Pulse type hydraulic fracturing device

Abstract

The utility model relates to the technical field of coal mine hydraulic fracturing, in particular to a pulse type hydraulic fracturing device. The device comprises a control system, a hydraulic fracturing assembly and a pulse generation assembly. The control system comprises a controller, a sensor group, a flow meter and a pressure gauge; the flow meter, the pressure gauge, the pressure sensor and the temperature sensor are connected with a controller to control the hydraulic fracturing assembly and the pulse generation assembly; the hydraulic fracturing assembly comprises a one-way valve, a throttler, a communicating pipe and a plugging device; the pulse generation assembly comprises a pulse generator, a high-pressure rubber pipe and a water tank. The hydraulic fracturing device is suitable for hydraulic fracturing after underground coal seam drilling. A pressurizing device of a hydraulic fracturing assembly is improved, an original constant injection pressure pump is converted into a pulse pressure pump capable of setting pulse mode water injection, the number of sensors at the water injection end and the number of sensors at the pressurizing end are increased, the pulse pressure, the pulse frequency and the pulse time are accurately controlled, the water injection fracturing effect is remarkably improved, and the permeability of a coal seam is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of coal mine hydraulic fracturing, in particular to a pulse hydraulic fracturing device. Background Art

[0002] Coal is a crucial energy source in China. With the increasing depletion of shallow coal seams, coal mining is gradually developing towards deeper areas. Therefore, the stress environment of coal bodies becomes more complex, bringing a more difficult and dangerous mining environment. Coal seam water injection is an important technical means to effectively prevent and control rock bursts and coal and gas outbursts. By continuously injecting pressure water into the coal body, the wettability and plasticity of the coal body are enhanced, and the mechanical properties of the coal are changed to reduce disaster risks.

[0003] In addition, the coal seam water injection technology also has a positive effect on preventing and controlling coal mine dust. The existing coal seam water injection first drills holes in the coal and rock through an underground drill. The drilling height is obtained according to theoretical prediction. After the drill hole reaches the predicted height, the fracturing end is placed into the drill hole for water injection fracturing. The pressure is kept constant during the water injection process, and the fracturing device is withdrawn after the fracturing is completed. However, the existing water injection fracturing device consumes a large amount of water, and the fracturing effect is not obvious. Therefore, a new water injection permeability enhancement technology is urgently needed for underground hydraulic fracturing to improve the water injection effect and generate a more complex fracture network. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a pulse hydraulic fracturing device, which can improve the water injection fracturing effect and the permeability of coal seams by setting a pulse generator and sensors at the water injection end and the pressure boosting end.

[0005] The adopted technical solution is as follows:

[0006] A pulse hydraulic fracturing device includes a control system, and also includes a hydraulic fracturing component and a pulse generating component;

[0007] The control system includes a controller, a sensor group, a flowmeter, and a pressure gauge; among them, the sensor group includes a pressure sensor and a temperature sensor; the flowmeter, the pressure gauge, the pressure sensor, and the temperature sensor are connected to the controller to control the hydraulic fracturing component and the pulse generating component;

[0008] The hydraulic fracturing component includes a check valve, a throttle, a connecting pipe, and a plugging device;

[0009] The pulse generating component includes a pulse generator, a high-pressure rubber hose, and a water tank.

[0010] Preferably, the plugging device includes a front plugging end and a rear plugging end. The connecting pipe, the rear plugging end, the throttle, the front plugging end, the pressure sensor, the throttle, and the check valve are connected in sequence, and the connecting pipe is connected to the high-pressure rubber hose.

[0011] Preferably, the other end of the high-pressure rubber hose is sequentially connected to a pulse generator and a water tank; the pulse generator is also connected to a controller.

[0012] Preferably, the pulse generator includes an electromagnetic driving device and a piston cylinder block. The water in the water tank flows through the piston cylinder block, a connecting pipe, a rear sealing end, a throttle, a front sealing end, a pressure sensor, a throttle, and a check valve through the high-pressure rubber hose; the electromagnetic driving device periodically drives the piston to move in the cylinder to achieve pulsed pressure output. The electromagnetic driving device drives the piston cylinder block to make the pressurized water enter the hydraulic fracturing assembly through the high-pressure rubber hose in a pulsed mode.

[0013] Preferably, a pressure gauge is installed on one side of the piston cylinder block to monitor the change of pulsed water pressure.

[0014] Preferably, the electromagnetic driving device includes a motor and a bearing box. Main shafts are respectively arranged in the centers of the motor and the bearing box, and the main shafts are connected through couplings; an inner magnetic cylinder, an isolation cover, and an outer magnetic cylinder are arranged around the main shaft in the bearing box from the inside to the outside. An impeller is arranged at the front end of the bearing box through the main shaft. The motor drives the impeller to rotate in a pulsed mode through the coupling under the action of the inner and outer magnets of the bearing box.

[0015] Preferably, a stop valve is arranged on one side of the piston cylinder block.

[0016] Preferably, a temperature sensor is installed on one side of the piston cylinder block to monitor the temperature change of the pulse generator.

[0017] Preferably, the flowmeter is installed on the high-pressure rubber hose between the pulse generator and the connecting pipe to detect the water flow.

[0018] Preferably, connecting valves are arranged on the high-pressure rubber hose between the water tank and the pulse generator and on the high-pressure rubber hose between the pulse generator and the connecting pipe. The connecting valves can be replaced by automatic valves, and the automatic valves are all connected to the controller and controlled by the controller to switch on and off to achieve automatic control.

[0019] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0020] Applying a pulsed hydraulic fracturing device of the present utility model is suitable for hydraulic fracturing after underground coal seam drilling. The pressurizing device of the hydraulic fracturing assembly is improved, so that the original constant injection pressure pump is transformed into a pulsed pressure pump (pulse generator) that can set the pulsed injection mode.

[0021] The present utility model increases the number of sensors at the water injection end and the pressure boosting end to achieve precise control of the pulse pressure, pulse frequency, and time. During the pulse fracturing process, the water pressure changes according to a preset function mode, and the pressure data changes in the water injection borehole are monitored in real time through a flow meter and a pressure sensor. The completion of the fracturing is judged based on the monitored data, significantly improving the water injection fracturing effect, being able to generate a more complex fracture network, and enhancing the permeability of the coal seam.

[0022] The pulse hydraulic fracturing device provided by the present utility model enriches the means of underground water injection fracturing, and has important practical value and broad popularization and application prospects for enhancing the fracturing effect and preventing floor accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a structural schematic diagram of the present utility model;

[0024] Figure 2 is a schematic diagram of the electromagnetic drive device of the present utility model

[0025] In the figure, 1 - controller, 2 - piston cylinder block, 3 - electromagnetic drive device, 4 - temperature sensor, 5 - stop valve, 6 - pressure gauge, 7 - water tank, 8 - flow meter, 9 - drill rig, 10 - high-pressure rubber hose, 11 - connecting pipe, 12 - rear plugging end, 13 - throttle, 14 - front plugging end, 15 - pressure sensor, 16 - check valve, 17 - impeller, 18 - isolation cover, 19 - outer magnetic cylinder, 20 - inner magnetic cylinder, 21 - bearing box, 22 - coupling, 23 - motor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The drawings are only for illustrative purposes; some well-known structures and their descriptions in the drawings may be omitted, and therefore, it cannot be understood as a limitation to the present utility model; the orientation names "upper", "lower", "front", "rear", "side", "inner", "outer", etc. are not limited to the descriptions in the embodiments.

[0027] The following further describes the present utility model in detail with reference to the drawings and embodiments.

[0028] Embodiment 1

[0029] A pulse hydraulic fracturing device includes a control system, and also includes a hydraulic fracturing assembly and a pulse generating assembly;

[0030] The control system includes a controller 1, a sensor group, a flow meter 8, and a pressure gauge 6; among them, the sensor group includes a pressure sensor 15 and a temperature sensor 4; the flow meter 8, the pressure gauge 6, the pressure sensor 15, and the temperature sensor 4 are connected to the controller 1 to control the hydraulic fracturing assembly and the pulse generating assembly;

[0031] The hydraulic fracturing assembly includes a check valve 16, a restrictor 13, a connecting pipe 11, and a plugging device;

[0032] The pulse generating assembly includes a pulse generator, a high-pressure rubber hose 10, and a water tank 7.

[0033] The plugging device includes a front plugging end 14 and a rear plugging end 12. The connecting pipe 11, the rear plugging end 12, the restrictor 13, the front plugging end 14, the pressure sensor 15, the restrictor 13, and the check valve 16 are connected in sequence. The connecting pipe 11 is connected to the high-pressure rubber hose 10. The other end of the high-pressure rubber hose 10 is connected to the pulse generator and the water tank 7 in sequence; the pulse generator is also connected to the controller 1.

[0034] Embodiment 2

[0035] A pulsed hydraulic fracturing device includes a control system, and also includes a hydraulic fracturing assembly and a pulse generating assembly;

[0036] The control system includes a controller 1, a sensor group, a flowmeter 8, and a pressure gauge 6; among them, the sensor group includes a pressure sensor 15 and a temperature sensor 4; the flowmeter 8, the pressure gauge 6, the pressure sensor 15, and the temperature sensor 4 are connected to the controller 1 to control the hydraulic fracturing assembly and the pulse generating assembly;

[0037] The hydraulic fracturing assembly includes a check valve 16, a restrictor 13, a connecting pipe 11, and a plugging device;

[0038] The pulse generating assembly includes a pulse generator, a high-pressure rubber hose 10, and a water tank 7.

[0039] The plugging device includes a front plugging end 14 and a rear plugging end 12. The connecting pipe 11, the rear plugging end 12, the restrictor 13, the front plugging end 14, the pressure sensor 15, the restrictor 13, and the check valve 16 are connected in sequence. The connecting pipe 11 is connected to the high-pressure rubber hose 10. The other end of the high-pressure rubber hose 10 is connected to the pulse generator and the water tank 7 in sequence; the pulse generator is also connected to the controller 1.

[0040] The pulse generator includes an electromagnetic driving device 3 and a piston cylinder block 2. Water in the water tank 7 flows through the piston cylinder block 2, the connecting pipe 11, the rear sealing end 12, the throttle 13, the front sealing end 14, the pressure sensor 15, the throttle 13, and the check valve 16 via a high-pressure rubber hose 10. The electromagnetic driving device 3 periodically drives the piston to move in the cylinder block 2 to achieve pulsed pressure output. The electromagnetic driving device 3 drives the piston cylinder block 2 to make the pressurized water enter the hydraulic fracturing assembly through the high-pressure rubber hose 10 in a pulsed mode. The electromagnetic driving device 3 includes a motor 23 and a bearing housing 21. Main shafts are respectively arranged at the centers of the motor 23 and the bearing housing 21, and the main shafts are connected by a coupling 22. An inner magnetic cylinder 20, an isolation cover 18, and an outer magnetic cylinder 19 are arranged around the main shaft in the bearing housing 21 from the inside to the outside. An impeller 17 is arranged at the front end of the bearing housing 21 through the main shaft. The motor 23 drives the impeller 17 to rotate in a pulsed mode through the coupling 22 under the action of the inner and outer magnets with the bearing housing 21.

[0041] A pressure gauge 6 is installed on one side of the piston cylinder block to monitor the change of pulsed water pressure.

[0042] Embodiment 3

[0043] As Figure 1 shown, a pulsed hydraulic fracturing device includes a control system, and also includes a hydraulic fracturing assembly and a pulse generating assembly;

[0044] The control system includes a controller 1, a sensor group, a flowmeter 8, and a pressure gauge 6. Among them, the sensor group includes a pressure sensor 15 and a temperature sensor 4. The flowmeter 8, the pressure gauge 6, the pressure sensor 15, and the temperature sensor 4 are connected to the controller 1 to control the hydraulic fracturing assembly and the pulse generating assembly;

[0045] The hydraulic fracturing assembly includes a check valve 16, a throttle 13, a connecting pipe 11, and a plugging device;

[0046] The pulse generating assembly includes a pulse generator, a high-pressure rubber hose 10, and a water tank 7.

[0047] The plugging device includes a front sealing end 14 and a rear sealing end 12. The connecting pipe 11, the rear sealing end 12, the throttle 13, the front sealing end 14, the pressure sensor 15, the throttle 13, and the check valve 16 are connected in sequence. The connecting pipe 11 is connected to the high-pressure rubber hose 10. The other end of the high-pressure rubber hose 10 is connected to the pulse generator and the water tank 7 in sequence. The pulse generator is also connected to the controller 1.

[0048] The pulse generator includes an electromagnetic driving device 3 and a piston cylinder block 2. Water in the water tank 7 flows through the piston cylinder block 2, the connecting pipe 11, the rear sealing end 12, the throttle 13, the front sealing end 14, the pressure sensor 15, the throttle 13, and the one-way valve 16 via the high-pressure rubber hose 10. The electromagnetic driving device 3 periodically drives the piston to move in the cylinder block 2 to achieve pulsed pressure output. The electromagnetic driving device 3 drives the piston cylinder block 2 to make the pressurized water enter the hydraulic fracturing assembly through the high-pressure rubber hose 10 in a pulsed mode.

[0049] As Figure 2 shown, the electromagnetic driving device 3 includes a motor 23 and a bearing box 21. Main shafts are respectively arranged in the centers of the motor 23 and the bearing box 21, and the main shafts are connected by a coupling 22. An inner magnetic cylinder 20, an isolation cover 18, and an outer magnetic cylinder 19 are arranged around the main shaft in the bearing box 21 from the inside to the outside. An impeller 17 is arranged at the front end of the bearing box 21 through the main shaft. The motor 23 drives the impeller 17 to rotate in a pulsed mode through the coupling 22 under the action of the inner and outer magnets with the bearing box 21.

[0050] The pressure gauge 6 and the temperature sensor 4 are respectively installed on one side of the piston cylinder block to monitor the pulsed water pressure change and the temperature change to prevent high-temperature damage, and the pressure sensor is used to monitor the pulsed water pressure change. A stop valve 5 is arranged on one side of the piston cylinder block 2. After the water injection is completed, the water pressure in the fracturing section can be discharged by using the connecting pipe 11 and the stop valve 5. The flowmeter is installed on the high-pressure rubber hose between the pulse generator and the connecting pipe to detect the water flow rate. The flowmeter 8, the pressure gauge 6, the pressure sensor 15, and the temperature sensor 4 transmit data signals to the controller for monitoring and control.

[0051] An operation method of a pulsed hydraulic fracturing device includes the following steps:

[0052] Step 1: Connect the one-way valve, the whipstock, the throttle, the connecting pipe, the packer, and the pressure sensor in sequence to form a hydraulic fracturing assembly. In the void drilled by the drill rig, use a tractor to push the hydraulic fracturing assembly to the top of the hole.

[0053] Step 2: First, turn on the control system to ensure the normal operation of the sensor group and the controller. Secondly, turn on the pulse generating assembly and confirm the normal operation of the electromagnetic driving device and the piston cylinder block.

[0054] Open the water tank valve to connect the water tank with the pulse generator, and make the water in the water tank enter the piston cylinder block through the connecting pipeline until the cavity of the piston cylinder block is filled with water.

[0055] Step 3: Set the frequency and time of the pulse through the controller, open the connection valve connecting the hydraulic fracturing assembly, so that the fracturing water can enter the hydraulic fracturing assembly. Through the controller, the fracturing water enters the hydraulic fracturing assembly under the push of the pulse generator in a certain functional pressure change mode, and observe and record the pressure scale of the water pressure gauge and the flow count of the flow meter.

[0056] Step 4:

[0057] During the water injection process, the water pressure condition of the fracturing system is monitored in real time through the controller and the sensor group. After the water injection is completed, the water pressure in the fracturing section is discharged by using the stop valve. After the water pressure is emptied, close the water tank valve, the hydraulic fracturing assembly and the pulse generator.

[0058] In the description of the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" should be understood in a broad sense. If there is no specific description of the connection method, conventional means such as bolts, rivets, welding in the prior art are adopted. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0059] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essence of the present invention should also belong to the protection scope of the present invention.

Claims

1. A pulsed hydraulic fracturing device, characterized in that, It includes a control system, and also includes a hydraulic fracturing assembly and a pulse generating assembly; The control system includes a controller, a sensor group, a flowmeter, and a pressure gauge; among them, the sensor group includes a pressure sensor and a temperature sensor; the flowmeter, the pressure gauge, the pressure sensor, and the temperature sensor are connected to the controller to control the hydraulic fracturing assembly and the pulse generating assembly; The hydraulic fracturing assembly includes a check valve, a restrictor, a connecting pipe, and a plugging device; The pulse generating assembly includes a pulse generator, a high-pressure hose, and a water tank.

2. The pulsed hydraulic fracturing device according to claim 1, characterized in that, The plugging device includes a front plugging end and a rear plugging end. The connecting pipe, the rear plugging end, the restrictor, the front plugging end, the pressure sensor, the restrictor, and the check valve are connected in sequence, and the connecting pipe is connected to the high-pressure hose.

3. The pulsed hydraulic fracturing device according to claim 2, characterized in that, The other end of the high-pressure hose is connected to the pulse generator and the water tank in sequence; the pulse generator is also connected to the controller.

4. The pulsed hydraulic fracturing device according to claim 3, wherein, The pulse generator includes an electromagnetic driving device and a piston cylinder block. The water in the water tank flows through the piston cylinder block, the connecting pipe, the rear plugging end, the restrictor, the front plugging end, the pressure sensor, the restrictor, and the check valve through the high-pressure hose; the electromagnetic driving device drives the piston cylinder block to make the pressurized water enter the hydraulic fracturing assembly in a pulse mode through the high-pressure hose.

5. The pulsed hydraulic fracturing device according to claim 4, wherein, The pressure gauge is installed on one side of the piston cylinder block to monitor the change of pulse water pressure.

6. The pulsed hydraulic fracturing device according to claim 4, characterized in that, The electromagnetic driving device includes a motor and a bearing box. Main shafts are respectively arranged in the center of the motor and the bearing box, and the main shafts are connected through couplings; an inner magnetic cylinder, an isolation cover, and an outer magnetic cylinder are arranged around the main shaft in the bearing box from the inside to the outside. An impeller is arranged at the front end of the bearing box through the main shaft. The motor is connected to the bearing box through a coupling and drives the impeller to rotate in a pulse mode under the action of the inner and outer magnets.

7. A pulsed hydraulic fracturing device according to claim 4, characterized in that, A stop valve is arranged on one side of the piston cylinder block.

8. A pulsed hydraulic fracturing device according to claim 4, characterized in that, The temperature sensor is installed on one side of the piston cylinder block to monitor the temperature change of the pulse generator.

9. A pulsed hydraulic fracturing device according to claim 1, characterized in that, The flowmeter is installed on the high-pressure hose between the pulse generator and the connecting pipe to detect the water flow.

10. A pulsed hydraulic fracturing device according to claim 1, characterized in that, Connecting valves are arranged on the high-pressure hose between the water tank and the pulse generator and on the high-pressure hose between the pulse generator and the connecting pipe.

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