CN108361010A - A kind of high gas layer " ten " font hydraulic fracturing anti-reflection method - Google Patents

Abstract

The invention discloses a kind of high gas layer " ten " font hydraulic fracturing anti-reflection methods, include the following steps：Two fracturing boreholes tilted upward of construction in each drill site in the lanes Di Chou, fracturing borehole end hole is set to be located in the middle part of coal seam thickness, " ten " font of constructing since fracturing borehole end hole drilling, the drilling of " ten " font is set to be completely in coal seam, hydraulic fracturing is carried out to each fracturing borehole, hydraulic fracturing process is divided into two stages, during hydraulic fracturing, coal body is under the action of high pressure water by pressure break, crisscross Fracture System is formed in coal body, sand enters with high pressure water in crack simultaneously, hinders the closure in crack, increases the gas permeability of coal body.The method of the present invention is scientific and reasonable, realizes the effective anti-reflection of high gas layer, and guarantee is provided for the efficient extraction of gas and Safety of Coal Mine Production.

Description

A "ten"-shaped hydraulic fracturing permeability enhancement method for high gassy coal seams

technical field

The invention relates to the technical field of coal seam anti-permeability, in particular to a "ten"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams.

Background technique

During the mining process of high gassy coal seams, gas dynamic disaster accidents such as coal and gas outburst are prone to occur, and gas exceeding the limit often occurs. In order to prevent accidents such as coal and gas outburst and gas exceeding the limit, drainage is usually carried out before high-gas coal seams are mined, but most of the coal seams are permeable coal seams, and conventional gas drainage methods cannot achieve efficient gas drainage. Drainage is difficult, and the extraction time is long, and the extraction effect is poor, which seriously affects the normal mining of coal mines, and it is difficult to achieve safe and efficient production of coal mines. In order to improve the gas drainage effect of high-gas coal seams and ensure the safe and efficient production of coal mines, effective measures must be taken to increase the gas permeability of coal seams.

Hydraulic fracturing is an effective method to increase the air permeability of coal seams. However, due to the large stress on deep coal seams, they are generally in a state of high stress. Under the action of high stress, it is very easy to close, resulting in poor fracturing effect, and cannot achieve effective permeability enhancement of high gassy coal seams.

Contents of the invention

The object of the present invention is to overcome the above-mentioned problems in the prior art, and provide a method for increasing gas permeability by "cross"-shaped hydraulic fracturing in high-gas coal seams.

In order to achieve the above-mentioned technical purpose and achieve the above-mentioned technical effect, the present invention is realized through the following technical solutions:

A "ten"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams, comprising the following steps:

a. There is a track uphill between the transportation uphill and the return air uphill. The track uphill is connected with the transportation alley through the parking lot. The return air uphill is connected with the return air alley parallel to the transportation alley. There is a cut-out hole connected between them, and the return air uphill is located at the connection with the bottom pumping roadway, and the bottom pumping roadway is excavated until it reaches the bottom of the cut-out hole;

b. After the construction of the bottom pumping roadway is completed, a drilling site will be constructed every 30-60m in the bottom pumping roadway, and two inclined upward fracturing drill holes will be constructed in each drilling site of the bottom pumping roadway. The diameter is 90-100mm, so that the final hole of the fracturing drilling is located in the middle of the coal seam thickness, and the "ten"-shaped drilling is constructed from the final hole of the fracturing drilling, so that the "ten"-shaped drilling is completely in the coal seam;

c. After the fracturing drilling and the "ten"-shaped drilling are completed, each fracturing drilling is sealed;

d. After the fracturing drilling is sealed, hydraulic fracturing is performed on each fracturing drilling. The hydraulic fracturing process is divided into two stages. The first stage is the conventional hydraulic fracturing stage, which refers to the use of conventional hydraulic fracturing The stage of fracturing the coal seam; the second stage is the sandy hydraulic fracturing stage, which means that in the process of hydraulic fracturing, the coal body is fractured under the action of high-pressure water, so that the pores and fissures in the coal body continue to develop, Expansion, forming a criss-cross fracture system in the coal body, and at the same time, sand enters the fractures with high-pressure water, which produces a supporting effect on the fractures, thereby hindering the closure of the fractures and increasing the gas permeability of the coal body; the conventional hydraulic fracturing stage ends 24 Hours later, the sandy hydraulic fracturing stage is carried out;

e. 48 hours after the fracturing of each fracturing hole, the hydraulic fracturing of the next fracturing hole is carried out until the hydraulic fracturing of the last fracturing hole is completed.

Preferably, in the "ten"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams, a drilling site is constructed every 50m in the bottom pumping roadway.

Preferably, in the "ten"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams, the angle between two fracturing boreholes located in the same drilling site is 30-90°.

Preferably, in the "ten"-shaped hydraulic fracturing anti-permeability method for the high-gas coal seam, the "ten"-shaped drill hole is 50m long and 94mm in diameter.

Preferably, in the above-mentioned "ten"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams, after the fracturing drilling is completed, the holes are sealed with Jiumina filling material.

Preferably, in the "ten"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams, the fracturing drilling is sealed to the bottom of the coal seam.

The beneficial effects of the present invention are:

The "ten"-shaped hydraulic fracturing method for high-gas coal seams provided by the present invention is scientific and reasonable, and the hydraulic fracturing process is divided into two stages, in which the sand-containing hydraulic fracturing stage can hinder the closure of cracks and realize the effective maintenance of high-gas coal seams. Enhanced penetration provides a guarantee for efficient gas drainage and safe production of coal mines.

Of course, any product implementing the present invention does not necessarily need to achieve all the above-mentioned advantages at the same time.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that are required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a schematic sectional view of Fig. 1 along plane A-A;

Fig. 3 is a schematic cross-sectional view of Fig. 2 along the B-B plane;

In the accompanying drawings, the list of parts represented by each label is as follows:

1-Transport uphill, 2-Track uphill, 3-Return wind uphill, 4-Transport level roadway, 5-Bottom pumping roadway, 6-Return air level roadway, 7-Fracturing drilling, 8-Cutting hole, 9- Coal seam, 10-"ten"-shaped drilling.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Embodiment one

Please refer to Figs. 1-3, the present invention is a "ten"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams, comprising the following steps:

a. There is a track uphill 2 between the transport uphill 1 and the return air uphill. The track uphill 2 is connected with the transport alley 4 through the parking lot. The return air uphill 3 is connected with the return air alley 6 parallel to the transport alley 4. A cutout 8 is connected between the level roadway 6 and the transport levelway 4, and the return air uphill 3 is located at the junction with the bottom pumping wayway 5 and begins to excavate the bottom pumping wayway 5 until reaching the right below the cutout wayway 8.

b. After the construction of the bottom pumping roadway 5 is completed, a drilling site will be constructed every 50m in the bottom pumping roadway 5, and two inclined upward fracturing drilling holes 7 will be constructed in each drilling site of the bottom pumping roadway 5, located at the same The angle between the two fracturing holes 7 in the drilling field is 60°, so that the final hole of the fracturing holes 7 is located in the middle of the thickness of the coal seam 9, and the diameter of the fracturing holes 7 is 94mm. From the final hole of the fracturing borehole 7, the "ten"-shaped borehole 10 is constructed so that the "ten"-shaped borehole 10 is completely in the coal seam 9; the "ten"-shaped borehole 10 is 50m long and 94mm in diameter.

c. After the construction of the fracturing borehole 7 is completed, each fracturing borehole 7 is sealed with Jiumina filling material.

d. After the fracturing borehole 7 and the "ten"-shaped borehole 10 are sealed, each fracturing borehole 7 is subjected to hydraulic fracturing. The hydraulic fracturing process is divided into two stages. The first stage is conventional hydraulic fracturing. The fracturing stage refers to the stage of fracturing the coal seam with conventional hydraulic fracturing; the second stage is the sandy hydraulic fracturing stage, which means that in the process of hydraulic fracturing, the coal body is compressed under the action of high-pressure water. cracks, so that the pores and fissures in the coal body continue to develop and expand, forming a criss-cross fracture system in the coal body, and at the same time, the sand enters the cracks with high-pressure water, which produces a supporting effect on the cracks, thereby hindering the closure of the cracks and increasing the air permeability of the coal body 24 hours after the end of the conventional hydraulic fracturing stage, the sandy hydraulic fracturing stage was carried out.

e. 48 hours after the fracturing of each fracturing borehole 7 is completed, the hydraulic fracturing of the next fracturing borehole 7 is carried out until the hydraulic fracturing of the last fracturing borehole 7 is completed.

Embodiment two

This embodiment is basically the same as the first embodiment, except that the diameter of the fracturing borehole 7 is 90 mm.

Embodiment Three

This embodiment is basically the same as Embodiment 1, except that the diameter of the fracturing borehole 7 is 100 mm.

Embodiment four

This embodiment is basically the same as Embodiment 1, except that the angle between two fracturing boreholes 7 located in the same drilling field is 30°.

Embodiment five

This embodiment is basically the same as Embodiment 1, except that the angle between two fracturing boreholes 7 located in the same drilling field is 90°.

In the description of this specification, descriptions with reference to the terms "one embodiment", "example", "specific example" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment of the present invention. In an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are only to help illustrate the invention. The preferred embodiments are not exhaustive in all detail, nor are the inventions limited to specific embodiments described. Obviously, many modifications and variations can be made based on the contents of this specification. This description selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The invention is to be limited only by the claims, along with their full scope and equivalents.

Claims (6)

1. A "ten" font hydraulic fracturing permeability enhancement method for high gas coal seam, characterized in that it comprises the steps: a. There is a track uphill between the transportation uphill and the return air uphill. The track uphill is connected with the transportation alley through the parking lot. The return air uphill is connected with the return air alley parallel to the transportation alley. There is a cut-out hole connected between them, and the return air uphill is located at the connection with the bottom pumping roadway, and the bottom pumping roadway is excavated until it reaches the bottom of the cut-out hole; b. After the construction of the bottom pumping roadway is completed, a drilling site will be constructed every 30-60m in the bottom pumping roadway, and two inclined upward fracturing drill holes will be constructed in each drilling site of the bottom pumping roadway. The diameter is 90-100mm, so that the final hole of the fracturing drilling is located in the middle of the coal seam thickness, and the "ten"-shaped drilling is constructed from the final hole of the fracturing drilling, so that the "ten"-shaped drilling is completely in the coal seam; c. After the fracturing drilling and the "ten"-shaped drilling are completed, each fracturing drilling is sealed; d. After the fracturing drilling is sealed, hydraulic fracturing is performed on each fracturing drilling. The hydraulic fracturing process is divided into two stages. The first stage is the conventional hydraulic fracturing stage, which refers to the use of conventional hydraulic fracturing The stage of fracturing the coal seam; the second stage is the sandy hydraulic fracturing stage, which means that in the process of hydraulic fracturing, the coal body is fractured under the action of high-pressure water, so that the pores and fissures in the coal body continue to develop, Expansion, forming a criss-cross fracture system in the coal body, and at the same time, sand enters the fractures with high-pressure water, which produces a supporting effect on the fractures, thereby hindering the closure of the fractures and increasing the gas permeability of the coal body; the conventional hydraulic fracturing stage ends 24 Hours later, the sandy hydraulic fracturing stage is carried out; e. 48 hours after the fracturing of each fracturing hole, the hydraulic fracturing of the next fracturing hole is carried out until the hydraulic fracturing of the last fracturing hole is completed. 2. The "ten"-shaped hydraulic fracturing anti-permeability method for high gassy coal seams according to claim 1, characterized in that: a drilling site is constructed every 50m in the bottom pumping roadway. 3. The "ten"-shaped hydraulic fracturing anti-permeability method for high gassy coal seams according to claim 1, characterized in that: the angle between two fracturing boreholes located in the same drill field is 30-90° °. 4. The "cross"-shaped hydraulic fracturing anti-permeability method for high gassy coal seams according to claim 1, characterized in that: the "cross"-shaped borehole is 50m long and 94mm in diameter. 5. The "ten"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams according to claim 1, characterized in that: after the fracturing drilling is completed, the holes are sealed with Jiumina filling material. 6. The "cross"-shaped hydraulic fracturing anti-permeability method for high-gas coal seams according to claim 5, characterized in that: the fracturing drilling holes are sealed to the bottom of the coal seam.