CN204436361U - A kind of underground coal mine Hydraulic fracturing pressure flow quantity intelligent adjusting device - Google Patents

Abstract

The utility model discloses an intelligent adjustment device for hydraulic fracturing pressure flow in a coal mine, which comprises a fracturing pipe extending into a fracturing borehole, a water injection main pipe connected at one end to the fracturing pipe, and a water injection main pipe connected at an output end to the other end of the water injection main pipe. The water pump, the water tank connected to the input end of the water pump, and the controller connected to the water pump. The pipeline of the water injection main pipe close to the water pump is connected to the water tank through a tee with a bypass pipe, and an electric ball valve is arranged on the bypass pipe. The controller It is connected with the control of the electric ball valve; a flow sensor and a pressure sensor are arranged on the pipeline close to the fracturing drilling of the main water injection pipe, and the controller communicates with the flow sensor and the pressure sensor. The utility model can realize accurate and stable real-time control of the water injection pressure and flow in the coal mine hydraulic fracturing operation, thereby improving the hydraulic fracturing effect.

Description

An intelligent adjustment device for hydraulic fracturing pressure and flow in coal mine

technical field

The utility model relates to coal bed gas mining equipment, in particular to a device for intelligently adjusting pressure and flow of hydraulic fracturing in coal mines.

Background technique

Coal mine underground hydraulic fracturing technology has been promoted in the fracturing of low-permeability outburst coal seams in Southwest China. Clean water is generally used as the fracturing medium and multi-plunger pumps are used as the driving force. Drilling and injection of high-pressure water to open fractures to strengthen coalbed methane extraction, however, due to the disorderly expansion of fractures and the serious damage to the roof and floor of the coal seam, the range of fracturing permeability enhancement is small and the support of the roof and floor during subsequent coal mining is difficult, etc. Problems have laid hidden dangers for underground safe production.

A crack initiation theory holds that after high-pressure water is pumped into the bedding plane, primary cracks, and new cracks created by drilling, internal water pressure will be generated when the water injection pressure is greater than the water loss pressure of the coal seam, and the internal water pressure will cause the coal seam to The wall of the weak surface breaks, and water enters the fractured crack, which further produces the next level of weak surface. According to the difference in shape and orientation of the fractures, the fractures are divided into main fractures and relatively small secondary fractures. Generally speaking, the secondary fractures around the main fractures can increase the gas pressure relief area and enhance the gas drainage effect. The expansion mode of fractures has a great relationship with water injection pressure and flow rate. It is an important purpose of fracturing reconstruction in low-permeability coal seams to create long diversion fractures at predetermined locations in the coal seam and promote the orderly expansion of fractures.

CN 202545207 U discloses an intelligent frequency conversion control fracturing pump unit, which uses the industrial computer system to remotely control the output speed of the frequency conversion motor to adjust the water injection pressure and flow rate, but the cost of the fracturing pump unit is relatively high and the structure is complex. In addition, CN202832457U discloses a remote intelligent control coal mine underground fracturing pump unit, which realizes the remote control of the industrial computer by the computer, and performs ultra-high pressure adjustment by controlling the hydraulic transmission. The pressure and flow sensors are installed at the pump end, and the pressure and flow data Can not reflect the real fracturing situation.

Utility model content

The purpose of the utility model is to provide a coal mine underground hydraulic fracturing pressure and flow intelligent adjustment device, which can realize the stable and balanced adjustment of water injection pressure and flow in underground fracturing.

The technical scheme of the utility model is as follows: an intelligent adjustment device for hydraulic fracturing pressure and flow in a coal mine, including a fracturing pipe extending into the fracturing borehole, a water injection main pipe connected at one end to the fracturing pipe, an output end and the other end of the water injection main pipe The connected water pump, the water tank connected to the input end of the water pump and the controller that controls the connected water pump, the pipeline of the water injection main pipe close to the water pump is connected to the water tank through a tee with a bypass pipe, and an electric ball valve is arranged on the bypass pipe. The controller is controlled and connected with the electric ball valve; a flow sensor and a pressure sensor are arranged on the pipeline of the water injection main pipe close to the fracturing drilling, and the controller is communicated with the flow sensor and the pressure sensor.

Further, the controller is a PLC controller, and the output of the controller is connected with a set of indicator lights.

Further, an overflow valve is connected between the water pump and the water tank.

Further, each port of the tee is connected with a flange sealing assembly.

Furthermore, the fracturing pipe is connected with the water injection main pipe through a quick joint.

This scheme forms a return flow bypass through the bypass pipe and the electric ball valve. After the controller performs a first-level coarse adjustment to the water pump, the controller controls the electric ball valve to realize a second-level fine adjustment, so that the water pressure in the water injection main pipe and The flow rate is easy to control and is in an accurate and stable control state, which is conducive to realizing the control of the expansion mode of fracturing fractures. Compared with the existing fracturing pump set with complex structure, it has the characteristics of simple structure and low cost. This scheme also facilitates the work of the on-site personnel by setting up the indicator light group; through the overflow valve to limit the pressure and overflow, the device is in a safe use state; and the use of flange sealing components and quick connectors is convenient for installation and maintenance, making this device more suitable for The working environment of coal mines.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Explanation of reference signs: 1-coal seam; 2-fracturing pipe; 3-water injection main pipe; 4-flow sensor; 5-pressure sensor; 6-controller; 7-indicator group; 8-tee; 9-electric ball valve 10-water pump; 11-overflow valve; 12-water tank; 13-fracturing drilling; 14-bypass pipe; 15-quick connector.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Referring to Fig. 1, the fracturing pipe 2 of the device is inserted into the fracturing borehole 13 directly reaching the coal seam 1, the outer end of the fracturing pipe 2 is connected to the water injection main pipe 3, and the other end of the water injection main pipe 3 is connected to the water pump 10, and the water pump 10 The input end is connected with a water tank 12, and the water pump 10 is controlled by the controller 6. After the water source in the water tank 12 is pressurized by the water pump 10, water is injected into the fracturing borehole 13 through the water injection main pipe 3 to carry out hydraulic fracturing, and the speed of water injection is roughly adjusted by the controller 6 . On this basis, add a bypass pipe 14 from the water tank 12 to the water injection main pipe 3 to form a return bypass. One end of the bypass pipe 14 is connected to the water tank 12, and the other end is connected to the water injection main pipe 3 close to the water pump 10 through the tee 8 , and an electric ball valve 9 is installed on the bypass pipe 14, the electric ball valve 9 is controlled by the controller 6, and the controller 6 further fine-tunes the water injection pressure in the water injection main pipe 3 by controlling the opening and closing of the electric ball valve 9. The water injection pressure value is preset in the controller 6, and the flow sensor 4 and the pressure sensor 5 are installed on the pipeline of the water injection main pipe 3 close to the fracturing borehole 13 to feed back the real-time flow and pressure values to the controller 6. The controller 6 compares the The water injection pressure value and the feedback value are preset to adjust the water pump 10 and the electric ball valve 9 .

The controller 6 can be a PLC controller or a single-chip microcomputer. For the convenience of instructing on-site operators, its output is connected with a group of indicator lights 7, and the lights of the group of indicator lights 7 are controlled according to the real-time flow value and pressure value. For the control mode of the controller 6 on the water pump 10 and the electric ball valve 9 and the on-off control of the indicator light group 7, refer to the related prior art, and will not repeat them here.

In order to ensure that the water pressure of the water injection main pipe 3 is stable, an overflow valve 11 is connected between the water pump 10 and the water tank 12 to achieve constant pressure overflow. In order to ensure the tightness, each port of the tee 8 is connected with a flange sealing assembly. For the convenience of construction, the fracturing pipe 2 and the water injection main pipe 3 are connected through a quick joint 15 .

Claims (5)

1. a underground coal mine Hydraulic fracturing pressure flow quantity intelligent adjusting device, comprise the pressure break pipe (2) stretching into pressure break boring (13), the water filling that one end is connected with pressure break pipe (2) is responsible for (3), output is responsible for the water pump (10) that (3) other end is connected with water filling, the water tank (12) be connected with the input of water pump (10) and the controller (6) of control connection water pump (10), it is characterized in that: described water filling supervisor (3) passes through to be connected with shunt valve (14) between threeway (8) and water tank (12) near the pipeline of water pump (10), shunt valve (14) is provided with electrical ball valve (9), controller (6) and electrical ball valve (9) control connection, water filling supervisor (3) is provided with flow transmitter (4) and pressure sensor (5) on the pipeline of pressure break boring (13), and controller (6) and flow transmitter (4), pressure sensor (5) communicate to connect.

2. underground coal mine Hydraulic fracturing pressure flow quantity intelligent adjusting device according to claim 1, is characterized in that: described controller (6) is PLC, and controller (6) exports and is connected with indicator lamp group (7).

3. underground coal mine Hydraulic fracturing pressure flow quantity intelligent adjusting device according to claim 1 and 2, is characterized in that: be connected with overflow valve (11) between described water pump (10) and water tank (12).

4. underground coal mine Hydraulic fracturing pressure flow quantity intelligent adjusting device according to claim 1 and 2, is characterized in that: each port of described threeway (8) is connected with flange seal assembly.

5. underground coal mine Hydraulic fracturing pressure flow quantity intelligent adjusting device according to claim 4, is characterized in that: described pressure break pipe (2) is responsible for (3) by snap joint (15) with water filling and is connected.