A hydraulic fracturing apparatus

Abstract

The utility model discloses a hydraulic fracturing device, including water pump and barrier, the import end of water pump is connected with water tank, the export end of water pump is connected with the three way of water pipe, and one branch of three way is connected barrier through water pipe, and the other branch of three way is connected fracturing water injection pipe. First valve is set between three way and water pump, and first valve is stop valve, and second valve is set on the pipeline between three way and barrier, and third valve is set on the pipeline between three way and fracturing water injection pipe, and second valve and third valve are pressure -relief valve. The hydraulic fracturing device in the utility model weakens hard roof rock stratum, and roof collapses in time, and the working pressure of support is small when pressing, and the effect of roof control is good, and still has high security, low cost, construction speed is fast and strong adaptability and the like advantages, has better popularization value.

Description

Technical Field

[0001] This utility model relates to a hydraulic fracturing device, belonging to the field of coal mining technology. Background Technology

[0002] The No. 32 coal seam in Songhe Mine is located in the Emeishan Basalt Formation, with a dip angle of 26°–30°, averaging 28°. The average thickness of the coal seam is 2.8m. About 12m above the coal seam roof is hard basalt, with a thickness of 30m–40m and an f-value of approximately 14. The currently operating working face 113203 has a mineable strike length of 791m, a coal thickness of 2.5m, a specific gravity of 1.5, and recoverable reserves of approximately 448,000 tons. The coal seam dips at 30°. During mining, numerous problems, including severe mine pressure manifestation at the working face, are encountered, seriously hindering the safe and efficient mining of the No. 32 coal seam. The immediate roof of this coal seam is a typical high-strength, highly integral, and self-stabilizing fine sandstone and basalt roof. During the working face advance, the overhanging areas at the two ends of the working face are large and cannot collapse in time. If the pre-fracture blasting weakening method is used to deal with the difficult-to-collapse roof of the working face, it will lead to local CO accumulation. Measures to prevent gas explosions will also be required, which will increase the difficulty of safety management and is not conducive to safe production.

[0003] Therefore, there is an urgent need to develop a new device to promote the collapse of hard roofs during mining. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a hydraulic fracturing device to solve the technical problems existing in the prior art.

[0005] The technical solution adopted by this utility model is as follows: a hydraulic fracturing device, including a water pump and a barrier, wherein the inlet end of the water pump is connected to a water tank, and the outlet end of the water pump is connected to a tee via a water pipe, one branch of the tee is connected to the barrier via a water pipe, and the other branch of the tee is connected to a fracturing injection pipe; a first valve is provided between the tee and the water pump, the first valve being a shut-off valve, a second valve is provided on the pipeline between the tee and the barrier, and a third valve is provided on the pipeline between the tee and the fracturing injection pipe, wherein the second valve and the third valve are pressure relief valves.

[0006] Preferably, the water pump is a high-pressure water pump.

[0007] Preferably, the pressure of the water pump is above 20 MPa.

[0008] Preferably, a pressure gauge is installed on the tee.

[0009] 1. The beneficial effects of this utility model: Compared with the blasting control method in the prior art, the hydraulic fracturing device in this application is used to fracture the hard roof, the roof collapses in time, the support has low working resistance when pressure is applied, and the control effect is good; it also has the advantages of high safety, low cost, fast construction speed and strong adaptability, and has good promotion value.

[0010] 2. Compared with existing technologies, the hydraulic fracturing device described in this application is a safe, effective, and cost-efficient roof control technology. By using directional hydraulic fracturing and a combination of hydraulic fracturing and water injection, the strength and integrity of the hard roof can be significantly reduced, prompting the roof to collapse promptly during mining, weakening stress transmission, and controlling the manifestation of mine pressure.

[0011] 3. Compared with existing technologies, the hydraulic fracturing device described in this application significantly reduces costs for fracturing hard roofs. In practice, the cost per hole and material expenses for hydraulic fracturing are only about one-third of those for traditional blasting roof cutting techniques, and the cost per meter is as low as one-eighth. This cost advantage undoubtedly represents a significant saving for mining companies.

[0012] 4. Compared with existing technologies, this invention improves safety performance. It reduces the amount of explosives and detonators used in mines, fundamentally reducing the difficulty of procuring explosives and the dangers of blasting operations. Simultaneously, it avoids the problems of localized roof rock damage and air pollution caused by deep-hole pre-splitting blasting, providing workers with a safer working environment.

[0013] 5. Compared with existing technologies, the hydraulic fracturing device described in this application offers high efficiency for fracturing hard roofs. Hydraulic fracturing technology also has significant advantages in construction efficiency. By employing a segmented fracturing process (3-10 segments per hole), the pressure holding time is optimized to over 30 minutes, the control range per hole is expanded to 7-10 meters, the number of boreholes is reduced by approximately 90% (compared to deep-hole blasting), and normal production is not disrupted, greatly improving work efficiency.

[0014] 6. Compared with the prior art, the hydraulic fracturing device in this application is helpful for fracturing hard roofs and gas extraction. After fracturing, we make full use of the original fracturing holes for continuous extraction. We can extract gas from the coal seam through hydraulic fractures, reduce the gas content and gas pressure in the coal seam, reduce gas outbursts and releases during mining, and improve the safety of construction. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] The reference numerals in the accompanying drawings include: water pump 1, tee 2, first valve 3, second valve 4, third valve 5, drilling rig 6, drill rod 7, borehole 8, barrier 9, roof 10, coal seam 11, and pressure gauge 12. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1:

[0019] A hydraulic fracturing device, such as Figure 1 As shown, the system includes a water pump 1 and an isolator. The water pump 1 is a high-pressure water pump. A water tank is connected to the inlet of the water pump 1, and a tee 2 is connected to the outlet of the water pump 1 via a water pipe. A branch at the lower end of the tee 2 is connected to the isolator 9 via a water pipe, and a branch at the right end of the tee 2 is connected to a fracturing injection pipe. A first valve 3, which is a shut-off valve, is installed between the tee 2 and the water pump 1. A second valve 4 is installed on the pipeline between the tee 2 and the isolator 9, and a third valve 5 is installed on the pipeline between the tee 2 and the fracturing injection pipe. Both the second valve 4 and the third valve 5 are pressure relief valves.

[0020] In this embodiment, the pressure of water pump 1 is above 20 MPa.

[0021] In this embodiment, a pressure gauge 12 is installed on the tee 2.

[0022] The specific implementation process is as follows:

[0023] Step 1: Install the drilling rig 6 and drill rod 7. Drill fracturing borehole 8 inside the roof 10 above coal seam 11 according to design requirements. Check the integrity of borehole 8 and observe for any collapse. Then clean borehole 8 to ensure there is no significant debris or sediment accumulation. The operator of drilling rig 6 needs to record the location of mudstone or coal interlayers encountered while drilling borehole 8, and avoid fracturing these areas during subsequent fracturing operations.

[0024] Step 2: Install microseismic monitoring instruments in the 113203 return airway and the 113203 transport airway to monitor the initiation and propagation of hydraulic fracturing.

[0025] Step 3: Place the high-pressure water pump 1 and water tank at the designated location, connect the pipeline, install the pressure gauge 12, and perform debugging.

[0026] Step four: Seal the fracturing borehole 8 using the isolation device 9, then connect the high-pressure water pump 1 for hydraulic fracturing. According to design requirements, use either single-hole multiple fracturing or single-hole single fracturing. The single fracturing time is 10 minutes after fracturing initiation. The main process is as follows: connect the isolation device 9 → connect the injection pipe to borehole 8 → turn on the high-pressure water pump 1 → pressurize with the isolation device 9 → inject water for fracturing → stop the pump 10 minutes after water appears in the adjacent borehole or fracturing initiation → depressurize → begin the second stage of fracturing → cyclic fracturing. During pressurization, the operating details are as follows: close the first and third switches, open the second switch, start the water pump 1 to pressurize to 10MPa, wait for the pressure to stabilize and time for 2 to 3 minutes, then close the second switch. Continue pressurizing with the water pump 1 to 20MPa, open the first switch, wait for the pressure to stabilize, open the third switch and time for 10 to 15 minutes. After fracturing is completed, first turn off the first switch, then turn off the water pump 1, turn on the second switch to release pressure on the barrier 9, and finally turn on the third switch to release pressure on the fracturing water injection pipe to prevent mud and sand in the borehole 8 from being sucked back into the water pipe and affecting the normal operation of the barrier 9.

[0027] Step 5: Monitor in real time during the fracturing process. If abnormal noise or large-area water accumulation occurs in the top plate 10, immediately stop the fracturing. After the fracturing is completed, proceed to the next fracturing borehole 8 until all boreholes 8 are fracturing.

[0028] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A hydraulic fracturing device, characterized in that: The device includes a water pump and an isolator. The inlet of the water pump is connected to a water tank, and the outlet of the water pump is connected to a tee via a water pipe. One branch of the tee is connected to the isolator via a water pipe, and the other branch of the tee is connected to a fracturing injection pipe. A first valve, which is a shut-off valve, is installed between the tee and the water pump. A second valve is installed on the pipeline between the tee and the isolator, and a third valve is installed on the pipeline between the tee and the fracturing injection pipe. The second valve and the third valve are pressure relief valves.

2. The hydraulic fracturing device according to claim 1, characterized in that: The water pump is a high-pressure water pump.

3. The hydraulic fracturing device according to claim 1, characterized in that: The pressure of the water pump is above 20 MPa.

4. The hydraulic fracturing device according to claim 1, characterized in that: A pressure gauge is installed on the tee.

Images