is that 177.8mm, wall thickness are 9.19mm; The external diameter of the 3rd sleeve pipe, the 5th sleeve pipe, floral tube is respectively 177.8mm, wall thickness is 19.05mm; The outer warp of Quadruplet pipe is that 219mm, wall thickness are that 10mm is example, describes the construction method of the extraction test drilling that adopts above-described embodiment in detail, and the sampling test boring shown in above-described embodiment is constructed, and concrete steps are as follows:

(1), start downwards the new stratum more than the first roof 13-1 coal and rock section, to creep into the first boring from ground, its aperture Φ is 350mm; In following description, all represent aperture with Φ.

(2) while proceeding to hole depth 683.02m by Φ 245mm bit drills, carry out conventional logging, determine that Φ is that 273 wall thickness are that the first sleeve pipe underlying position of 10.16mm is 663.00m (as the first coal top board 13-1 coal), then use the reaming of Φ 350mm drill bit to 672.82m, 0～662.98m underlying Φ, 273 × 10.16mm the first sleeve pipe, it is totally-enclosed that annular gap employing Cementing technology is carried out hanging type.Φ 245mm drill bit represents to creep into the drill bit that aperture Φ is 245mm.First set pipe body also can adopt petroleum casing pipe;

Particularly, be all lower seated position here, be to be all reference point take aperture, take the direction to downward-extension as the represented position of positive direction.

(3) first sleeve pipes admittedly manage qualified after, creep into 735.00m (as the second coal top board 11-2 coal top 10m) with Φ 245mm drill bit, use Φ 133mm drill bit instead and continue to creep into 760.34m (as the second coal seam floor 11-2 coal top 10m), whole hole.Well logging determine aperture Φ be the second sleeve pipe, aperture Φ that 177.8mm, wall thickness are 9.19mm be 177.8mm, wall thickness the 3rd sleeve pipe that is 19.05mm and floral tube to descend together seated position lowermost end be 740.00m (can above the second coal top board 11-2 coal 3m-5m position), then draw cave drill bit with Φ 420mm and carry out reaming.After Φ 420mm reaming finishes, underlying sleeve pipe, wherein 0～498.38m (80m left and right, bedrock surface 427.65m below) underlying the second sleeve pipe; 498.38m～653.08m (653.08m is that the first coal top board 13-1 coal is 10m left and right, 663m top) underlying the 3rd sleeve pipe, at the bottom of the 3rd sleeve pipe, the long aperture Φ of mouth connection 8.40m is 219mm, wall thickness is 10mm Quadruplet pipe.Quadruplet pipe underlying is at 653.08m～661.48m particularly.661.48～740.00m underlying aperture, down-hole Φ is 177.8mm, and wall thickness is 19.05mm floral tube, and the long Φ of floral tube connection suitable for reading 7.50m is that 177.8mm, wall thickness are 19.05mm the 5th sleeve pipe, and the 5th sleeve pipe is arranged in Quadruplet pipe, overlapping with Quadruplet pipe.

(4) solid Guan Houning qualified after, sweep the interior residual water mud of pipe and cover (flower) inside pipe wall mud skin with the punching of Φ 139mm Noncoring drill bit, rush the cleaning bottom of hole degree of depth and exceed the mouth degree of depth at the bottom of floral tube.Then be pressed into appropriate sodium pyrophosphate solution, soak 24 hours, rinse up and down floral tube with high-pressure spray, until clear water is returned in aperture, duration of well flushing is greater than 48 hours.

Through above operation, extraction test drilling just can come into operation.

Finally it should be noted that: above embodiment only, in order to technical scheme of the present invention to be described, is not intended to limit; Although the present invention is had been described in detail with reference to previous embodiment, those of ordinary skill in the art is to be understood that: its technical scheme that still can record aforementioned each embodiment is modified, or part technical characterictic is wherein equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution depart from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (10)

1. a gas drainage borehole, is characterized in that, comprising: first boring of creeping in the new stratum more than the first roof and rock section; Between described the first roof and the second roof below described the first roof, be drilled with the second boring, the bore of described the second boring is greater than the bore of described the first boring;

In described the first boring, be provided with the first sleeve pipe; Above primary importance in described the first sleeve pipe, below bedrock surface, be provided with the second sleeve pipe, in described the first sleeve pipe, described primary importance and be provided with the 3rd sleeve pipe between the second place above described the first roof; The external diameter of described the 3rd sleeve pipe equals the external diameter of described the second sleeve pipe, and the wall thickness of described the 3rd sleeve pipe is greater than the wall thickness of described the second sleeve pipe; The below of described the 3rd sleeve pipe is connected with Quadruplet pipe, and the internal diameter of described Quadruplet pipe is greater than the external diameter of described the 3rd sleeve pipe, is also provided with bore and wall thickness and equals respectively the bore of described the 3rd sleeve pipe and the 5th sleeve pipe of wall thickness in described Quadruplet pipe; Interior, described the 5th sleeve pipe below of described the second boring is connected with bore and wall thickness is equal to described the 3rd bore of sleeve pipe and the floral tube of wall thickness; Between described Quadruplet pipe and described the 5th sleeve pipe, be provided with platen sealing device;

Described primary importance is in the following 70m-90m of described bedrock surface; The described second place is in described the first roof top 8m-12m.

2. gas drainage borehole according to claim 1, is characterized in that, the 3rd boring has also been crept in described the second boring below, and the aperture of described the 3rd boring is less than the internal diameter of described the first sleeve pipe.

3. gas drainage borehole according to claim 2, is characterized in that:

Described the 3rd drill hole is between described the second roof and corresponding seat earth.

4. according to the arbitrary described gas drainage borehole of claim 2-3, it is characterized in that:

The aperture of described the first boring is 350mm;

And/or the aperture of described the second boring is 420mm;

And/or the aperture of described the 3rd boring is 133mm.

5. gas drainage borehole according to claim 3, is characterized in that:

The external diameter of described the first sleeve pipe is that 273mm, wall thickness are 10.16mm;

And/or the external diameter of described the second sleeve pipe is that 177.8mm, wall thickness are 9.19mm;

And/or the external diameter of described the 3rd sleeve pipe, described the 5th sleeve pipe, described floral tube is 177.8mm, wall thickness is 19.05mm;

And/or the external diameter of described Quadruplet pipe is that 219mm, wall thickness are 10mm.

6. a construction method for gas drainage borehole, is characterized in that, comprising:

In new stratum more than the first roof and rock section, creep into the first boring;

In described the first boring, be lowered to the first sleeve pipe;

Utilize the first drill bit being lowered to by described the first sleeve pipe, between described the first roof and the second roof below described the first roof, creep into the second boring, the bore of described the second boring is greater than the bore of described the first boring;

According to described first boring of having bored and described the second boring, will estimate that the second sleeve pipe, the 3rd sleeve pipe, Quadruplet pipe, the 5th sleeve pipe that will be lowered to are connected in turn with floral tube; Wherein said the second sleeve pipe need to be lowered to and be positioned at the first sleeve pipe, primary importance below bedrock surface top; Described the 3rd sleeve pipe need to be lowered in described the first sleeve pipe, described primary importance and between the second place above described the first roof; Described Quadruplet pipe is connected to the below of described the 3rd sleeve pipe; Described the 5th sleeve pipe need to be lowered to described Quadruplet pipe; Described floral tube need to be lowered in described the second boring, described the 5th sleeve pipe below; Described primary importance is in the following 70m-90m of described bedrock surface; The described second place is in described the first roof top 8m-12m;

Be lowered to described the second sleeve pipe connecting, described the 3rd sleeve pipe, described Quadruplet pipe, described the 5th sleeve pipe and described floral tube; And open the screw thread between described Quadruplet pipe and described the 5th sleeve pipe by rotating described the second sleeve pipe, make described the second sleeve pipe, described the 3rd sleeve pipe, described Quadruplet pipe, described the 5th sleeve pipe and described floral tube in each self-corresponding position, and the platen sealing device being arranged between described Quadruplet pipe and described the 5th sleeve pipe is pressed between described the 5th sleeve pipe and described the second sleeve pipe.

7. the construction method of gas drainage borehole according to claim 6, is characterized in that:

The external diameter of described the 3rd sleeve pipe equals the external diameter of described the second sleeve pipe, and the wall thickness of described the 3rd sleeve pipe is greater than the wall thickness of described the second sleeve pipe; The bore of described the 5th sleeve pipe and wall thickness equal respectively bore and the wall thickness of described the 3rd sleeve pipe; The internal diameter of described Quadruplet pipe is greater than the external diameter of described the 3rd sleeve pipe; The bore of described floral tube and wall thickness equal respectively bore and the wall thickness of described the 3rd sleeve pipe.

8. the construction method of gas drainage borehole according to claim 6, it is characterized in that: the drill bit that described utilization is lowered to by described the first sleeve pipe, after creeping into the second boring between described the first roof and the second roof below described the first roof, described according to described first boring of having bored and described the second boring, by the second sleeve pipe of estimating to be lowered to, the 3rd sleeve pipe, Quadruplet pipe, before the 5th sleeve pipe is connected with floral tube, also comprise: utilize the second drill bit being lowered to by described the first sleeve pipe, between described the second roof and corresponding seat earth, creep into the 3rd boring, the aperture of described the 3rd boring is less than the internal diameter of described the first sleeve pipe.

9. according to the construction method of the arbitrary described gas drainage borehole of claim 6-8, it is characterized in that:

After described the second sleeve pipe that the running connects, described the 3rd sleeve pipe, described Quadruplet pipe, described the 5th sleeve pipe and described floral tube and described platen sealing device, also comprise: adopt Cementing method to carry out totally-enclosed to the annular gap between described second place top, described the first outside of sleeve and described the first boring.

10. according to the construction method of the arbitrary described gas drainage borehole of claim 6-8, it is characterized in that: the aperture of described the first boring is 350mm;

And/or the aperture of described the second boring is 420mm;

And/or the aperture of described the 3rd boring is 133mm;

And/or the external diameter of described the first sleeve pipe is that 273mm, wall thickness are 10.16mm;

And/or the external diameter of described the second sleeve pipe is that 177.8mm, wall thickness are 9.19mm;

And/or the external diameter of described the 3rd sleeve pipe, described the 5th sleeve pipe, described floral tube is 177.8mm, wall thickness is 19.05mm;

And/or the external diameter of described Quadruplet pipe is that 219mm, wall thickness are 10mm.

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