A kind of anti-collapse hole method for sealing of complete opening depth sieve pipe of deep fractures drillingTechnical field
The invention belongs to mining technique field, in particular to a kind of anti-collapse hole envelope of the complete opening depth sieve pipe of deep fractures drillingHole method.
Background technique
Many mining areas domestic in recent years have entered the deep mining stage, and after entering deep by superficial part, geological structure becomesComplicated, weight stress increases, and a large amount of energy of accumulation in coal and rock, non-prominent mine changes to projecting mine, so that deep coal petrographyDestruction have more impact and emergentness, deep mash gas pumping drilling is easier to collapse, therefore deep gas drainage is badly in need of changeThe method for sealing of extraction borehole is to improve extracting result.
The more application of existing mash gas pumping drilling " a two stifled notes " hole packer carries out sealing of hole, and sealing of hole principle is to utilize noteStock pump, to the slip casting section slip casting among two capsules bag and two capsules bag, completes the closure of the entire sealing section of drilling by Grouting Pipe；Two capsules bag is all wrapped on drainage tube, carries out extraction to coal-bed gas using drainage tube.
In the deep mining stage, by " a three high disturbances " effect, the geomechanics environment of deep engineering country rock is sent out compared with superficial partGiven birth to great changes, deep fractures internal pressure increases compared with superficial part coal seam internal pressure, conversion from hard rock mine to soft rock mine,Phenomena such as gas permeability of coal seam becomes smaller makes drilling, and there is a phenomenon where collapse holes, and due to the effect of extraction negative pressure, drainage tube is easy to occurBlocking, will necessarily cause the decline of extraction concentration, extraction rate to be lower and extend the extraction period during extraction；Existing " twoA stifled note " hole packer sealed borehole length is distance of the drilling orifice to stress concentration region peak value, after the peak value of stress concentration regionDrilling is collapsed by the pressure inside coal seam, and the extraction negative pressure crushing of the drilling of collapsed portion during extraction is larger,Waste negative pressure energy.
Existing sealing of hole mode cannot complete opening depth extraction length to deep fractures mash gas pumping drilling carry out complete extraction,Especially deep fractures internal pressure increases the caused collapse hole that drills, extraction blockage, extraction concentration as caused by drilling collapse holePhenomena such as decline, extraction rate reduce and the pressure loss of extraction negative pressure, wastes negative pressure energy.
Summary of the invention
For existing " a two stifled notes " hole-sealing technology above problem existing for the deep mining stage, the present invention provides one kindThe anti-collapse hole method for sealing of complete opening depth sieve pipe of deep fractures drilling, through-hole is arranged on drainage tube, part drainage tube is transformedAt sieve pipe, so that it is still able to maintain channel after collapse hole unimpeded, improves extraction rate.
Method of the invention sequentially includes the following steps:
1, one end of drainage tube being connect with the front end of sieve pipe, the sieve pipe is equipped with equally distributed through-hole,And the end of sieve pipe is equipped with end socket or plug is closed；
2, the assembly of outer pouch, interior pouch and Grouting Pipe is constituted into hole packer on drainage tube；
3, after the completion of drilling is drilled, by the drainage tube with sieve pipe along entering in drilling, sealing of hole is carried out to drilling, and is madeSieve pipe end and the spacing of boring end are less than the spacing of extraction tube wall and the inner sidewall that drills；
4, after completing sealing of hole, slip casting is carried out by the slip casting section between the external pouch of Grouting Pipe and interior pouch, completes drillingIt blocks.
In the above method, the diameter of through-hole is 3~5mm；The gross area of whole through-holes is the 1~2 of drainage tube area of sectionTimes.
In the above method, after the completion of drilling, drainage tube is placed in drilling within half an hour, and the outer pouch of completion,The assembly of interior pouch and Grouting Pipe.
In the above method, sieve pipe is structure as a whole with drainage tube or sieve pipe and drainage tube are interspersed in the same PVCIt is attached in pipe；Guan Weiyi sections of sieve, or be made of multistage；When sieve pipe is made of multistage, adjacent two sections by wearingIt is inserted in the same pvc pipe and is attached；When being attached using pvc pipe, drainage tube and sieve pipe distinguish PVC-U special glueIt is adhesively fixed together with pvc pipe.
Sieve pipe is arranged in interior pouch front end in method of the invention, and the closure of sieve pipe end can prevent from entering to bore in sieve Guan ShunDuring hole, there is slack coal to enter in sieve pipe；Half an hour internal drilling after the completion of drilling is not easy to collapse, therefore within half an hourSealing of hole is carried out along drainage tube is entered；When drainage tube and sieve pipe occupy the space entirely to drill, even if borehole collapse, in extraction negative pressureUnder the action of extraction can also be normally carried out, will not occur due to borehole collapse and slack coal is caused to block drainage tube, moreover it is possible to is effectiveAvoid negative pressure that from capable of wasting；This method can prevent slack coal after borehole collapse from generating blocking to drainage tube, and it is negative effectively to increase extractionThe transmission length of pressure improves the extraction rate of gas extraction concentration and working face, shortens the extraction period.
Detailed description of the invention
Fig. 1 is complete opening depth sieve pipe hole sealing structure schematic diagram before borehole collapse in the embodiment of the present invention；
Fig. 2 is complete opening depth sieve pipe hole sealing structure schematic diagram after borehole collapse in the embodiment of the present invention；
In figure, 1, drainage tube, 2, outer pouch, 3, interior pouch, 4, sieve pipe, 5, drilling (mine drilling), 6, sieve pipe envelopeHead, 7, Grouting Pipe, 8, slip casting section.
Specific embodiment
When drainage tube is along entering to drill in the embodiment of the present invention, guarantee that drainage tube is straight and at the uniform velocity enters drilling.
After drainage tube is along drilling is entered in the embodiment of the present invention, sieve pipe front end is less than 50mm at a distance from foot of hole.
Drilling axis is parallel to the horizontal plane in the embodiment of the present invention.
Deep fractures of the invention refer to coal seam position away from earth's surface 800m or more.
Embodiment 1
One end of drainage tube is connect with the front end of sieve pipe, the sieve pipe is equipped with equally distributed through-hole, andAnd the end of sieve pipe is equipped with end socket or plug is closed；Wherein the diameter of through-hole is 3~5mm；Total face of whole through-holesProduct is 1~2 times of drainage tube area of section；
The assembly of outer pouch, interior pouch and Grouting Pipe is constituted into hole packer on drainage tube；
After the completion of drilling is drilled, drainage tube is placed in drilling within half an hour, and complete outer pouch, interior pouch andThe assembly of Grouting Pipe carries out sealing of hole to drilling, and sieve pipe end and the spacing of boring end is made to be less than extraction tube wall and boreThe spacing of hole inner sidewall；Wherein sieve pipe and drainage tube are same material integral structure；
After completing sealing of hole, slip casting is carried out by the slip casting section between the external pouch of Grouting Pipe and interior pouch, completes drilling envelopeIt is stifled；It is as shown in Figure 1 to complete the complete opening depth sieve pipe hole sealing structure after blocking；Drainage tube (1) insertion drilling (5) simultaneously passes through outer pouch(2) it is connect with interior pouch (3), drainage tube (1) front end with sieve pipe (4), sieve pipe (4) end is equipped with sieve channel closure (6), sieveNetwork management end socket (6) is close to drilling (5) end；Grouting Pipe (7) passes through outer pouch (2), and front end is fixed on interior pouch (3), outer pouchIt (2) is slip casting section (8) that part of the Grouting Pipe (7) in slip casting section (8) is equipped with grouting port between interior pouch (3)；
Structure after collapsing is as shown in Figure 2；After borehole collapse, extraction can be also normally carried out under the action of extraction negative pressure,It will not occur to cause slack coal to block drainage tube due to borehole collapse, effectively avoid negative pressure that from capable of wasting.
Embodiment 2
With embodiment 1, difference is method:
(1) gross area of whole through-holes is 1.5 times of drainage tube area of section；
(2) sieve pipe is interspersed in the same pvc pipe with drainage tube and is attached；Sieve pipe is made of multistage, and adjacent twoSection is attached by being interspersed in the same pvc pipe, and drainage tube and sieve pipe difference PVC-U special glue are Nian Jie with pvc pipe solidIt is scheduled on together.
Embodiment 3
With embodiment 1, difference is method:
(1) gross area of whole through-holes is 2 times of drainage tube area of section；
(2) sieve pipe is interspersed in the same pvc pipe with drainage tube and is attached；Guan Weiyi sections of sieve.