Containing the high-order lane coal bed gas drainage method of shielding soft rock
Technical field
The invention belongs to Coal Mining Technology field.
Background technology
It is one of new problem of coal mining that coal and gas are adopted altogether.
Gas drainage under suction at present is mainly played common boring and is carried out this extraction in the service tunnel in this coal seam.In gas drainage under suction, along with mining depth increases, the effect of gas drainage under suction and strata structure and lithology closely related.For the coal bed gas drainage poor effect of soft rock top board, be mainly that the crack of incompetent bed is easily closed at present, have shielding action, also do not find effective gas drainage method containing the coal seam of soft rock.
Therefore for the gas drainage under suction under many structures, large buried depth, the soft condition in rock stratum, need to invent a kind of effective drainage method.
Summary of the invention
The object of the invention is, for the undesirable present situation of gas drainage under suction effect that contains at present shielding soft rock, to propose a kind of extraction construction method satisfactory for result.
Technical scheme of the present invention is:
Containing a high-order lane coal bed gas drainage method for shielding soft rock, step is as follows:
The first step: the high-order lane of constructing
Before seam mining, development work in the hard formation of roof, so because design is called for short high-order lane at top, coal seam, the tunnel of having opened up will ensure adjoining rock stability, strengthens temporary lining;
Second step: conventional drilling-draining
During working face mining, first in work plane service tunnel to coal bed drilling, tentatively draw out methane;
The 3rd step: in tentatively drawing out methane, to coal bed drilling, when boring, adopt the drilling rod of brill certainly of hollow structure in high-order lane, and at aperture in that section of processing that enters coal seam of drilling rod, pierce behind coal seam and will stay in coal bed drilling from boring drilling rod, proceed extraction by drilling rod certainly.
Be made up of hollow steel tube from the structure of boring drilling rod, one meter of one joint of length, adopts and is threaded between joint and joint, is connected with drill bit and bores upper some apertures on first segment.
Good effect of the present invention is:
1, due to extraction in high-order lane, meet the characteristic that gas upwards flows, institute is so that extraction.
2, utilize hollow and be with foraminate drilling rod extraction, not being afraid of containing shielding soft rock sealing boring, extraction is effective.
Brief description of the drawings
Below in conjunction with brief description of the drawings enforcement of the present invention.
Fig. 1 is high-order lane and conventional borehole pattern;
Fig. 2 be high-order lane borehole pattern '
Fig. 3 is from boring jackrod structure schematic diagram.
Detailed description of the invention
Containing a high-order lane coal bed gas drainage method for shielding soft rock, step is as follows:
The first step: the high-order lane of constructing
Before seam mining, development work in the hard formation of roof, so because design is called for short high-order lane at top, coal seam, the tunnel of having opened up will ensure adjoining rock stability, strengthens temporary lining, and high-order lane is arranged as shown in Figure 1;
Second step: conventional drilling-draining
During working face mining, first play conventional boring in work plane service Nei Xiang coal seam, tunnel, tentatively draw out methane, boring is arranged as shown in Figure 1;
The 3rd step: in tentatively drawing out methane, in the high-order lane of top board to coal bed drilling, when boring, adopt the drilling rod of brill certainly of hollow structure, and at aperture in that section of processing that enters coal seam of drilling rod, after piercing coal seam, will stay in coal bed drilling from boring drilling rod, proceed extraction by drilling rod certainly, boring is arranged as shown in Figure 2.
From the structure of boring drilling rod as shown in Figure 3, be mainly hollow steel tube composition, one meter of one joint of length, adopts and is threaded between joint and joint, is connected with also above some apertures of brill of drill bit on first segment.