Experimental device and optimization method for optimizing laying parameters of deep coal rock proppant

Abstract

The invention discloses an experimental device for optimizing laying parameters of a deep coal rock proppant and an optimization method. The device comprises a constant-flux pump, and the output end of the constant-flux pump is sequentially connected with a first six-way valve, an intermediate container, a second six-way valve and an artificial fracture device through a pipeline; a pressure sensor and a measuring cylinder are respectively arranged at two ends of the artificial cracking device. The optimization method comprises the following steps: obtaining a deep coal rock fracture width distribution numerical simulation diagram based on numerical simulation, and assembling artificial fracture devices with different fracture widths according to the simulation diagram; then carrying out a compatibility experiment of the fiber, the fiber structure stabilizer and the crack to obtain a matching relation of the fiber, the fiber structure stabilizer and the crack width; based on the obtained matching relation of the fibers, the fiber structure stabilizer and the crack width, the deep coal rock proppant laying parameters are formed. The method solves the problem of sand blockage caused by rising of construction pressure due to adoption of fibers and fiber structure stabilizers with any parameters in the prior art.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil and gas reservoir reconstruction, and particularly relates to an experimental device for optimizing deep coal rock proppant placement parameters. BACKGROUND

[0002] Deep coal rock gas resources are rich in reserves and have broad exploration and development prospects. Deep coal rock has low Young's modulus and high Poisson's ratio. Compared with conventional reservoirs such as sandstone, the fracture width of deep coal rock is narrow, sanding is difficult, the proppant migration distance is limited, and the placement efficiency is low. In order to improve the sand-carrying performance of the liquid, the oil industry generally uses fiber auxiliary sand-carrying in the fracturing fluid to improve the sand-carrying performance of the fracturing fluid and improve the proppant sanding profile. With the continuous development of volume fracturing, the type of fracturing fluid changes from traditional cross-linked guar gum to low-viscosity slick water. The fiber escape rate in low-viscosity slick water is high, and it is difficult to effectively assist sand-carrying and improve the placement effect.

[0003] At present, the main process is to use fiber structure stabilizer to improve the dispersibility of fiber in the fracturing fluid, reduce the fiber escape rate in low-viscosity slick water, and greatly improve the migration distance of the proppant and the placement effect. However, due to the development of coal rock cleavage, large filtration loss, and strong plasticity, the fracture width is very narrow. However, when using fiber and fiber structure stabilizer, the fiber and fiber structure stabilizer addition parameters are not usually optimized according to the fracture width, which leads to an increase in construction pressure and causes sand plugging, affecting subsequent fracturing construction. SUMMARY

[0004] The purpose of the present application is to provide an experimental device for optimizing deep coal rock proppant placement parameters, which solves the problem of sand plugging caused by the increase in construction pressure due to the use of fiber and fiber structure stabilizer with arbitrary parameters in the prior art.

[0005] Another purpose of the present application is to provide an optimization method for deep coal rock proppant placement parameters.

[0006] The first technical solution adopted by the present application is an experimental device for optimizing deep coal rock proppant placement parameters, which comprises a horizontal flow pump, the output end of the horizontal flow pump is connected in sequence with a first six-way valve, an intermediate container, a second six-way valve and an artificial fracture device through a pipeline.

[0007] The inlet end of the artificial fracture device is provided with a pressure sensor for pressure detection, and the other end of the artificial fracture device is connected to a graduated cylinder through a pipeline. The fracture of the artificial fracture device is opened along the axial direction of the artificial fracture device.

[0008] The first technical solution of the present application is further characterized in that,

[0009] An artificial crack device consists of several crack tubes with the same or different crack widths, and adjacent crack tubes are connected by nuts.

[0010] The second technical solution adopted in this invention is a method for optimizing the placement parameters of deep coal and rock proppant, specifically including the following steps:

[0011] Step 1: Obtain a numerical simulation map of the width distribution of deep coal and rock fractures based on numerical simulation. Assemble artificial fracture devices with different fracture widths according to the simulation map. Connect the assembled artificial fracture device with a pressure sensor, a second six-way valve and a measuring cylinder.

[0012] Step 2: Conduct compatibility experiments between fibers and fiber structure stabilizers and cracks to obtain the matching relationship between fibers, fiber structure stabilizers and crack width.

[0013] Step 3: Based on the matching relationship between fiber, fiber structure stabilizer and joint width obtained in Step 2, the deep coal and rock proppant laying parameters are formed.

[0014] The second technical solution of the present invention is further characterized in that,

[0015] Step 2, the compatibility test between the fiber and the fiber structure stabilizer and the crack, specifically includes the following steps:

[0016] Step 2.1: Based on different crack widths, test the effect of fiber structure stabilizer content on pumping pressure;

[0017] Step 2.2: Based on different crack widths, test the effect of fiber size and addition amount on pumping pressure.

[0018] Step 2.1 specifically includes the following steps:

[0019] Step 2.1.1: Select a glass beaker, add water, drag reducer and quartz sand proppant into the glass beaker, and stir with a constant speed stirrer to obtain sand-carrying liquid;

[0020] Step 2.1.2: Pour the sand-carrying liquid into the intermediate container, seal it, and pressurize it with a horizontal flow pump so that the liquid flows through the artificial crack device with different crack widths at a constant flow rate of 30 mL / min. The pressure change at the crack inlet end is recorded by a pressure sensor.

[0021] Step 2.1.3: Add different amounts of fiber structure stabilizer to clean water, and repeat steps 2.1.1 and 2.1.2 to obtain the matching relationship between the fiber structure stabilizer and the crack.

[0022] In step 2.1.1, the constant speed stirrer rotates at 600 r / min to 800 r / min, and the stirring time is 3 min to 5 min; the drag-reducing agent added accounts for 0.4% of the liquid volume, and the quartz sand proppant is 70 mesh or 140 mesh, and the added quartz sand proppant accounts for 20% of the liquid volume.

[0023] The fiber structure stabilizer added in step 2.1.3 accounts for 0.3% to 0.5% of the liquid volume.

[0024] Step 2.2 specifically includes the following steps:

[0025] Step 2.2.1: Select a glass beaker, add water, drag reducer, quartz sand support agent, fiber and fiber structure stabilizer to the glass beaker, and stir with a constant speed stirrer to obtain sand-carrying liquid;

[0026] Step 2.2.2: Pour the sand-carrying liquid into the intermediate container, seal it, and pressurize it with a horizontal flow pump so that the liquid flows through the artificial crack device with different crack widths at a constant flow rate of 30 mL / min. The pressure change at the crack inlet end is recorded by a pressure sensor.

[0027] Step 2.2.3: Add different amounts of fiber to clean water, and repeat steps 2.2.1 and 2.2.2.

[0028] Step 2.2.4: Change the fiber size and repeat steps 2.2.1 to 2.2.3 to obtain the matching relationship between the fiber and the crack.

[0029] In step 2.2.1, the constant speed stirrer rotates at a speed of 600 r / min to 800 r / min, and the stirring time is 3 min to 5 min. The drag-reducing agent added accounts for 0.4% of the liquid volume, the quartz sand proppant is 70 mesh or 140 mesh, and the added quartz sand proppant accounts for 20% of the liquid volume; the fiber added accounts for 0.1% to 0.3% of the quartz sand proppant, and the fiber structure stabilizer added accounts for 0.3% to 0.5% of the liquid volume.

[0030] The beneficial effects of this invention are:

[0031] This invention provides a method for optimizing proppant placement parameters in deep coal and rock formations. By controlling the content of fiber structure stabilizer and the size and content of the fibers, the matching relationship between the fibers, fiber structure stabilizer, and joint width is achieved, resulting in optimized fiber and fiber structure stabilizer parameters. Furthermore, experimental simulations can effectively predict complex construction situations such as sand blockage, further optimizing the proppant placement parameters to ensure that the proppant can smoothly enter narrow joints, guaranteeing continuous sand addition and reducing construction risks.

[0032] The method for optimizing proppant placement parameters in deep coal and rock formations, as described in this invention, reduces the percentage of proppant placement with a sustained increase in pressure on the fracturing curve from 70% to 40%. Furthermore, it allows for longer transport distances, a larger effective support range, and microseismic data showing that the longest semi-fracture length has increased from 100 meters to 130 meters, which is beneficial for increasing the production of single wells in deep coal and rock formations. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the experimental apparatus for optimizing the proppant placement parameters in deep coal and rock formations according to the present invention.

[0034] Figure 2 This is a cross-sectional view of a single artificial fracture device in the experimental apparatus for optimizing the proppant placement parameters in deep coal and rock formations according to the present invention.

[0035] Figure 3 This is a cross-sectional view of the combined artificial fracture device in the experimental apparatus for optimizing the proppant placement parameters in deep coal and rock formations according to the present invention.

[0036] Figure 4a This is a side view of the 1mm artificial fracture device in the experimental apparatus for optimizing the proppant placement parameters of deep coal and rock according to the present invention.

[0037] Figure 4b This is a side view of the 2mm artificial fracture device in the experimental apparatus for optimizing the proppant placement parameters of deep coal and rock according to the present invention.

[0038] Figure 5 This is a numerical simulation diagram of the crack width distribution in Embodiment 4 of the present invention;

[0039] Figure 6 These are the pressure curves of blank samples without fiber structure stabilizer under 1mm and 2mm seam width conditions in Example 4 of the present invention;

[0040] Figure 7 This is the pressure curve of the fiber structure stabilizer added under a 1mm seam width condition in Example 4 of the present invention;

[0041] Figure 8 This is the pressure curve of the fiber structure stabilizer added under the condition of 2mm seam width in Example 4 of the present invention;

[0042] Figure 9 These are the pressure curves of adding different concentrations of 3mm fibers under a 1mm seam opening condition in Example 4 of this invention;

[0043] Figure 10 These are the pressure curves of adding different concentrations of 3mm fibers under a 2mm seam opening condition in Example 4 of this invention;

[0044] Figure 11These are the pressure curves of adding different concentrations of 6mm fibers under a 1mm seam opening condition in Example 4 of this invention;

[0045] Figure 12 This is the pressure curve of adding different concentrations of 6mm fibers under a 2mm seam condition in Example 4 of the present invention.

[0046] In the diagram, 1. Horizontal flow pump, 2. First six-way valve, 3. Intermediate container, 4. Second six-way valve, 5. Pressure sensor, 6. Artificial crack device, 7. Measuring cylinder. Detailed Implementation

[0047] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0048] This invention addresses the problems of existing experimental methods being unable to predict pressure rises and temporary blockages within fractures when fiber-insulated proppant is applied in reservoirs with dynamic fracture widths, as well as the lack of experimental methods to optimize the concentration of fiber and fiber structure stabilizer. It proposes an experimental apparatus for optimizing proppant placement parameters in deep coal and rock formations, and an optimization method for proppant placement parameters.

[0049] Example 1

[0050] like Figure 1 As shown, the experimental apparatus for optimizing the proppant placement parameters in deep coal and rock formations according to the present invention includes a horizontal flow pump 1. The horizontal flow pump 1 is connected in sequence to a first six-way valve 2, an intermediate container 3, a second six-way valve 4, and an artificial fracture device 6 via pipelines. A pressure sensor 5 is installed at the inlet end of the artificial fracture device 6, and the outlet end of the artificial fracture device 6 is connected to a measuring cylinder 7 via a pipeline.

[0051] like Figure 2 and Figure 3 As shown, the artificial fracture device 6 consists of several fracture tubes with the same or different fracture widths. Adjacent fracture tubes are connected by nuts, and the fractures in the artificial fracture device 6 are opened along the axial direction of the device. That is, the liquid entering the artificial fracture device 6 experiences pressure variations at the inlet end due to the influence of the fracture width. These pressure variations are detected by the pressure sensor 5. The liquid flowing through the fractures is guided by the pipes into a measuring cylinder, and the liquid content passing through the artificial fracture device can be read from the scale of the measuring cylinder.

[0052] like Figure 4a and Figure 4b As shown, there are two artificial crack devices: one with a crack width of 1 mm and the other with a crack width of 2 mm.

[0053] Example 2

[0054] The method for optimizing proppant placement parameters in deep coal and rock formations according to the present invention employs the aforementioned experimental apparatus for optimizing proppant placement parameters in deep coal and rock formations and is implemented according to the following steps:

[0055] Step 1: Based on numerical simulation, obtain a numerical simulation map of the distribution of deep coal and rock fracture widths. Based on the simulation map, assemble artificial fracture devices 6 with different fracture widths. The assembled artificial fracture device 6 is connected to the pressure sensor 5, the second six-way valve 4, and the measuring cylinder 7.

[0056] Step 2: Conduct compatibility experiments between fibers and fiber structure stabilizers and cracks to obtain the matching relationship between fibers, fiber structure stabilizers and crack width.

[0057] Step 3: Based on the matching relationship between fiber, fiber structure stabilizer and joint width obtained in Step 2, the deep coal and rock proppant laying parameters are formed.

[0058] Furthermore, step 2, the compatibility test between the fiber and the fiber structure stabilizer and the crack, specifically includes the following steps:

[0059] Step 2.1: Based on different crack widths, test the effect of fiber structure stabilizer content on pumping pressure;

[0060] Step 2.2: Based on different crack widths, test the effect of fiber size and addition amount on pumping pressure.

[0061] Step 2.2 is mainly based on Step 2.1, adding fibers and adjusting the size and amount of fibers added.

[0062] Example 3

[0063] Based on Example 2, step 2.1 of the method for optimizing the proppant placement parameters in deep coal and rock formations according to the present invention specifically includes the following steps:

[0064] Step 2.1.1: Select a glass beaker, add water, drag-reducing agent and quartz sand proppant into the glass beaker. The drag-reducing agent accounts for 0.4% of the liquid volume, and the quartz sand proppant is 70 mesh or 140 mesh, and the quartz sand proppant accounts for 20% of the liquid volume.

[0065] The sand-carrying liquid was obtained by stirring with a constant speed stirrer at a speed of 600 r / min to 800 r / min for 3 min to 5 min.

[0066] Step 2.1.2: Pour the sand-carrying liquid into the intermediate container, seal it, and pressurize it with the horizontal flow pump 1 so that the liquid flows through the artificial crack device 6 with different crack widths at a constant flow rate of 30 mL / min. The pressure change at the crack inlet end is recorded by the pressure sensor 5.

[0067] Step 2.1.3: Add 0.3% to 0.5% of the fiber structure stabilizer by volume to clean water, and repeat steps 2.1.1 and 2.1.2 to obtain the matching relationship between the fiber structure stabilizer and the crack.

[0068] Furthermore, step 2.2 specifically includes the following steps:

[0069] Step 2.2.1: Select a glass beaker, add water, drag-reducing agent, quartz sand support agent, fiber, and fiber structure stabilizer to the glass beaker. The fiber accounts for 0.1% to 0.3% of the quartz sand support agent, and the fiber structure stabilizer accounts for 0.3% to 0.5% of the liquid volume. Stir with a constant speed stirrer to obtain a sand-carrying liquid. The content of drag-reducing agent and quartz sand support agent, as well as the speed and stirring time of the constant speed stirrer, are the same as in step 2.1.1.

[0070] Step 2.2.2: Pour the sand-carrying liquid into the intermediate container, seal it, and pressurize it with the horizontal flow pump 1 so that the liquid flows through the artificial crack device 6 with different crack widths at a constant flow rate of 30 mL / min. The pressure change at the crack inlet end is recorded by the pressure sensor 5.

[0071] Step 2.2.3: Add different amounts of fiber to clean water, and repeat steps 2.2.1 and 2.2.2.

[0072] Step 2.2.4: Change the fiber size and repeat steps 2.2.1 to 2.2.3 to obtain the matching relationship between the fiber and the crack.

[0073] The proppant placement parameters obtained by the method of this invention for optimizing proppant placement parameters in deep coal and rock formations not only ensure that the proppant can smoothly enter the narrow fracture width, but also ensure continuous sand addition to reduce construction risks. The proportion of continuous pressure increase in the mine fracturing curve has decreased from 70% to 40%. Moreover, the transport distance is longer, the effective support range is larger, and the longest half-fracture length shown by microseismic data has increased from 100 meters to 130 meters, which is conducive to increasing the production of single wells in deep coal and rock formations.

[0074] Example 4

[0075] This embodiment obtains the size and order of fractures in deep coal and rock reservoirs based on numerical simulation, such as... Figure 5 As shown, numerical simulations reveal that artificial fractures in deep coal and rock formations are complex fracture systems with narrow fracture widths of 2.0 mm and 1.0 mm.

[0076] Based on the numerical simulation diagram, the crack widths were set to 2.0 mm and 1.0 mm. Both ends of a single cracked tube were machined into threads. Two cracked tubes were connected end to end with nuts to conduct a compatibility experiment between the fiber and the fiber structure stabilizer and the crack.

[0077] Specifically, the compatibility experiment between the fiber structure stabilizer and the crack:

[0078] First, a matching experiment was conducted between the crack tube with a crack width of 1 mm and the fiber structure stabilizer, which specifically included the following steps:

[0079] S1. Select a 500ml glass beaker, add 400ml of water, 1.6mL of drag-reducing agent (0.4% of the liquid volume), and 128g of 70-mesh quartz sand proppant (20% of the liquid volume). Stir with a constant speed stirrer at 700r / min for 3min to obtain the sand-carrying liquid.

[0080] S2, pour the sand-carrying solution prepared in S1 into the intermediate container 3, ensuring it is completely emptied. After sealing the container, connect the horizontal flow pump 1 to pressurize it. Set the fracture width to 1mm and displace the sand at a constant flow rate of 30mL / min. Record the pressure change at the fracture inlet. The pressure change is as follows: Figure 6 As shown.

[0081] S3, add 0.3%, 0.4%, and 0.5% of fiber structure stabilizer by volume to clean water, respectively. Repeat steps S1 and S2, and record the pressure change at the crack inlet. The pressure change is as follows: Figure 7 As shown.

[0082] Next, a matching experiment was conducted between the crack tube with a crack width of 2 mm and the fiber structure stabilizer:

[0083] With a crack span of 2mm, and only the crack width as a variable while keeping other parameters constant, repeat steps S1, S2, and S3 above. The pressure change at the crack inlet is as follows: Figure 8 As shown.

[0084] Depend on Figure 6 It can be seen that, when the same type of liquid is injected, the pressure at the inlet of a 1mm fracture is higher than that at the inlet of a 2mm fracture.

[0085] Depend on Figure 7 It can be seen that adding 0.3% fiber structure stabilizer to water results in a stable and relatively low overall pressure in a 1mm crack, while adding 0.4% and 0.5% fiber structure stabilizer results in higher pressure and greater fluctuations.

[0086] pass Figure 6 , Figure 7 and Figure 5 The comparison revealed that the addition of fiber structure stabilizer had virtually no impact on pressure under narrow gap widths and would not cause temporary blockage within the gap, thus affecting the proppant placement.

[0087] Compatibility experiment of fiber size and concentration with cracks:

[0088] First, a matching experiment was conducted between the 1mm crack width crack tube and the fiber size and concentration. The specific steps included:

[0089] S4. Select a 500ml glass beaker, add 400ml of water, 1.6mL of drag-reducing agent (0.4% of the liquid volume), 128g of 140-mesh quartz sand proppant (20% of the liquid volume), 0.128g of 3mm fiber (0.1% of the quartz sand proppant mass), and 1.2mL of fiber structure stabilizer (0.3% of the liquid volume). Stir with a constant speed stirrer at 800r / min for 4min to obtain the sand-carrying liquid.

[0090] S5, pour the sand-carrying solution prepared in S4 into intermediate container 3, ensuring it is completely emptied. After sealing the container, connect it to the horizontal flow pump 1 for pressurization. Set the fracture width to 1mm and displace the sand at a constant flow rate of 30mL / min. Record the pressure change at the fracture inlet. The pressure change is as follows: Figure 9 As shown.

[0091] S6, add 0.256g and 0.384g of 3mm fiber (0.2% and 0.3% of the proppant mass) to clean water respectively. Repeat steps S4 and S5, and record the pressure change at the crack inlet. The pressure change is as follows: Figure 9 As shown.

[0092] S7, change the fiber length to 6mm, repeat steps S4, S5, and S6 above, and record the pressure change at the crack inlet end. The pressure change is as follows: Figure 11 As shown.

[0093] Next, a matching experiment was conducted between the 2mm crack width crack tubes and the fiber size and concentration:

[0094] With a crack span of 2mm, and only the crack width as a variable while keeping other parameters constant, steps S4, S5, S6, and S7 are repeated. The pressure change at the crack inlet is shown below. Figure 10 and Figure 12 As shown.

[0095] Depend on Figure 9 It can be seen that for a 1mm crack, when the concentration of fiber with a length of 3mm is ≥0.2%, a temporary blockage phenomenon occurs in the crack; however, when the concentration of fiber with a length of 3mm is 0.1%, the pressure at the crack inlet is stable, and no temporary blockage phenomenon occurs in the crack.

[0096] Depend on Figure 10 It can be seen that for a 2mm crack, when the concentration of added fiber with a length of 3mm is 0.3%, a temporary blockage phenomenon occurs in the crack; when the concentration of added fiber with a length of 3mm is ≤0.2%, the pressure at the crack inlet is stable, and no temporary blockage phenomenon occurs in the crack.

[0097] Depend on Figure 11 and Figure 12 It can be seen that even when 0.1% of 6mm long fibers are added to a 1mm crack, temporary blockage will still occur in the crack, affecting the placement of the proppant.

[0098] Specifically, for cracks with a width of 1 mm, the preferred fiber size and concentration is 3 mm in length, with an addition concentration of 0.1% of the quartz sand proppant. For cracks with a width of 2 mm, the preferred fiber size and concentration is 3 mm in length, with an addition concentration not exceeding 0.2% of the quartz sand proppant mass.

[0099] In summary, when the crack width is 1mm (narrow crack width), the optimal proppant placement process parameters are as follows: fiber length 3mm, fiber concentration 0.1%, and fiber structure stabilizer concentration 0.3%; when the crack width is 2mm (narrow crack width), the optimal proppant placement process parameters are as follows: fiber length 3mm, fiber concentration 0.1%-0.2%, and fiber structure stabilizer concentration 0.3%.

Claims

1. An experimental device for deep coal rock proppant placement parameter optimization, characterized in that, The application relates to a device for deep coal rock supporting agent laying parameter optimization, which comprises a horizontal flow pump (1), and the output end of the horizontal flow pump (1) is sequentially connected with a first six-way valve (2), an intermediate container (3), a second six-way valve (4) and an artificial fracture device (6) through pipes. The inlet end of the artificial fracture device (6) is provided with a pressure sensor (5) for pressure detection, the other end of the artificial fracture device (6) is connected to a measuring cylinder (7) through a pipe, and the fractures of the artificial fracture device (6) are arranged along the axial direction of the artificial fracture device (6).

2. The experimental device for deep coal rock proppant placement parameter optimization of claim 1, wherein, The artificial fracture device (6) is composed of a plurality of fracture pipes with same or different fracture widths, and adjacent fracture pipes are connected through nuts.

3. A method for optimizing parameters of deep coal rock proppant placement, characterized in that, The experimental device for deep coal rock supporting agent laying parameter optimization is used, and the device specifically comprises the following steps: Step 1: based on numerical simulation, a deep coal rock fracture width distribution numerical simulation diagram is obtained, and different fracture width artificial fracture devices (6) are assembled according to the simulation diagram; the assembled artificial fracture device (6) is connected with the pressure sensor (5), the second six-way valve (4) and the measuring cylinder (7); Step 2: a compatibility experiment of the fiber and the fiber structure stabilizer with the fracture is carried out to obtain the matching relationship of the fiber, the fiber structure stabilizer and the fracture width; Step 3: based on the matching relationship of the fiber, the fiber structure stabilizer and the fracture width obtained in step 2, deep coal rock supporting agent laying parameters are formed.

4. The method for optimization of deep coal rock proppant placement parameters of claim 3, wherein, The compatibility experiment of the fiber and the fiber structure stabilizer with the fracture in step 2 specifically comprises the following steps: Step 2.1: based on different fracture widths, the influence of the fiber structure stabilizer content on the pump injection pressure is tested; Step 2.2: based on different fracture widths, the influence of the fiber size and the adding amount on the pump injection pressure is tested.

5. The method for optimization of deep coal rock proppant placement parameters of claim 4, wherein, Step 2.1 specifically comprises the following steps: Step 2.1.1: a glass beaker is selected, and water, a resistance reducing agent and quartz sand supporting agent are added into the glass beaker, and a constant speed stirrer is used for stirring to obtain a sand carrying liquid; Step 2.1.2: the sand carrying liquid is poured into the intermediate container (3), and after being sealed by covering, the liquid is pressurized by the horizontal flow pump (1) to flow through the artificial fracture device (6) with different fracture widths at a constant flow rate of 30mL / min, and the pressure change at the fracture inlet end is recorded by the pressure sensor (5); Step 2.1.3: different contents of the fiber structure stabilizer are added into the water, and steps 2.1.1 and 2.1.2 are repeated to obtain the matching relationship of the fiber structure stabilizer and the fracture.

6. The method for optimization of deep coal rock proppant placement parameters of claim 5, wherein, In step 2.1.1, the rotating speed of the constant speed stirrer is 600r / min-800r / min, and the stirring time is 3min-5min; the resistance reducing agent accounts for 0.4% of the liquid volume, the quartz sand supporting agent is 70 mesh or 140 mesh, and the quartz sand supporting agent accounts for 20% of the liquid volume.

7. The method for optimization of deep coal rock proppant placement parameters of claim 5, wherein, In step 2.1.3, the fiber structure stabilizer accounts for 0.3%-0.5% of the liquid volume.

8. The method for optimization of deep coal rock proppant placement parameters of claim 4, wherein, Step 2.2 specifically comprises the following steps: Step 2.2.1: a glass beaker is selected, and water, a resistance reducing agent, quartz sand supporting agent, a fiber and a fiber structure stabilizer are added into the glass beaker, and a constant speed stirrer is used for stirring to obtain a sand carrying liquid; Step 2.2.2, the sand-carrying fluid is poured into the intermediate container (3), and after being sealed with a cover, the fluid is pressurized by the horizontal flow pump (1), so that the fluid flows through the artificial fracture device (6) with different fracture widths at a constant flow rate of 30 mL / min, and the pressure change at the inlet end of the fracture is recorded by the pressure sensor (5) ; Step 2.2.3, different contents of fibers are added into the clean water, and steps 2.2.1 and 2.2.2 are repeated; Step 2.2.4, the size of the fiber is changed, and steps 2.2.1-2.2.3 are repeated to obtain the matching relationship between the fiber and the fracture.

9. The method for optimization of deep coal rock proppant placement parameters of claim 8, wherein, In the step 2.2.1, the rotating speed of the constant-speed stirrer is 600 r / min-800 r / min, and the stirring time is 3 min-5 min; the added resistance-reducing agent accounts for 0.4% of the volume of the fluid, the quartz sand proppant is 70 mesh or 140 mesh, and the added quartz sand proppant accounts for 20% of the volume of the fluid; the added fiber accounts for 0.1%-0.3% of the quartz sand proppant, and the added fiber structure stabilizer accounts for 0.3%-0.5% of the volume of the fluid.

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