CN105298433B - A kind of waterpower pressure, rush, take out integrated hole sealing device and method - Google Patents

Abstract

A hydraulic pressure, flushing and pumping integrated hole sealing device and method, including running a casing at one end of the borehole, injecting a plugging cement plug into the casing and the annular space of the borehole, and setting the casing outside the borehole. There is an inner flange integrated with the casing, a round hole is opened in the middle of the outer flange, and a conical hollow ferrule is welded around the round hole. The hydraulic fracturing pipe enters the borehole through the ferrule and the round hole, and the inner flange Bolted connection with the outer flange, hydraulic fracturing will be carried out after the ferrule and the hydraulic fracturing pipe are sealed; when gas is extracted, the drainage pipeline will be sealed and connected with the ferrule, and the inner and outer flanges will be bolted and then networked for drainage. The invention has the advantages of simple structure, convenient assembly and disassembly, fast sealing speed and good effect. A set of sealing device can be reused in multiple processes such as hydraulic fracturing, punching, gas drainage, etc. All stages of fracturing require temporary hole sealing and complicated procedures.

Description

Hole sealing device and method integrating hydraulic pressure, punching and pumping

technical field

The invention relates to a hole sealing technology for coal seam drilling, in particular to a hole sealing device and method integrating hydraulic pressure, punching and pumping in a coal mine.

Background technique

Gas disasters rank first among the five major disasters in my country's coal mines, including gas, water, fire, roof, and coal dust. loss. How to effectively prevent gas disasters has become an important problem that coal mine practitioners need to solve urgently.

With the in-depth development of research on pressure relief and anti-permeability technology for high-gassy and low-permeability coal seams, hydraulic measures such as hydraulic fracturing, hydraulic punching, and hydraulic pressure punching have been gradually applied. Hydraulic fracturing uses high-pressure water as the medium, and injects high-pressure and large-displacement liquid into the coal seam at an injection rate greater than the filtration rate. The tensile stress generated inside the coal seam causes damage to the weak place that first reaches the fracture pressure, and cracks are generated and developed inside the coal seam. , providing a "high-speed channel" for gas desorption and migration, which has the characteristics of a large disturbance range and is suitable for anti-permeability enhancement of hard coal seams; while hydraulic punching uses high-pressure water to cut and crush the coal body to flush out coal slag, making drilling The coal mass around the hole forms a cavity, and the coal mass around the borehole moves to the drilling direction by a large margin, causing the expansion deformation of the coal mass and the relative displacement between the roof and the floor, so that the stress in the area affected by the borehole is reduced and the pressure is completely relieved. , the cracks increase, and the air permeability of the coal seam increases. Hydraulic pressure flushing effectively combines hydraulic fracturing technology and hydraulic punching technology, making full use of the advantages that hydraulic fracturing technology can open, expand, and extend coal seam fissures, and hydraulic punching can release coal and relieve pressure. , and complement each other to form a more uniform drainage "seam network", which jointly improves the drainage efficiency. The test application shows that hydraulic pressure flushing has the characteristics of increasing the air permeability of coal seams, reducing ground stress and wide range of pressure relief. It has a remarkable effect on effectively controlling gas disasters and preventing gas safety accidents, especially for single, low permeability and high gas coal seams. Mining and hydraulic pressure flushing are being more and more widely used in gas prevention and control work.

Gas drainage by hydraulic pressure flushing involves many steps such as hydraulic fracturing, hydraulic punching, and network drainage. The success or failure of gas disaster prevention and control work. At present, there are mainly two kinds of existing sealing technologies: slurry sealing and packer sealing. The slurry type sealing is divided into two types: cement mortar sealing and polymer polyurethane foam sealing. The cement mortar has high compressive strength, but the sealing time is long. When deformed by ground stress, it is prone to air leakage; polyurethane organic foam materials have the advantages of high foaming ratio, light weight, and rapid hole sealing, but their compressive strength is low, and the sealing speed is difficult to control. In addition, the Such materials have problems such as excessive water expansion ratio, easy shrinkage after long-term storage, and separation from the wall of the drilled hole. In addition, the slurry-type hole sealing is mostly suitable for permanent hole sealing, and is not suitable for staged fracturing that requires multiple sealings. Moreover, when hydraulic punching is performed after staged hydraulic fracturing is completed, the hole needs to be re-expanded for slag removal. cumbersome. The hole sealing process of the packer is simple and can be recycled and reused, but the hole sealing of the packer has high requirements on the drilling quality, especially when the coal is soft and the stress concentration around the hole is affected by mining, the hole is prone to If the wall is uneven, there will be a gap between the packer and the hole wall, and the seal is not tight, which will affect the sealing effect. Due to the limitation of construction technology, the drilling trajectory is prone to deviation, and it is difficult for the packer to be lowered accurately according to the requirements. Default location.

Hydraulic fracturing requires sealing the hole to suppress pressure, while punching requires opening the hole to discharge slag, and drainage requires the hole to be tightly sealed before being connected to the network for drainage. However, the existing sealing technology is too complicated and cumbersome, and the sealing effect is limited. It is not suitable for hydraulic pressure punching to quickly seal and unseal the requirements. Therefore, it is urgent to find a convenient, fast, safe and efficient sealing technology integrating hydraulic fracturing, punching and drainage.

Contents of the invention

In order to solve the deficiencies in the prior art, the present invention provides a hydraulic pressure, punching and pumping integrated hole sealing device and method for fast, safe, economical and efficient hole sealing.

In order to solve the above technical problems, the present invention adopts the following technical scheme: a hydraulic pressure, punching and pumping integrated hole sealing device, including a casing, the outer end of the casing is provided with an inner flange concentric with the centerline of the casing, and the inner flange The blue bolt is connected with an outer flange, and the center of the outer flange is provided with a round hole. The outer surface of the outer flange is welded with a conical ferrule with the same center line. The outer contour of the axial section of the ferrule is trapezoidal. The included angle between the bus bar and the centerline of the outer flange is 3°-5°, the ferrule is provided with a through groove along the axial direction, the ferrule is externally threaded with three nuts, and the ferrule is provided with a through hole along the axial direction. The inner diameter of the through hole is equal to that of the circular hole, and the inner surface of the ferrule is provided with a sealing rubber tube along the axial direction of the through hole.

The casing is 8-10m long.

A sealing rubber pad is provided between the inner flange and the outer flange, and the center of the sealing rubber pad is transparent inside and outside.

The outer diameters of the three nuts increase sequentially from inside to outside.

The three nuts are pre-screwed on the ferrule before the ferrule and the outer flange are welded.

A hole sealing method integrating hydraulic pressure, punching and pumping, comprising the following steps:

(1) Run the casing with inner flange into the fracturing borehole;

(2) Use a grouting pump to inject cement slurry into the gap between the outer wall of the casing and the inner wall of the borehole to form a cylindrical plug;

(3) Pass the hydraulic fracturing pipe through the through hole in the center of the ferrule and the round hole in the center of the outer flange in sequence from the outside to the inside, and then lower it into the borehole;

(4) Place the sealing rubber pad between the inner flange and the outer flange, and use bolts to fix the inner flange and the outer flange so that the inner flange and the outer flange are sealed and connected, and the outer thread of the rotating ferrule The three nuts are connected, the nuts fasten the ferrule, and the gap of the through groove on the ferrule is narrowed, so that the sealing rubber cylinder and the hydraulic fracturing pipe are sealed and connected;

(5) Turn on the hydraulic fracturing pump, and the high-pressure water enters the target layer through the hydraulic fracturing pipe to perform hydraulic fracturing operations;

(6) Remove the connecting bolts between the inner flange and the outer flange, loosen the three nuts, withdraw the hydraulic fracturing pipe for a fracturing section length, and repeat steps (4) and (5) until the entire drilling is completed. Hole fracturing operations;

(7) Disassemble the connecting bolts between the inner flange and the outer flange, loosen the three nuts, pull out the hydraulic fracturing pipe, remove the outer flange and ferrule, and then run the high-pressure sealed drill pipe with the nozzle into the inside the borehole;

(8) Turn on the high-pressure water pump connected to the high-pressure sealed drill pipe, and the high-pressure water will perform hydraulic punching on the borehole through the high-pressure sealed drill pipe;

(9) Disassemble the connecting bolts between the inner flange and the outer flange, loosen the three nuts, pull out the high-pressure sealing drill pipe, and pass the extraction pipe through the through hole in the center of the ferrule and the center of the outer flange in turn from the outside to the inside After the round hole, go down into the drilled hole and repeat step (4);

(10) Turn on the gas drainage pump connected to the drainage pipe, and perform negative pressure drainage of the gas in the borehole after networking.

The inner diameter of the circular hole is 3-5 mm larger than the outer diameter of the hydraulic fracturing pipe, the high-pressure sealing drill pipe and the extraction pipe.

By adopting the above technical scheme, the present invention has the following beneficial effects:

The casing is lowered into the borehole, and the cement slurry injected into the annular space between the casing and the borehole can fully penetrate into the cracks around the borehole, effectively blocking the air leakage passages in the coal body around the crack zone at the borehole mouth. In the later stage, the grouting material solidifies and expands to form a plug, so that the casing is strongly anchored to the borehole. During hydraulic fracturing, the pressurized hydraulic fracturing pipe has a tendency to jump out of the drill hole under the action of the reaction force. At this time, the casing provides a pulling force to the outer flange through the inner flange, and is applied through three nuts. Providing friction between the ferrule and the hydraulic fracturing tubing prevents the hydraulic fracturing tubing from jumping out of the borehole. Secondly, the consolidated grouting material (plugging) can form a large supporting force on the borehole wall, effectively prevent the shrinkage and deformation of the grouting section to form new air leakage channels, and play a role in reducing the amount of air leakage in the borehole .

In summary, compared with the existing hole sealing technology, the present invention has simple structure, easy operation, convenient assembly and disassembly, easy replacement of damaged parts, and avoids the need for temporary sealing for each section of hydraulic fracturing in the past. Sealing, and the tedious work of destroying the previous sealing section and expanding the hole in order to re-seal the hole in the next stage of fracturing greatly saves time and improves work efficiency. The invention can be recycled and reused, saves the sealing material, improves the economic benefit of the enterprise, has strong operability, good market prospect, and is easy to popularize and apply.

Description of drawings

Fig. 1 is the structural representation of the present invention at the hole opening when hydraulic fracturing;

Fig. 2 is the structural representation at the hole opening of the present invention during hydraulic punching;

Fig. 3 is a schematic diagram of the structure at the hole opening of the present invention during gas drainage.

detailed description

As shown in Fig. 1-Fig. 3, a kind of hydraulic pressure, punching, pumping integrated hole sealing device of the present invention, comprises the sleeve pipe 2 of length 8m, and the outer end of sleeve pipe 2 is provided with the inside that is concentric with sleeve pipe 2. The flange 4 and the inner flange 4 are connected by bolts with an outer flange 6, and the center of the outer flange 6 is provided with a round hole, and the outer surface of the outer flange 6 is welded with a conical ferrule 7 with the same center line, and the ferrule 7 The outer contour of the axial section is trapezoidal, the angle between the bus bar of the ferrule 7 and the center line of the outer flange 6 is 3°, the ferrule 7 is provided with a through groove 13 along the axial direction, and the ferrule 7 is connected with three external threads The nut 8 and the inside of the ferrule 7 are provided with a through hole along the axial direction. The inner diameter of the through hole is equal to that of the round hole. The inner surface of the ferrule 7 is provided with a sealing rubber tube 9 along the axial direction of the through hole.

A sealing rubber pad 10 is provided between the inner flange 4 and the outer flange 6, and the center of the sealing rubber pad 10 is transparent inside and outside.

The outer diameters of the three nuts 8 increase sequentially from the inside to the outside.

Three nuts 8 are pre-screwed onto the ferrule 7 before the ferrule 7 and the outer flange 6 are welded.

A kind of hydraulic pressing, flushing, pumping integrated hole sealing method of the present invention comprises the following steps:

(1) Put the casing 2 and the grouting pipe with the inner flange 4 into the borehole 1, and the two ends of the inner casing 2 of the borehole 1 and the grouting pipe are wrapped with polyurethane dipped in the hole side. Cotton cloth strips, after the cotton cloth strips expand, two annular plugs are formed at both ends of the casing, and the middle of the two plugs is closed;

(2) Use a grouting pump to inject cement slurry into the annular space between the outer wall of the casing 2 and the inner wall of the borehole 1 through the grouting pipe to form a cylindrical plug 3;

(3) After the hydraulic fracturing pipe 5 passes through the through hole in the center of the ferrule 7 and the round hole in the center of the outer flange 6 from the outside to the inside, it is lowered into the drill hole 1;

(4) Place the sealing rubber gasket 10 between the inner flange 4 and the outer flange 6, and use bolts to connect the inner flange 4 and the outer flange 6 to make the seal between the inner flange 4 and the outer flange 6 Connect, rotate the three nuts 8 connected by external threads of the ferrule 7, the nuts 8 fasten the ferrule 7, and the gap between the grooves on the ferrule 7 is reduced, so that the sealing rubber cylinder 9 and the hydraulic fracturing pipe 5 are sealed and connected;

(5) Turn on the hydraulic fracturing pump, and the high-pressure water enters the target layer through the hydraulic fracturing pipe 5 to perform hydraulic fracturing operations;

(6) Disassemble the connecting bolts between the inner flange 4 and the outer flange 6, loosen the three nuts 8, withdraw the hydraulic fracturing tube 5 for a fracturing section length, and repeat steps (4) and (5), Until the fracturing operation of the entire borehole 1 is completed;

(7) Disassemble the connecting bolts between the inner flange 4 and the outer flange 6, loosen the three nuts 8, pull out the hydraulic fracturing tube 5, remove the outer flange 6 and ferrule 7, and then insert the The high-pressure sealed drill pipe 11 is lowered into the borehole 1;

(8) Turn on the high-pressure water pump connected to the high-pressure sealed drill pipe 11, and the high-pressure water passes through the high-pressure sealed drill pipe 11 to perform hydraulic punching on the borehole 1;

(9) Disassemble the connecting bolts between the inner flange 4 and the outer flange 6, loosen the three nuts 8, pull out the high-pressure sealing drill pipe 11, and pass the extraction pipe 12 through the channel in the center of the ferrule 7 from outside to inside. After the hole and the round hole in the center of the outer flange 6, lower it into the drill hole 1, and repeat step (4);

(10) Turn on the gas drainage pump connected to the drainage pipe 12, and carry out the drainage operation of the gas in the borehole 1 with the negative pressure connected to the network.

In addition, the inner diameter of the circular hole is 5 mm larger than the outer diameters of the hydraulic fracturing pipe 5 , the high-pressure sealing drill pipe 11 and the extraction pipe 12 .

This embodiment does not impose any formal restrictions on the shape, material, structure, etc. of the present invention. All simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention belong to the protection of the technical solution of the present invention. scope.

Claims (7)

1. a kind of waterpower pressure, rush, take out integrated hole sealing device, it is characterised in that：Including sleeve pipe, sleeve pipe outer end is provided with same with sleeve pipe The inner flange of center line, inner flange bolt connection has outward flange, and outward flange center offers circular hole, and outward flange outer surface is welded with With center line and in the cutting ferrule of cone shape, the outer contour of the axial section of cutting ferrule is trapezoidal, the bus and outward flange of cutting ferrule Centerlines be 3 ° -5 °, cutting ferrule is in axial direction provided with groove, and cutting ferrule external screw-thread is connected with three nuts, cutting ferrule Portion in axial direction offers through hole, and through hole is equal with bore inner diameter, and cutting ferrule inner surface is axially arranged with caulking gum cylinder along through hole.

2. according to claim 1 a kind of waterpower pressure, rush, take out integrated hole sealing device, it is characterised in that：Described sleeve pipe is long 8—10m。

3. according to claim 2 a kind of waterpower pressure, rush, take out integrated hole sealing device, it is characterised in that：The inner flange with It is provided between outward flange penetrating inside and outside sealing rubber pad, sealing rubber pad center.

4. according to claim 3 a kind of waterpower pressure, rush, take out integrated hole sealing device, it is characterised in that：Three nuts External diameter increase successively from inside to outside.

5. according to claim 4 a kind of waterpower pressure, rush, take out integrated hole sealing device, it is characterised in that：Three nuts It is screwed in advance on cutting ferrule before cutting ferrule and outward flange welding.

6. using a kind of waterpower pressure described in claim 5, the method for sealing for rushing, taking out integrated hole sealing device, it is characterised in that： Comprise the following steps：

（1）Sleeve pipe with inner flange is lowered into fracturing borehole；

（2）Cement mortar is injected to the space between sleeve outer wall and fracturing borehole inwall with grouting pump, columnar closure is formed Plug；

（3）Hydraulic fracturing pipe ecto-entad is sequentially passed through after the through hole at cutting ferrule center and the circular hole at outward flange center, tripping in pressure Split in drilling；

（4）Sealing rubber pad is placed between inner flange and outward flange, inner flange and outward flange is fixed using connecting bolt Connection, makes to be tightly connected between inner flange and outward flange, three nuts of rotation clip-sleeve external-thread connection, nut fastening cutting ferrule, Groove gap shrinks on cutting ferrule, make to be tightly connected between caulking gum cylinder and hydraulic fracturing pipe；

（5）Hydraulic fracturing pump is opened, water under high pressure enters target zone by hydraulic fracturing pipe and carries out hydraulic fracturing job；

（6）The connecting bolt between inner flange and outward flange is dismantled, unscrews three nuts, a pressure break will be removed outside hydraulic fracturing pipe Segment length, repeat step（4）、（5）, until completing the fracturing work of whole fracturing borehole；

（7）The connecting bolt between inner flange and outward flange is dismantled, unscrews three nuts, hydraulic fracturing pipe is extracted out, removes outer method Blue and cutting ferrule, then by the high pressure sealing drilling rod tripping in fracturing borehole with shower nozzle；

（8）The high-pressure hydraulic pump being connected with high pressure sealing drilling rod is opened, water under high pressure is implemented by high pressure sealing drilling rod to fracturing borehole Hydraulic flushing in hole；

（9）The connecting bolt between inner flange and outward flange is dismantled, unscrews three nuts, high pressure sealing drilling rod is extracted out, by extraction Pipe ecto-entad is sequentially passed through after the through hole at cutting ferrule center and the circular hole at outward flange center, in tripping in fracturing borehole, repeat step （4）；

（10）The gas pumping pump being connected with drainage tube is opened, negative pressure extraction work is carried out to the gas in fracturing borehole after networking Industry.

7. according to claim 6 a kind of waterpower pressure, rush, take out integrated method for sealing, it is characterised in that：The circular hole it is interior External diameter big 3-5mm of the footpath than hydraulic fracturing pipe, high pressure sealing drilling rod and drainage tube.