CN114814094A - Experimental device and experimental method for visually simulating gas drilling and sealing - Google Patents

Abstract

An experimental device and a test method for visually simulating gas drilling and sealing, wherein the device comprises: a drilling simulation system, the system comprises an experimental box whose at least one side is made of transparent material, and the experimental box is filled with a filler for forming a simulated coal body; The grouting system includes a grouting pump, a grouting pipe, a pressure gauge and a flow meter. The grouting pump is connected to the borehole through the grouting pipe to inject the slurry of the sealing material added with phosphor powder into the borehole. The pressure gauge and the The flow meter is set on the grouting pipe to monitor the pressure and flow in the grouting pipe during grouting; the visual observation system is used to record the slurry in the borehole through images when the slurry of the sealing material is injected into the borehole. Osmosis diffusion in peripore fractures. The optimal process parameters of the sealing material and the sealing material with the optimal ratio determined by the invention are applied to the grouting and sealing of the actual gas drainage drilling hole, so that the sealing material forms a whole with the coal body after solidification, and sticks to the grouting hole. Good knot and high strength.

Description

An experimental device and experimental method for visual simulation of gas drilling and sealing

technical field

The invention relates to the field of experimental devices for sealing materials, in particular to an experimental device and an experimental method for visually simulating gas drilling and sealing.

Background technique

There are many mines with high gas and low permeability in my country, and the problem of gas control is more serious. Gas is an important factor that threatens the safe production of coal mines, and the most critical measure to reduce gas content is gas extraction. At present, the gas extraction efficiency of most mines in my country is not high, and a key factor affecting the gas extraction efficiency is the sealing method. The sealing method is an important part of gas drainage. If the sealing method is unreasonable, it will directly lead to low gas drainage efficiency.

At present, the main sealing methods in my country are grouting and sealing. When grouting and sealing, the flow and penetration of the grouting slurry in the coal seam cannot be observed with the naked eye, so it is difficult to determine the appropriate grouting pressure or flow. When the grouting pressure or When the flow rate is insufficient, it is difficult for grouting to penetrate into the cracks around the hole (the cracks around the hole refer to the cracks around the hole) and cannot seal the cracks around the borehole, that is, it does not play a role in sealing and sealing the area where the cracks develop, resulting in the passage of air. The leakage channel enters the borehole, resulting in low gas drainage efficiency.

Since the fluidity, viscosity and retardation time of different materials of the sealing material are different, the penetration and expansion of the fissures around the hole are also different when injected into the borehole under different pressures and flow rates. Hole grouting process parameters (grouting pressure, flow rate and time) generally rely on experience, that is, when the grouting pressure of the hole remains unchanged, it is considered that the grouting slurry is full and grouting is not required. This subjective judgment is not rigorous. There is a lack of experimental guidance on how to determine the optimal process parameters for its implantation and how to determine the best sealing material. Therefore, there is an urgent need for an experimental device that can simulate the environment of downhole drilling, and the optimal grouting process can be determined through the experimental method, so as to guide the actual grouting construction on site according to the experimental data.

SUMMARY OF THE INVENTION

In order to solve the above technical problems existing in the prior art, the present invention provides an experimental device and an experimental method for visually simulating gas drilling and sealing.

In order to achieve the above purpose, the present invention provides an experimental device for visual simulation of gas drilling and sealing, which includes:

A drilling simulation system for simulating a downhole drilling environment, the drilling simulation system includes an experimental box with at least one side made of transparent material, the experimental box is filled with a filler for forming a simulated coal body, and the simulated coal body is A loading mechanism is crimped on the top of the packing, and a drill hole is arranged in the packing;

A grouting system for simulating a downhole grouting process, the grouting system includes a grouting pump, a grouting pipe, a pressure gauge and a flow meter, and the grouting pump is connected to the borehole through the grouting pipe to for injecting the slurry of the plugging material added with phosphor powder into the borehole, the pressure gauge and the flow meter are arranged on the grouting pipe to monitor the pressure and flow in the grouting pipe during grouting; and

A visual observation system is used for recording the penetration and diffusion of the slurry in the peri-hole fissures of the drilled hole through images when the slurry of the plugging material is injected into the drilled hole, the visual observation system includes a camera, and the focus of the camera is A side surface with transparent material is provided on the experimental box body.

As a further preferred technical solution of the present invention, the simulated coal body in the experimental box includes a gas storage space, a rock layer and a coal seam sequentially arranged from top to bottom, and the loading mechanism is sealed and connected to the top of the gas storage space through a steel plate ; The drilling simulation system further includes a temperature control device, and the heating device of the temperature control device is connected to the experimental box for drying the newly laid simulated coal in the experimental box.

As a further preferred technical solution of the present invention, the length, width and height of the experimental box are respectively 100cm, 20cm and 100cm, the height of the gas storage space is 20cm, the thickness of the rock layer is 20cm, and the thickness of the coal seam is 60cm.

As a further preferred technical solution of the present invention, the rock formation is formed by mixing river sand as aggregate and cement and water as binder, and the weight ratio of river sand, cement and water is 10:2:1.

As a further preferred technical solution of the present invention, the coal seam is formed by mixing pulverized coal, raw coal and corn meal, wherein the weight ratio of pulverized coal to raw coal is 2:8, and the particle size of the raw coal is 5 mm.

As a further preferred technical solution of the present invention, the center of the borehole is at the center of the coal seam, and the hole diameter φ of the borehole is 113 mm.

As a further preferred technical solution of the present invention, the experimental box is a box with a closed inner cavity, the surrounding of the experimental box is provided with seals for sealing the inner cavity, and the openings of the grouting pipe and the drilling are as follows: Sealed connection.

As a further preferred technical solution of the present invention, there are multiple cameras, and the multiple cameras are simultaneously gathered on one side of the experimental box with transparent material from different viewing angles to collect image information from different angles.

As a further preferred technical solution of the present invention, the visual observation system further includes an auxiliary light source and a computer, the auxiliary light source is used to provide a light source to assist the camera to perform image acquisition, and the computer is connected to the camera to acquire the acquired image information and Perform analytical processing.

According to another aspect of the present invention, the present invention also provides an experimental method using the experimental device for visually simulating gas drilling and sealing according to any of the above, comprising the following steps:

1) Filling the simulated underground drilling environment in the experimental box to form the simulated coal body, and set a loading mechanism on the top surface of the simulated coal body. After the simulated coal body is dried, a drilling rig is used to drill holes on the simulated coal body;

2) The grouting pump is sealed and connected to the borehole through the grouting pipe, the input end of the grouting pump is connected to the slurry barrel which provides the sealing material through the grouting pipe, and the pressure gauge and the flow meter are installed on the grouting pipe;

3) Focus the camera on the side of the experimental box with transparent material;

4) Start the grouting pump according to the preset pressure and preset flow to carry out grouting under pressure. The camera collects the image information of the infiltration of the slurry in the simulated coal body during the grouting process. When the slurry flows to the inner crack tip of the simulated coal body and When it cannot flow, it is determined that the grouting is completed, otherwise the grouting continues; when the grouting is completed, the grouting pump is turned off, and the time used for grouting is recorded;

5) Repeat steps 1)-4) with the same sealing material and by changing the grouting pressure, flow rate and time, or with different sealing materials and with the same grouting pressure, flow rate and time, respectively. Collect image information of the infiltration of slurry in the simulated coal body during grouting;

6) Comprehensively compare and analyze the collected image information to obtain the optimal pressure, flow rate and time of the sealing material during grouting, or obtain the best ingredients and proportions of the sealing material.

The experimental device and the experimental method for visually simulating gas drilling and sealing of the present invention can achieve the following beneficial effects by adopting the above technical scheme:

1) The experimental device of the present invention performs pressure grouting on the borehole of the simulated coal body in the built borehole simulation system, and the visual observation system can accurately judge the time it takes for the slurry to flow to the tip of the fissure around the borehole, so as to determine Optimal grouting process parameters, such as grouting time, pressure and flow;

2) The experimental method of the present invention can be applied to evaluate the sealing quality of the sealing material to obtain the best ratio of raw materials. For example, the proportion of catalyst in the sealing material affects the solidification time of the material. The best proportion of catalyst can be determined by changing the penetration change of grouting during grouting, and by changing the raw material ratio of the sealing material to conduct repeated experiments.

3) The optimal process parameters of the sealing material obtained by the experimental device and the experimental method of the present invention and the sealing material of the optimal proportion are applied to the grouting sealing of the actual gas drainage drilling hole, so that the sealing material After solidification, it forms a whole with the coal body, with good cohesion and high strength, and the sealing material can seal the crack after flowing to the tip of the crack. After solidification, it will not shrink, and the crack can be repaired, thereby improving gas drainage. The sealing quality of the boreholes improves the gas drainage efficiency.

Description of drawings

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

1 is a schematic structural diagram of an example provided by an experimental device for visually simulating gas drilling and sealing according to the present invention;

2 is a schematic structural diagram of an example provided by the experimental box of the present invention;

Fig. 3 is the assembly schematic diagram of the visual observation system of the present invention;

4 is a diagram showing the solidification time of the sealing material after adjusting the proportion of the catalyst potassium isooctanoate in the sealing material.

In the picture: 1. Computer, 2. Camera, 3. Pressure gauge, 4. Flowmeter, 5. Grouting pump, 6. Grouting pipe, 7. Experimental box, 8. Temperature control device, 9. Drilling hole, 10. Auxiliary light source.

The object realization, functional features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Terms such as "up", "down", "left", "right", "middle" and "one" quoted in the preferred embodiment are only for the convenience of description and clarity, and are not intended to limit the scope of the present invention. The scope of implementation, the change or adjustment of the relative relationship, and the technical content without substantial change, shall also be regarded as the scope of implementation of the present invention.

As shown in Figures 1-3, the present invention provides an experimental device for visually simulating gas drilling and sealing, including:

The drilling simulation system is used to simulate the environment of the downhole drilling 9. The drilling simulation system includes an experimental box 7 whose at least one side is made of transparent material. The top of the simulated coal body is crimped with a loading mechanism to simulate the stress state of the coal body in the coal mine, the filler is provided with a drill hole 9 for simulating a gas drainage hole 9, and an experimental box 7 with a transparent material on the side is convenient for injection. The penetration of the slurry in the pores of the simulated coal body was observed during the slurry process. The simulated coal body in the experimental box 7 includes the gas storage space, the rock layer and the coal layer arranged in sequence from top to bottom, and the loading mechanism is sealed by a steel plate. Connected to the top of the gas storage space; the drilling simulation system also includes a temperature control device 8, and the heating device of the temperature control device 8 is connected to the experimental box 7 for new laying in the experimental box 7 simulated coal drying;

A grouting system for simulating a downhole grouting process, the grouting system includes a grouting pump 5 , a grouting pipe 6 , a pressure gauge 3 and a flow meter 4 , and the grouting pump 5 is connected through the grouting pipe 6 To the borehole 9 for injecting the slurry of the plugging material added with phosphor powder into the borehole 9, the pressure gauge 3 and the flow meter 4 are arranged on the grouting pipe 6 for monitoring grouting When the pressure and flow rate in the grouting pipe 6 are determined, the flow of the sealing material in the coal body can be easily observed by adding fluorescent powder. The fluorescent powder is yellow-green and oily, and does not interact with the polymer material (sealing material). reaction;

A visual observation system for recording the penetration and diffusion of the slurry in the peri-hole fissures of the drilled hole 9 through images when the slurry of the plugging material is injected into the drilled hole 9, the visual observation system includes a camera 2, and the camera The focal point of 2 is directly on the side of the experimental box 7 with a transparent material. The visual observation system also includes an auxiliary light source 10 and a computer 1. The auxiliary light source 10 is used to provide a light source to assist the camera 2 for image acquisition. The light source 10 is illuminated from both sides, so that the collected image information can avoid shadows and reflections as much as possible, and the computer 1 is connected with the camera 2 to obtain and analyze the collected image information.

In a specific embodiment, the length, width and height of the experimental box 7 are 100cm, 20cm, and 100cm respectively, the height of the gas storage space is 20cm, the thickness of the rock layer is 20cm, the thickness of the coal seam is 60cm, and the The center of the borehole 9 is at the center of the coal seam, and the hole diameter φ of the borehole 9 is 113 mm. The rock seam is formed by mixing river sand as aggregate and cement and water as binder, and the weight ratio of river sand, cement and water is 10:2:1; the coal seam is formed by mixing coal powder, raw coal and corn meal. The weight ratio of pulverized coal to raw coal is 2:8, the particle size of raw coal is 5mm, and the addition of corn flour can ensure that the coal seam has good air permeability.

Preferably, the experimental box 7 is a box with a closed inner cavity, the surrounding of the experimental box 7 is provided with a sealing member for sealing the inner cavity, and the opening of the grouting pipe 6 and the drilling hole 9 is a sealing connection .

Further preferably, there are multiple cameras 2, and multiple cameras 2 are simultaneously gathered on one side of the experimental box 7 with transparent materials from different viewing angles, so as to collect image information from different angles, and obtain clearer and more intuitive dynamics. images for subsequent analysis.

The present invention also provides an experimental method using an experimental device for visually simulating gas drilling and sealing, comprising the following steps:

1) Build a drilling simulation system: Fill the simulated underground hole 9 in the experimental box 7 with filler to form a simulated coal body, and set a loading mechanism on the top surface of the simulated coal body. After the simulated coal body is dried, use a drilling rig to Drill holes 9 on the simulated coal body;

2) Connection of the grouting system: the grouting pump 5 is sealed and connected to the borehole 9 through the grouting pipe 6, and the input end of the grouting pump 5 is connected to the slurry barrel that provides the sealing material through the grouting pipe. Install pressure gauge 3 and flow meter 4;

3) Visual observation system assembly: focus the camera 2 on the side of the experimental box 7 with transparent material;

4) Start the grouting pump 5 according to the preset pressure and preset flow to carry out grouting under pressure. The camera 2 collects the image information of the infiltration of the slurry in the simulated coal body during the grouting process. When the slurry flows into the internal cracks of the simulated coal body When the tip cannot flow, it is determined that the grouting is completed, otherwise the grouting continues; when the grouting is completed, the grouting pump 5 is turned off, and the time used for grouting is recorded;

5) Repeat steps 1)-4) with the same sealing material and by changing the grouting pressure, flow rate and time, or with different sealing materials and with the same grouting pressure, flow rate and time, respectively. Collect the image information of the infiltration of the slurry in the simulated coal body during grouting. The different sealing materials here refer to different ingredients or different proportions;

6) Comprehensively compare and analyze the collected image information to obtain the optimal pressure, flow rate and time of the sealing material during grouting, or obtain the best ingredients and proportions of the sealing material.

In this embodiment, the sealing material used is prepared by mixing the following ingredients and proportions (as shown in Table 1): polyether 305, polyether 204, flame retardant TCPP, stabilizer silicone oil, catalyst potassium isooctanoate, two Benzylmethane diisocyanate (MDI). The preparation steps are as follows: first, polyether 305, polyether 204, flame retardant TCPP, stabilizer silicone oil, and catalyst potassium isooctanoate are mixed with high precision in proportion to obtain a mixture; then diphenylmethane diisocyanate is added to the mixture , to obtain the slurry of the sealing material.

Table 1. Raw material ratio of sealing material

Repeat steps 1)-4) with different sealing materials (with different content of potassium isooctanoate as catalyst) and through the same grouting pressure, flow rate and time, respectively. The material can be adjusted by adjusting the proportion of catalyst in the material. By adjusting the solidification time of the material, the drilling hole 9 is sealed, so as to adjust the diffusion time of the sealing material in the coal and rock mass. The solidification time of the sealing material after adjusting the ratio is shown in Figure 4. The solidification time of the sealing material can be adjusted according to the length and range of the fissures around the 9 holes of the drilled hole. The optimal catalyst content can be determined through multiple sets of comparative experiments. When the catalyst content of potassium isooctanoate is 0.15% time is optimal.

In another specific implementation, considering different grouting pressures and grouting times, in this embodiment, the following three sets of tests are carried out respectively (each repeating the above steps 1)-4) is a set), the grouting pumps of each group are 5 The set grouting pressure is 0.5, 1, 1.5MPa, and the grouting time is 30, 60, 90s, and the pipeline is cleaned in time after a set of experiments is completed to prevent the residual liquid from condensing and blocking the pipeline. Finally, the acquired image information is compared to determine optimal pressure, flow and time parameters.

Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, and various changes or modifications can be made to the embodiments without departing from the principle and essence of the present invention. The scope of protection is limited only by the appended claims.

Claims (10)

1. an experimental device for visually simulating gas drilling and sealing, is characterized in that, comprises: A drilling simulation system for simulating a downhole drilling environment, the drilling simulation system includes an experimental box with at least one side made of transparent material, the experimental box is filled with a filler for forming a simulated coal body, and the simulated coal body is A loading mechanism is crimped on the top of the packing, and a drill hole is arranged in the packing; A grouting system for simulating a downhole grouting process, the grouting system includes a grouting pump, a grouting pipe, a pressure gauge and a flow meter, and the grouting pump is connected to the borehole through the grouting pipe to for injecting the slurry of the plugging material added with phosphor powder into the borehole, the pressure gauge and the flow meter are arranged on the grouting pipe to monitor the pressure and flow in the grouting pipe during grouting; and A visual observation system is used for recording the penetration and diffusion of the slurry in the peri-hole fissures of the drilled hole through images when the slurry of the plugging material is injected into the drilled hole, the visual observation system includes a camera, and the focus of the camera is A side surface with transparent material is provided on the experimental box body. 2. The experimental device for visually simulating gas drilling and sealing according to claim 1, wherein the simulated coal body in the experimental box comprises a gas storage space, a rock layer and a coal seam arranged in sequence from top to bottom, so The loading mechanism is sealed and connected to the top of the gas storage space through a steel plate; the drilling simulation system further includes a temperature control device, and the heating device of the temperature control device is connected to the experimental box, so as to be used to renew the experimental box. The laid simulated coal body is dried. 3. The experimental device for visual simulation of gas drilling and sealing according to claim 2, wherein the length, width and height of the experimental box are respectively 100cm, 20cm and 100cm, and the height of the gas storage space is 20cm, The thickness of the rock layer is 20cm, and the thickness of the coal layer is 60cm. 4. The experimental device for visually simulating gas drilling and sealing according to claim 2, wherein the rock formation is formed by mixing river sand as aggregate, and cement and water as binders, and river sand, cement and The weight ratio of water is 10:2:1. 5. The experimental device for visually simulating gas drilling and sealing according to claim 2, wherein the coal seam is formed by mixing pulverized coal, raw coal and corn meal, wherein the weight ratio of pulverized coal and raw coal is 2:8 , the particle size of the raw coal is 5mm. 6 . The experimental device for visual simulation of gas drilling and sealing according to claim 2 , wherein the center of the drilling is at the center of the coal seam, and the hole diameter φ of the drilling is 113 mm. 7 . 7. The experimental device for visually simulating gas drilling and sealing according to claim 1, wherein the experimental box is a box with a closed inner cavity, and the surrounding of the experimental box is provided with sealing its inner cavity The sealing member is sealed, and the grouting pipe is sealed with the opening of the drilled hole. 8 . The experimental device for visually simulating gas drilling and sealing according to claim 1 , wherein the number of cameras is multiple, and the multiple cameras are simultaneously gathered on a side surface with transparent material on the experimental box with different viewing angles. 9 . , to collect image information from different angles. 9. The experimental device for visually simulating gas drilling and sealing according to claim 1, wherein the visual observation system further comprises an auxiliary light source and a computer, and the auxiliary light source is used to provide a light source auxiliary camera for image acquisition, The computer is connected with the camera to obtain the collected image information and perform analysis and processing. 10. an experimental method that adopts the experimental device of the visual simulation gas drilling and sealing according to any one of claims 1-9, is characterized in that, comprises the following steps: 1) Filling the simulated underground drilling environment in the experimental box to form the simulated coal body, and set a loading mechanism on the top surface of the simulated coal body. After the simulated coal body is dried, a drilling rig is used to drill holes on the simulated coal body; 2) The grouting pump is sealed and connected to the borehole through the grouting pipe, the input end of the grouting pump is connected to the slurry barrel which provides the sealing material through the grouting pipe, and the pressure gauge and the flow meter are installed on the grouting pipe; 3) Focus the camera on the side of the experimental box with transparent material; 4) Start the grouting pump according to the preset pressure and preset flow to carry out grouting under pressure. The camera collects the image information of the infiltration of the slurry in the simulated coal body during the grouting process. When the slurry flows to the inner crack tip of the simulated coal body and When it cannot flow, it is determined that the grouting is completed, otherwise the grouting continues; when the grouting is completed, the grouting pump is turned off, and the time used for grouting is recorded; 5) Repeat steps 1)-4) with the same sealing material and by changing the grouting pressure, flow rate and time, or with different sealing materials and with the same grouting pressure, flow rate and time, respectively. Collect image information of the infiltration of slurry in the simulated coal body during grouting; 6) Comprehensively compare and analyze the collected image information to obtain the optimal pressure, flow rate and time of the sealing material during grouting, or obtain the best ingredients and proportions of the sealing material.

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